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1. Late Miocene onset of the modern Antarctic Circumpolar Current

Author: Australian Research Council, Ministère de l'Europe et des Affaires étrangères (France), Generalitat de Catalunya, International Ocean Discovery Program, Ministerio de Economía, Industria y Competitividad (España), UK Research and Innovation, Evangelinos, Dimitris, Etourneau, Johan, van de Flierdt, Tina, Crosta, Xavier, Jeandel, Catherine, Flores, José Abel, Harwood, David M., Valero, Luis, Ducassou, Emmanuelle, Sauermilch, Isabel, Klocker, Andreas, Cacho, Isabel, Pena, Leopoldo D., Kreissig, Katharina, Benoit, Mathie, Paredes, Eduardo, García-Solsona, Ester, López-Quirós, Adrián, Escutia, Carlota, Australian Research Council, Ministère de l'Europe et des Affaires étrangères (France), Generalitat de Catalunya, International Ocean Discovery Program, Ministerio de Economía, Industria y Competitividad (España), UK Research and Innovation, Evangelinos, Dimitris, Etourneau, Johan, van de Flierdt, Tina, Crosta, Xavier, Jeandel, Catherine, Flores, José Abel, Harwood, David M., Valero, Luis, Ducassou, Emmanuelle, Sauermilch, Isabel, Klocker, Andreas, Cacho, Isabel, Pena, Leopoldo D., Kreissig, Katharina, Benoit, Mathie, Paredes, Eduardo, García-Solsona, Ester, López-Quirós, Adrián, and Escutia, Carlota
Abstract: The Antarctic Circumpolar Current plays a pivotal role in global climate through its strong influence on the global overturning circulation, ocean heat and CO uptake. However, when and how the Antarctic Circumpolar Current reached its modern-like characteristics remains disputed. Here we present neodymium isotope and sortable silt records from sediment cores in the Southwest Pacific and South Indian oceans spanning the past 31 million years. Our data indicate that a circumpolar current like that of today did not exist before the late Miocene cooling. These findings suggest that the emergence of a homogeneous and deep-reaching strong Antarctic Circumpolar Current was not linked solely to the opening and deepening of Southern Ocean Gateways triggering continental-scale Antarctic Ice Sheet expansion during the Eocene–Oligocene Transition (∼34 Ma). Instead, we find that besides tectonic pre-conditioning, the expansion of the Antarctic Ice Sheet and sea ice since the middle Miocene Climate Transition (∼14 Ma) played a crucial role. This led to stronger density contrast and intensified Southern Westerly Winds across the Southern Ocean, establishing a vigorous deep-reaching circumpolar flow and an enhanced global overturning circulation, which amplified the late Cenozoic global cooling.
Published: 2024

2. Origin of Fe-Ca-Metasomatism in Exhumed Mantle Rocks at the MARK Area (23°N, ODP Leg 153) and Implications on the Formation of Ultramafic-Hosted Seafloor Massive Sulfide Deposits

Author: International Ocean Discovery Program, German Research Foundation, Institut national des sciences de l'Univers (France), Coltat, Remí, Andreani, M., Patten, C. G. C., Godard, M., Debret, B., Escartin, J., International Ocean Discovery Program, German Research Foundation, Institut national des sciences de l'Univers (France), Coltat, Remí, Andreani, M., Patten, C. G. C., Godard, M., Debret, B., and Escartin, J.
Abstract: At Mid-Ocean Ridges, hot, reduced, acidic, and metal-rich fluids are responsible for the formation of ultramafic-hosted seafloor massive sulfide deposits (UM-SMSs), where mantle exhumation efficiently operates. As UM-SMSs display great structural, mineralogical, and geochemical variabilities from site to site, a simple genetic model cannot be applied. Notably, fluid circulation and Fe-Ca metasomatism are reported in ultramafic-hosted hydrothermal deposits exposed in ophiolites, suggesting it might have genetic implications on the formation of mineralized systems. Similar Fe-Ca metasomatism was reported in drilled mantle rocks at the Mid Atlantic Ridge Kane (MARK) area, offering access to the vertical dimension beneath an exhumed oceanic core complex to provide an integrative study of the nature and geometry of deep magmatic and hydrothermal processes. At MARK, mantle rocks underwent complex processes of melt-rock and fluid-rock interactions. Magma channeling and interactions with surrounding rocks enriched mantle silicates in Fe, Co, and Zn. There, subsequent hydrothermal alteration allowed to stabilize Fe-rich silicates. Mineralogy and geochemistry of hydrothermal phases at MARK suggest mineral crystallization under temperatures from ∼830° down to 350°C during early mantle exhumation at a depth <6.5 km below seafloor, followed by serpentinization of the massif during progressive mantle denudation. Considering the lithological heterogeneity at (ultra)slow-spreading ridges, metal enrichment in deep mantle rocks during melt-rock interactions may be a widespread process. In ultramafic-dominated environments where extensional tectonics allow fluid flows to these deep zones, fluids may leach and transport metals to the surface, accounting for metal entrapment in UM-SMSs.
Published: 2023

3. Late Cenozoic sea-surface-temperature evolution of the South Atlantic Ocean

Author: International Ocean Discovery Program, Ministerio de Ciencia e Innovación (España), Dutch Research Council, Hoem, Frida S., López-Quirós, Adrián, Van De Lagemaat, Suzanna, Etourneau, Johan, Sicre, Marie-Alexandrine, Escutia, Carlota, Brinkhuis, Henk, Peterse, Francien, Sangiorgi, Francesca, Bijl, Peter K., International Ocean Discovery Program, Ministerio de Ciencia e Innovación (España), Dutch Research Council, Hoem, Frida S., López-Quirós, Adrián, Van De Lagemaat, Suzanna, Etourneau, Johan, Sicre, Marie-Alexandrine, Escutia, Carlota, Brinkhuis, Henk, Peterse, Francien, Sangiorgi, Francesca, and Bijl, Peter K.
Abstract: At present, a strong latitudinal sea-surface-temperature (SST) gradient of g1/4g€¯16g€¯g exists across the Southern Ocean, maintained by the Antarctic Circumpolar Current (ACC) and a set of complex frontal systems. Together with the Antarctic ice masses, this system has formed one of the most important global climate regulators. The timing of the onset of the ACC system, its development towards modern-day strength and the consequences for the latitudinal SST gradient around the southern Atlantic Ocean are still uncertain. Here we present new TEX86 (TetraEther indeX of tetraethers consisting of 86 carbon atoms)-derived SST records from two sites located east of Drake Passage (south-western South Atlantic) to assist in better understanding two critical time intervals of prominent climate transitions during the Cenozoic: the late Eocene-early Oligocene (Ocean Drilling Program, ODP, Site 696) and Middle-Late Miocene (IODP Site U1536) transitions. Our results show temperate conditions (20-11g€¯g) during the first time interval, with a weaker latitudinal SST gradient (g1/4g€¯8g€¯g) across the Atlantic sector of the Southern Ocean compared to present day. We ascribe the similarity in SSTs between Sites 696 and 511 in the late Eocene-early Oligocene South Atlantic to a persistent, strong subpolar gyre circulation connecting the sites, which can only exist in the absence of a strong throughflow across the Drake Passage. Surprisingly, the southern South Atlantic record Site 696 shows comparable SSTs (g1/4g€¯12-14g€¯g) during both the earliest Oligocene oxygen isotope step (EOIS, g1/4g€¯33.65g€¯Ma) and the Miocene Climatic Optimum (MCO, g1/4g€¯16.5g€¯Ma). Apparently, maximum Oligocene Antarctic ice volume could coexist with warm ice-proximal surface ocean conditions, while at similar ocean temperatures, the Middle Miocene Antarctic ice sheet was likely reduced. Only a few Middle-Late Miocene (discontinuous) high-latitude records exist due to ice advances causing unconformities
Published: 2023

4. Radiolarians and silicoflagellates as clues of the paleoceanographic history of Guaymas Basin in the Gulf of California during the past 31,000 yr

Author: Velázquez-Aguilar, Mauricio, primary, Pérez-Cruz, Ligia, additional, Urrutia-Fucugauchi, Jaime, additional, Aldama-Cervantes, Alejandro, additional, Venegas-Ferrer, Rafael, additional, Aiello, Ivano, additional, Jiang, Shijun, additional, Ran, Lihua, additional, Sarao, John, additional, Martínez, Priscilla, additional, Váldez-Hernández, Marysol, additional, and Expedition 385 Scientists, International Ocean Discovery Program, additional
Published: 2023
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5. Radiolarians and silicoflagellates as clues of the paleoceanographic history of Guaymas Basin in the Gulf of California during the past 31,000 yr

Author: Mauricio Velázquez-Aguilar, Ligia Pérez-Cruz, Jaime Urrutia-Fucugauchi, Alejandro Aldama-Cervantes, Rafael Venegas-Ferrer, Ivano Aiello, Shijun Jiang, Lihua Ran, John Sarao, Priscilla Martínez, Marysol Váldez-Hernández, and International Ocean Discovery Program Expedition 385 Scientists
Abstract: We investigated the changes in water masses circulation patterns in the Guaymas Basin in the Gulf of California to reveal the oceanographic and climatic evolution. We analyzed silica microfossils: Polycystine Radiolaria (hereafter radiolarians), and silicoflagellates, in the sediments of the deep-sea cores from Site U1545-A (~42 mbsf) of the IODP Expedition 385, collected on the west side of the basin.The age model is based on 17 AMS radiocarbon dates covering the last 31,000 yr, between MIS (Marine Isotope Stage) 3 and MIS 1. Sedimentation rates ranged between 0.88 to 2.02 mm/yr. The highest sedimentation rates (ranging from 1.61 to 2.1 mm/yr) are between ∼31,000 and 19,000 yr (including the Last Glacial Maximum, LGM), coinciding with falling sea level and a maximum ice volume. A total of 122 samples were analyzed, and 145 radiolarian taxa and 16 silicoflagellate species were identified. Radiolarians are rich, diverse, and well-preserved; overall, diversity is much higher for the last 15,000 yr.Factor analysis of radiolarian assemblages suggested regional oceanic patterns based on environmental affinities. The dominance of Siphocampe lineata, intermediate dweller radiolarian, was evident in the transition of MIS 3 to MIS 2, suggesting a significant influence of the Pacific Intermediate Water prior to the Last Glacial Maximum (LGM) and in Heinrich-1 (H-1), probably due to stronger North Pacific Intermediate Water (NPIW) formation. Besides, during the LGM, surface radiolarians assemblage and silicoflagellate specie such as Cycladophora davisiana and Botryostrobus aquilonaris, and Octactis speculum, supports the idea of an incursion of the California Current Water (CCW) into GB, possibly by the southward shift migration of the NPH (North Pacific High) system, caused by the polar jet displacement and, because of the weakened NW-winds as well as the strengthened poleward circulation into the gulf.The assemblage of Tetrapyle octacantha group and Phorticium pylonium group, surface dwellers radiolarians, and the silicoflagellate Dictyocha fibula var. messanensis indicated the dominance of Tropical Surface Water related to warm conditions and the influence of tropical water incursions enhanced by the Costa Rica Current. This association becomes more evident during the BA (Bolling Allerod) and the Holocene, mainly during the HTM (Holocene Thermal Maximum).Surface dwellers species (Lithomelissa setosa, L. thoracites, Peridium longispinum, and Octactis octonaria), associated with the Gulf of California Water prevailed in episodic intervals during the late Pleistocene and the Holocene, suggesting mixed-water species. Due to an increase in evaporation processes in the gulf caused by the strength of NW winds and winter convection in the gulf, the dominance of this water mass may have occurred synchronously with the Monsoon System shift during the Holocene.
Published: 2023
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6. Early and middle Miocene ice sheet dynamics in the Ross Sea: Results from integrated core-log-seismic interpretation

Author: Pérez, Lara, De Santis, Laura, McKay, Robert M., Larter, Robert D., Ash, Jeanine, Bart, Phil J., Böhm, Gualtiero, Brancatelli, Giuseppe, Browne, Imogen, Colleoni, Florence, Dodd, Justin P., Geletti, Riccardo, Harwood, David M., Kuhn, Gerhard, Laberg, Jan Sverre, Leckie, R. Mark, Levy, Richard H., Marschalek, James, Mateo, Zenon, Naish, Timothy R., Sangiorgi, Francesca, Shevenell, Amelia E., Sorlien, Christopher C., van de Flierdt, Tina, International Ocean Discovery Program Expedition, 374 Scientists, Pérez, Lara, De Santis, Laura, McKay, Robert M., Larter, Robert D., Ash, Jeanine, Bart, Phil J., Böhm, Gualtiero, Brancatelli, Giuseppe, Browne, Imogen, Colleoni, Florence, Dodd, Justin P., Geletti, Riccardo, Harwood, David M., Kuhn, Gerhard, Laberg, Jan Sverre, Leckie, R. Mark, Levy, Richard H., Marschalek, James, Mateo, Zenon, Naish, Timothy R., Sangiorgi, Francesca, Shevenell, Amelia E., Sorlien, Christopher C., van de Flierdt, Tina, and International Ocean Discovery Program Expedition, 374 Scientists
Abstract: Oscillations in ice sheet extent during early and middle Miocene are intermittently preserved in the sedimentary record from the Antarctic continental shelf, with widespread erosion occurring during major ice sheet advances, and open marine deposition during times of ice sheet retreat. Data from seismic reflection surveys and drill sites from Deep Sea Drilling Project Leg 28 and International Ocean Discovery Program Expedition 374, located across the present-day middle continental shelf of the central Ross Sea (Antarctica), indicate the presence of expanded early to middle Miocene sedimentary sections. These include the Miocene climate optimum (MCO ca. 17−14.6 Ma) and the middle Miocene climate transition (MMCT ca. 14.6−13.9 Ma). Here, we correlate drill core records, wireline logs and reflection seismic data to elucidate the depositional architecture of the continental shelf and reconstruct the evolution and variability of dynamic ice sheets in the Ross Sea during the Miocene. Drill-site data are used to constrain seismic isopach maps that document the evolution of different ice sheets and ice caps which influenced sedimentary processes in the Ross Sea through the early to middle Miocene. In the early Miocene, periods of localized advance of the ice margin are revealed by the formation of thick sediment wedges prograding into the basins. At this time, morainal bank complexes are distinguished along the basin margins suggesting sediment supply derived from marine-terminating glaciers. During the MCO, biosiliceous-bearing sediments are regionally mapped within the depocenters of the major sedimentary basin across the Ross Sea, indicative of widespread open marine deposition with reduced glacimarine influence. At the MMCT, a distinct erosive surface is interpreted as representing large-scale marine-based ice sheet advance over most of the Ross Sea paleo-continental shelf. The regional mapping of the seismic stratigraphic architecture and its correlation to drilling da
Published: 2022

7. Early and middle Miocene ice sheet dynamics in the Ross Sea: Results from integrated core-log-seismic interpretation

Author: Pérez, Lara F., De Santis, Laura, McKay, Robert M., Larter, Robert D., Ash, Jeanine, Bart, Phil J., Böhm, Gualtiero, Brancatelli, Giuseppe, Browne, Imogen, Colleoni, Florence, Dodd, Justin P., Geletti, Riccardo, Harwood, David M., Kuhn, Gerhard, Sverre Laberg, Jan, Leckie, R. Mark, Levy, Richard H., Marschalek, James, Mateo, Zenon, Naish, Timothy R., Sangiorgi, Francesca, Shevenell, Amelia E., Sorlien, Christopher C., van de Flierdt, Tina, 374 Scientists, International Ocean Discovery Program Expedition, Pérez, Lara F., De Santis, Laura, McKay, Robert M., Larter, Robert D., Ash, Jeanine, Bart, Phil J., Böhm, Gualtiero, Brancatelli, Giuseppe, Browne, Imogen, Colleoni, Florence, Dodd, Justin P., Geletti, Riccardo, Harwood, David M., Kuhn, Gerhard, Sverre Laberg, Jan, Leckie, R. Mark, Levy, Richard H., Marschalek, James, Mateo, Zenon, Naish, Timothy R., Sangiorgi, Francesca, Shevenell, Amelia E., Sorlien, Christopher C., van de Flierdt, Tina, and 374 Scientists, International Ocean Discovery Program Expedition
Abstract: Oscillations in ice sheet extent during early and middle Miocene are intermittently preserved in the sedimentary record from the Antarctic continental shelf, with widespread erosion occurring during major ice sheet advances, and open marine deposition during times of ice sheet retreat. Data from seismic reflection surveys and drill sites from Deep Sea Drilling Project Leg 28 and International Ocean Discovery Program Expedition 374, located across the present-day middle continental shelf of the central Ross Sea (Antarctica), indicate the presence of expanded early to middle Miocene sedimentary sections. These include the Miocene climate optimum (MCO ca. 17−14.6 Ma) and the middle Miocene climate transition (MMCT ca. 14.6−13.9 Ma). Here, we correlate drill core records, wireline logs and reflection seismic data to elucidate the depositional architecture of the continental shelf and reconstruct the evolution and variability of dynamic ice sheets in the Ross Sea during the Miocene. Drill-site data are used to constrain seismic isopach maps that document the evolution of different ice sheets and ice caps which influenced sedimentary processes in the Ross Sea through the early to middle Miocene. In the early Miocene, periods of localized advance of the ice margin are revealed by the formation of thick sediment wedges prograding into the basins. At this time, morainal bank complexes are distinguished along the basin margins suggesting sediment supply derived from marine-terminating glaciers. During the MCO, biosiliceous-bearing sediments are regionally mapped within the depocenters of the major sedimentary basin across the Ross Sea, indicative of widespread open marine deposition with reduced glacimarine influence. At the MMCT, a distinct erosive surface is interpreted as representing large-scale marine-based ice sheet advance over most of the Ross Sea paleo-continental shelf. The regional mapping of the seismic stratigraphic architecture and its correlation to drilling da
Published: 2021

8. Multi-decadal trends in Antarctic sea-ice extent driven by ENSO–SAM over the last 2,000 years

Author: European Research Council, European Commission, Agence Nationale de la Recherche (France), Japan Society for the Promotion of Science, International Ocean Discovery Program, Crosta, Xavier, Etourneau, Johan, Orme, Lisa C., Dalaiden, Quentin, Campagne, Philippine, Swingedouw, Didier, Goosse, Hugues, Massé, Guillaume, Miettinen, Arto, McKay, Robert M., Dunbar, Robert B., Escutia, Carlota, Ikehara, Minoru, European Research Council, European Commission, Agence Nationale de la Recherche (France), Japan Society for the Promotion of Science, International Ocean Discovery Program, Crosta, Xavier, Etourneau, Johan, Orme, Lisa C., Dalaiden, Quentin, Campagne, Philippine, Swingedouw, Didier, Goosse, Hugues, Massé, Guillaume, Miettinen, Arto, McKay, Robert M., Dunbar, Robert B., Escutia, Carlota, and Ikehara, Minoru
Abstract: Antarctic sea ice has paradoxically become more extensive over the past four decades despite a warming climate. The regional expression of this trend has been linked to changes in vertical redistribution of ocean heat and large-scale wind-field shifts. However, the short length of modern observations has hindered attempts to attribute this trend to anthropogenic forcing or natural variability. Here, we present two new decadal-resolution records of sea ice and sea surface temperatures that document pervasive regional climate heterogeneity in Indian Antarctic sea-ice cover over the last 2,000 years. Data assimilation of our marine records in a climate model suggests that the reconstructed dichotomous regional conditions were driven by the multi-decadal variability of the El Niño Southern Oscillation and Southern Annular Mode (SAM). For example, during an El Niño/SAM– combination, the northward sea-ice transport was reduced while heat advection from the subtropics to the Southern Ocean increased, which resulted in reduced sea-ice extent in the Indian sector as sea ice was compacted along the Antarctic coast. Our results therefore indicate that natural variability is large in the Southern Ocean and suggest that it has played a crucial role in the recent sea-ice trends and their decadal variability in this region.
Published: 2021

9. A Plate Too Far: Lessons Learned and Insight Gained from scientific and operational achievements during IODP Expedition 358 in the Nankai Trough

Author: Adam Wspanialy, Sean Toczko, Nobu Eguchi, Lena Maeda, Kan Aoike, Tomo Saruhashi, Takehiro Hirose, Matt Ikari, Kyuichi Kanagawa, Gaku Kimura, Masataka Kinoshita, Hiroko Kitajima, Demian Saffer, Harold Tobin, Asuka Yamaguchi, and International Ocean Discovery Program Exp 358 Scientists
Subjects: Nankai trough, Geology, Seismology
Abstract: IODP Expedition 358 planned to access and sample the subducting plate boundary at the Nankai Trough, Japan, and commenced on 7 October 2018, and ended on 31 March 2019, marking the ultimate stage of the NanTroSEIZE project. The goal was to drill down to the plate boundary fault, about 5 km below the ocean floor, where >8M earthquakes occur regularly at every 100–150 years. The successful completion would have represented the deepest borehole in the history of scientific ocean drilling and ultimately greatly deepen our understanding about fault mechanics, earthquake inception and tsunami generation processes.The IODP Expedition 358 intended to access the plate boundary fault zone system through deepening the previously drilled and suspended C0002P hole. The original operational objective of the Exp 358 was to reach a total depth of 7267.5 mbrt (+/- 5200 mbsf) in 4 drilled sections. Previous major riser drilling efforts during the IODP Expeditions 338 and 348 advanced the main riser hole at Site C0002 (Hole C0002F/N/P) to 3058.5 mbsf meters below sea floor (mbsf). Extensive downhole logging data and limited intervals of core were collected during those expeditions.Due to the nature of the drilling operation and the anticipated challenges ahead, JAMSTEC adopted oil & gas industry drilling standards and performed two detailed Drilling Well on Paper (DWOP) workshops as part of the very rigorous preparatory stage. Great deal of time was spent on selecting new and state-of-the-art drilling/circulating techniques, logging tools, bits and drilling fluid formulation including a new mud sealant additive “FracSeal” to make sure borehole integrity issues can be minimized as much as possible. Drilling stages seen implementation of a novel concept of near real-time geomechanics to continuously monitor and assess borehole integrity.The challenges born from side-tracking near the bottom of the previously drilled Hole C0002P (2014 Exp. 348), proved greater than the multi-disciplinary teams expected and the overall objectives set for Exp.358 were not achieved. Nevertheless, despite the significant problems seen during several attempts, the hole was deepened 204 m. This is a minor success and it is believed, once away from the highly damaged area of the C0002P hole, drilling can produce a high-integrity hole following excellent communication and recommendations between drilling and scientific teams during complex drilling operations, especially in complex environments such as the Nankai Accretionary Prism.Despite not achieving the ultimate goal of the expedition, the implemented industry drilling standards, real-time surveillance system, real time geomechanics, improved and strict communication protocols, and integrating both scientific and drilling teams have demonstrated their value and should become standard practice during future IODP/ICDP operations.
Published: 2020
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10. A Plate Too Far: Lessons Learned and Insight Gained from scientific and operational achievements during IODP Expedition 358 in the Nankai Trough.

Author: Wspanialy, Adam, primary, Toczko, Sean, additional, Eguchi, Nobu, additional, Maeda, Lena, additional, Aoike, Kan, additional, Saruhashi, Tomo, additional, Hirose, Takehiro, additional, Ikari, Matt, additional, Kanagawa, Kyuichi, additional, Kimura, Gaku, additional, Kinoshita, Masataka, additional, Kitajima, Hiroko, additional, Saffer, Demian, additional, Tobin, Harold, additional, Yamaguchi, Asuka, additional, and Exp 358 Scientists, International Ocean Discovery Program, additional
Published: 2020
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11. A New Seismic Stratigraphy in the Indian-Atlantic Ocean Gateway Resembles Major Paleo-Oceanographic Changes of the Last 7 Ma

Author: International Ocean Discovery Program, German Research Foundation, Gruetzner, Jens, Jiménez Espejo, Francisco J., Lathika, Nambiyathodi, Uenzelmann Neben, Gabriele, Hall, Ian R., Hemming, S.R., LeVay, Leah J., International Ocean Discovery Program, German Research Foundation, Gruetzner, Jens, Jiménez Espejo, Francisco J., Lathika, Nambiyathodi, Uenzelmann Neben, Gabriele, Hall, Ian R., Hemming, S.R., and LeVay, Leah J.
Abstract: The exchange of water masses between the Indian Ocean and the Atlantic constitutes an integral interocean link in the global thermohaline circulation. Long-term changes in deep water flow have been studied using seismic reflection profiles but the seismic stratigraphy was poorly constrained and not resolved for the time period from the late Miocene onward. Here we present results from International Ocean Discovery Program Site U1475 (Agulhas Plateau) located over a sediment drift proximal to the entrance of North Atlantic Deep Water into the Southern Ocean and South Indian Ocean. Site U1475 comprises a complete carbonate-rich stratigraphic section of the last ~7 Ma that provides an archive of climate-induced variations in ocean circulation. Six marker reflectors occurring in the upper 300 m of the drift are identified here for the first time. The formation of these reflectors is mainly due to density changes that are mostly caused by changes in biogenic versus terrigenous sediment deposition. Synthetic seismograms allow age assignments for the horizons based on biostratigraphy and magnetostratigraphy. Prominent reflectors are related to late Pleistocene glacial/interglacial variability, the middle and early Pleistocene transitions, and the onset of the northern hemisphere glaciation. A peculiar early Pliocene interval (~5.3–4.0 Ma) bounded by two reflectors is characterized by fourfold elevated sedimentation rates (>10 cm/kyr) and the occurrence of sediment waves. We argue that this enhanced sediment transport to the Agulhas Plateau was caused by a reorganization of the bottom current circulation pattern due to maximized inflow of North Atlantic Deep Water.
Published: 2019

12. Southern Ocean warming and Wilkes Land ice sheet retreat during the mid-Miocene

Author: International Ocean Discovery Program, National Science Foundation (US), German Research Foundation, Ministerio de Economía y Competitividad (España), European Commission, Sangiorgi, Francesca, Bijl, Peter K., Passchier, Sandra, Schouten, Stefan, McKay, Robert M., Cody, Rosemary D., Pross, Jörg, van de Flierdt, Tina, Bohaty, Steven M., Levy, Richard, Williams, Trevor G., Escutia, Carlota, Brinkhuis, Henk, International Ocean Discovery Program, National Science Foundation (US), German Research Foundation, Ministerio de Economía y Competitividad (España), European Commission, Sangiorgi, Francesca, Bijl, Peter K., Passchier, Sandra, Schouten, Stefan, McKay, Robert M., Cody, Rosemary D., Pross, Jörg, van de Flierdt, Tina, Bohaty, Steven M., Levy, Richard, Williams, Trevor G., Escutia, Carlota, and Brinkhuis, Henk
Abstract: Observations and model experiments highlight the importance of ocean heat in forcing ice sheet retreat during the present and geological past, but past ocean temperature data are virtually missing in ice sheet proximal locations. Here we document paleoceanographic conditions and the (in)stability of the Wilkes Land subglacial basin (East Antarctica) during the mid-Miocene (~17-13.4 million years ago) by studying sediment cores from offshore Adélie Coast. Inland retreat of the ice sheet, temperate vegetation, and warm oligotrophic waters characterise the mid-Miocene Climatic Optimum (MCO; 17-14.8 Ma). After the MCO, expansion of a marine-based ice sheet occurs, but remains sensitive to melting upon episodic warm water incursions. Our results suggest that the mid-Miocene latitudinal temperature gradient across the Southern Ocean never resembled that of the present day. We demonstrate that a strong coupling of oceanic climate and Antarctic continental conditions existed and that the East Antarctic subglacial basins were highly sensitive to ocean warming.
Published: 2018

13. Heat flow and thermal regime in the Guaymas Basin, Gulf of California: Estimates of conductive and advective heat transport

Author: Neumann, Florian, Negrete-Aranda, Raquel, Harris, Robert, Contreras, Juan, Galerne, Christophe, Peña-Salinas, Manet, Spelz, Ronald, Teske, Andreas, Lizarralde, Daniel, Höfig, Tobias, Aiello, Ivano, Ash, Janine, Bojanova, Diana, Buatier, Martine, Edgcomb, Virginia, Gontharet, Swanne, Heuer, Verena, Jiang, Shijun, Kars, Myriam A.C., Kim, Ji‐hoon, Koornneef, Louise M.T., Marsaglia, Kathleen, Meyer, Nicolette, Morono, Yuki, Pastor, Lucie, Pérez Cruz, Ligia, Ran, Lihua, Riboulleau, Armelle, Sarao, John, Schubert, Florian, Singh, S. Khogenkumar, Stock, Joann, Toffin, Laurent M.A.A., Xie, Wei, Yamanaka, Toshiro, Zhuang, Guangchao, Centro de Investigacion Cientifica y de Education Superior de Ensenada [Mexico] (CICESE), College of Earth, Ocean and Atmospheric Sciences [Corvallis] (CEOAS), Oregon State University (OSU), Universität Bremen, Universidad Autónoma de Baja California (UABC), University of North Carolina [Chapel Hill] (UNC), University of North Carolina System (UNC), Woods Hole Oceanographic Institution (WHOI), International Ocean Discovery Program, Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Cycles biogéochimiques marins : processus et perturbations (CYBIOM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Center for Marine Environmental Sciences [Bremen] (MARUM), Geological Sciences, Florida State University [Tallahassee] (FSU), Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Laboratoire Environnement Profond (LEP), Etudes des Ecosystèmes Profonds (EEP), and Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)
Subjects: Guyamas Basin, [SDE]Environmental Sciences, IODP Expedition 385, Geology, Heat Flow, Heat Transfer
Abstract: Heat flow is estimated at eight sites drilled during the International Ocean Discovery Program Expedition 385 into the Guaymas Basin, Gulf of California. The expedition sought to understand the thermal regime of the basin and heat transfer between off-axis sills intruding the organic-rich sediments of the Guaymas Basin, and the basin floor. The distinct sedimentation rates, active tectonics, and magmatism makes the basin interesting for scientific discoveries. Results show sedimentation corrected heat flow values range 119-221 mW/m2 in the basin and 257-1003 mW/m2 at the site of a young sill intrusion, denominated Ringvent. Thermal analysis shows that heat in the Guaymas Basin is being dissipated by conduction for plate ages >0.2 Ma, whereas younger plate ages are in a state of transient cooling by both conduction and advection. Drilling sites show that Ringvent is an active sill being cooled down slowly by circulating fluids with discharge velocities 10–200 mm/yr. Possible recharge sites are located ~1 km away from the sill's border. Modeling of the heat output at Ringvent indicates a sill thickness of ~240 m. A simple order-of-magnitude model predicts that relatively small amounts of magma are needed to account for the elevated heat flow in non-volcanic, sediment-filled rifts like the central and northern Gulf of California in which heating of the upper crust is achieved via advection by sill emplacement and hydrothermal circulation. Multiple timescales of cooling control the crustal, chemical and biological evolution of the Guaymas Basin. Here we recognize at least four timescales: the time interval between intrusions (~103 yr), the thermal relaxation time of sills (~104 yr), the characteristic cooling time of the sediments (~105 yr), and the cooling of the entire crust at geologic timescales.
Published: 2023
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14. Magma-sediment mingling processes, control and longevity of related hydrothermal systems – Implications for the Earth’s Carbon-, Plate-, Life-Cycles (IODP Exp 385, Guaymas Basin, Gulf of California)

Author: Galerne, Christophe, Bach, Wolfgang, Berndt, Christian, Schwark, Lorenz, Höfig, Tobias, Buatier, Martine, Cheviet, Alban, Kahl, Wolf-Achim, Hasenclever, Jörg, Lizarralde, Daniel, Stockhausen, Martin, Wiggers, Christin, Karstens, Jens, Monien, Patrick, Teske, Andreas, Aiello, Ivano W., Ash, Jeanine L., Bojanova, Diana P., Edgcomb, Virginia P., Gontharet, Swanne, Heuer, Verena B., Jiang, Shijun, Kars, Myriam A.C., Singh, S. Khogenkumar, Kim, Ji-Hoon, Koornneef, Louise M.T., Marsaglia, Kathleen M., Meyer, Nicolette R., Morono, Yuki, Negrete-Aranda, Raquel, Neumann, Florian, Pastor, Lucie C., Pena-Salinas, Manet E., Cruz, Ligia L. Perez, Ran, Lihua, Riboulleau, Armelle, Sarao, John A., Schubert, Florian, Stock, Joann M., Toffin, Laurent M.A.A., Xie, Wei, Yamanaka, Toshiro, Zhuang, Guangchao, Ortega, Rodrigo Perez, Geoscience Department and MARUM, University of Bremen, Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Institute of Geosciences [Kiel], Christian-Albrechts-Universität zu Kiel (CAU), Curtin University [Perth], Planning and Transport Research Centre (PATREC), International Ocean Discovery Program, Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC), University of Bremen, University of Hamburg, Woods Hole Oceanographic Institution (WHOI), University of North Carolina [Chapel Hill] (UNC), University of North Carolina System (UNC), Cycles biogéochimiques marins : processus et perturbations (CYBIOM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Geological Sciences, Florida State University [Tallahassee] (FSU), Kyung Hee University (KHU), Kochi Institute for Core Sample Research, and Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
Subjects: [SDE]Environmental Sciences
Abstract: Magma-sediment mingling occurring in shallow porous sediments is mainly investigated through field observations of old exhumed rift basins. During the IODP Expedition 385 we have drilled through the shallow sills emplaced in the active rift of the Guaymas Basin, Gulf of California. The results of this expedition enable a pioneer study of the impact of recent magma-sediment mingling processes leading to peperite formation. Furthermore, it provides a present-day geological context to investigate and quantify the impact of this mingling process on the element cycles in subsurface sediments, and temporal evolution of the microbial habitat associated with epithermal hydrothermal fluid circulation. Our approach of exploring magma-sediment mingling processes includes laboratory experiments, numerical modelling, and identification of specific field analogues in addition to petrological and geochemical constraints.Using these modern techniques, we review here the discoveries made during the IODP Expedition 385 and present preliminary results from our post-cruise research from the perspective of the peperite formation. We report here petrographic and geochemical evidence of magma sediment hybridization indicative of an intense mingling process inferred to occur during the emplacement phase. The rheology of the soft, unconsolidated sediment controls and explains the various intrusion shapes and dimensions. Numerical simulation results indicate that heat dissipation in this context is much less efficient, which in turn considerably decreases the amount of thermogenic gas mobilized through thermal cracking in the contact aureole of sills. Additionally, we observe that hydrothermal pipe systems established during the cooling phase of sill emplacement can remain active at moderate- to low-temperature state after the heat of the sill has vanished. Using 2D seismic information and IODP drilling results, we were able to reconstruct the 3D structure of the sill at depth. It is funnel-shaped and roots in a depth where geothermal fluids can ascend from. The temperature found at these depths is consistent with the background geothermal gradient, suggesting that the large heat flow anomaly found at Hole U1548C is the mere expression of the active hydrothermal circulation fuelled by deeply sourced geothermal fluids.These potentially long-lasting hydrothermal systems provide preferable temperature and energetic conditions for microbial activity to thrive, with mildly degraded petroleum components from below and water recharge from above. Moreover, evidence indicates that the sill at Site U1547 is non-unique at the scale of the Guaymas Basin. How many of these catabolic reactors form at the early rifting phase? Can this process perhaps trigger peaks in subsurface biomass production associated with new continental margin formation? Our research heralds the dawn of a new paradigm. We suggest that in the context of a nascent ocean, sill emplacement in the first 500 m of sediments may power life instead of suppressing it.
Published: 2022
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15. Diagenetic carbonates from deep sub-seafloor organic-rich sediments influenced by magmatic sill intrusions (IODP Exp 385-Guaymas Basin, Gulf of California)

Author: Gontharet, Swanne, Pierre, Catherine, Pelleter, Ewan, Caquineau, Sandrine, Boudouma, Omar, Demange, Jérôme, Teske, Andreas, Lizarralde, Daniel, Höfig, Tobias, Cycles biogéochimiques marins : processus et perturbations (CYBIOM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Géosciences Marines (GM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut des Sciences de la Terre de Paris (iSTeP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of North Carolina [Chapel Hill] (UNC), University of North Carolina System (UNC), Woods Hole Oceanographic Institution (WHOI), International Ocean Discovery Program, and EGU
Subjects: [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]
Abstract: During the International Ocean Discovery Program (IODP) Expedition 385, diagenetic carbonates were recovered at different depths (from 10 to 534 mbsf) in six drilling sites (U1545, U1546, U1547, U1548, U1550 and U1552) distributed from the northern spreading segment of the Guaymas Basin (Gulf of California) to ~52 km away from the axial graben. As this basin is a site of active sea floor spreading, hemipelagic diatomaceous and organic-rich sediments rapidly accumulating at all these drilling sites are influenced by magmatic intrusions, at depths greater than 90 mbsf. The geothermal gradient observed ranges from 135 °C/km to 682 °C/km. Except in sites U1547 and U1548, both located close to a circular hydrothermal mound (called Ringvent), sills are in thermal equilibrium with the surrounding sediments. Carbonate samples (over fifty) collected during this expedition are composed of fine-grained micritic sediments and weakly to strongly lithified carbonate concretions. The petrographic observations and XRD analyses show that stoichiometric dolomite is the dominant authigenic carbonate phase, with minor contribution of Fe-rich dolomite, and low- to high-Mg calcite. Centimeter-sized concretions composed of ankerite and Mg-calcite also occur in the sediments collected from the northern axial graben (site U1550) and a site with subsurface gas hydrates (U1552), respectively. Other authigenic minerals are often associated with these carbonates including pyrite, barite, anhydrite, zeolites and crystalline opal (opal-CT). The carbon isotopic compositions of the bulk carbonate from these samples exhibit large variations ranging from -28.9 to +12.0‰ VPDB. Very low d 13C values, only measured in a centimetre-seized concretion associated with cold methane seepage (site U1552), indicate that the bicarbonate used for carbonate precipitation is derived from anaerobic oxidation of methane (AOM) coupled with bacterial sulfate reduction (BSR). The very high d13C values of diagenetic carbonates indicate the use of biogenic 13C-rich CO2 reservoirs related to active methanogenesis or other autotrophic microbial pathways. The oxygen isotopic compositions of these carbonates cover a large range from -5.3 to +4.0‰ VPDB. The decreasing d18O values with increasing depth reflect the effect of high geothermal gradients due to the close proximity of magmatic sills.
Published: 2022
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16. Guaymas Basin Tectonics and Biosphere

Author: Teske, A., Lizarralde, D., Höfig, T.W., Aiello, Ivano W., Ash, Jeanine L., Bojanova, Diana P., Buatier, Martine D., Edgcomb, Virginia P., Galerne, Christophe Y., Gontharet, Swanne, Heuer, Verena B., Jiang, Shijun, Kars, Myriam A.C., Singh, S. Khogenkumar, Kim, Ji-Hoon, Koornneef, Louise M.T., Marsaglia, Kathleen M., Meyer, Nicolette R., Morono, Yuki, Negrete-Aranda, Raquel, Neumann, Florian, Pastor, Lucie C., Pena-Salinas, Manet E., Perez-Cruz, Ligia L., Ran, Lihua, Riboulleau, Armelle, Sarao, John A., Schubert, Florian, Stock, Joann M., Toffin, Laurent M.A.A., Xie, Wei, Yamanaka, Toshiro, Zhuang, Guangchao, Ortega, Rodrigo Perez, European Infective Endocarditis Registry (Euro-Endo), Woods Hole Oceanographic Institution (WHOI), International Ocean Discovery Program, Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Cycles biogéochimiques marins : processus et perturbations (CYBIOM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Geological Sciences, Florida State University [Tallahassee] (FSU), Kyung Hee University (KHU), Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Key Laboratory of Marine Ecosystem Dynamics, Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord]), Institute of Molecular Medicine and Cell Research (ZBMZ), University of Freiburg [Freiburg], Seismological Laboratory, California Institute of Technology (CALTECH), and Tokyo University of Marine Science and Technology (TUMSAT)
Subjects: Tectonics, Guaymas Basin, [SDE]Environmental Sciences, Geochemistry, Biosphere, Geology
Abstract: A complete set of the logging data collected during the expedition is available at http://mlp.ldeo.columbia.edu/logdb/scientific_ocean_drilling. If you have problems downloading the data, wish to receive additional logging data, or have questions regarding the data, please contact Database Administrator, Bore
Published: 2021
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17. Site U1539

Author: G. Winckler, F. Lamy, C.A. Alvarez Zarikian, H.W. Arz, C. Basak, A. Brombacher, O.M. Esper, J.R. Farmer, J. Gottschalk, L.C. Herbert, S. Iwasaki, V.J. Lawson, L. Lembke-Jene, L. Lo, E. Malinverno, E. Michel, J.L. Middleton, S. Moretti, C.M. Moy, A.C. Ravelo, C.R. Riesselman, M. Saavedra-Pellitero, I. Seo, R.K. Singh, R.A. Smith, A.L. Souza, J.S. Stoner, I.M. Venancio, S. Wan, X. Zhao, N. Foucher McColl, Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Alfred Wegener Institute for Polar and Marine Research (AWI), International Ocean Discovery Program, Leibniz Institute for Baltic Sea Research Warnemünde (IOW), University of Delaware [Newark], National Oceanography Centre (NOC), Department of Geosciences [Princeton], Princeton University, School of Marine and Atmospheric Sciences [Stony Brook] (SoMAS), Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers), National Taïwan University (NTU), Università degli Studi di Milano = University of Milan (UNIMI), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Paléocéanographie (PALEOCEAN), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Chemistry (MPIC), Max-Planck-Gesellschaft, University of Otago [Dunedin, Nouvelle-Zélande], University of California [Santa Cruz] (UC Santa Cruz), and University of California (UC)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, International Ocean Discovery Program, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, IODP, JOIDES Resolution, Expedition 383
Abstract: International audience; This work is distributed under the Creative Commons Attribution 4.0 International (CC BY 4.0) license. Contents 1 Background and objectives 4 Operations 7 Sedimentology 18 Biostratigraphy 32 Paleomagnetism 33 Geochemistry 38 Physical properties 42 Downhole measurements 43 Stratigraphic correlation 52 References
Published: 2021
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18. Assessment of C, N and Si isotopes as tracers of past ocean nutrient and carbon cycling

Author: Farmer, J.R., Hertzberg, J.E., Cardinal, Damien, Fietz, Susanne, Hendry, K. R., Jaccard, Samuel L., Paytan, Adina, Rafter, Patrick, Ren, H., Somes, Christoper J., Sutton, Jill N., Calvo, Eva María, GEOTRACES-PAGES Biological Productivity Working Group Members, National Science Foundation (US), Swiss Academy of Sciences, Max Planck Society, Princeton University, Exxon Mobil Corporation, Agencia Estatal de Investigación (España), Department of Geosciences [Princeton], International Ocean Discovery Program, Cycles biogéochimiques marins : processus et perturbations (CYBIOM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Department of Earth Sciences [Stellenbosch], Stellenbosch University, School of Earth Sciences [Bristol], University of Bristol [Bristol], Oeschger Centre for Climate Change Research (OCCR), University of Bern, University of California [Santa Cruz] (UC Santa Cruz), University of California (UC), Department of Earth System Science [Irvine] (ESS), University of California [Irvine] (UC Irvine), University of California (UC)-University of California (UC), National Taiwan University [Taiwan] (NTU), Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), University of California [Santa Cruz] (UCSC), University of California, University of California [Irvine] (UCI), University of California-University of California, and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Atmospheric Science, Nutrient cycle, 010504 meteorology & atmospheric sciences, chemistry.chemical_element, stable isotopes, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 010502 geochemistry & geophysics, 01 natural sciences, nitrogen, Carbon cycle, Paleoceanography, Phytoplankton, marine chemistry, Environmental Chemistry, 14. Life underwater, 550 Earth sciences & geology, 0105 earth and related environmental sciences, General Environmental Science, Global and Planetary Change, Carbon dioxide in Earth's atmosphere, Stable isotope ratio, carbon, silicon, Oceanography, chemistry, [SDU]Sciences of the Universe [physics], 13. Climate action, Isotopes of carbon, paleoceanography, Environmental science, Carbon
Abstract: 28 pages, 6 figures, 1 box, 1 appendix.-- Data Availability Statement: Data sets presented in this research are available via the following repositories and study (listed by Figure): Figures 3 and 4: (1)δ13CDIC:(a) CLIVAR P16S (Feely et al., 2008) from GLODAPv2.2020 database (Olsen et al., 2020): https://www.glodap.info/index.php/merged-and-adjusted-data-product/. (b) GEOTRACES GA03 (Quay & Wu, 2015) and GP16 (P. Quay, unpublished data) from GEOTRACES IDP2017 (Schlitzer et al., 2018): https://www.bodc.ac.uk/geotraces/data/idp2017/. (2) δ15Nnitrate:(a) CLIVAR P16S (Rafter et al., 2013) from BCO-DMO: https://www.bco-dmo.org/dataset/651722. (b) GEOTRACES GA03 (Marconi et al., 2015) and GP16 (Peters et al., 2018) from GEOTRACES IDP2017 (Schlitzer et al., 2018): https://www.bodc.ac.uk/geotraces/data/idp2017/. (3) δ30Si: GEOTRACES GA03 (Brzezinski & Jones, 2015) and GIPY04 (Fripiat et al., 2012) from GEOTRACES IDP2017 (Schlitzer et al., 2018): https://www.bodc.ac.uk/geotraces/data/idp2017/. (4) Figure 4a POC Flux (DeVries & Weber, 2017): SIMPLE-TRIM Output from https://tdevries.eri.ucsb.edu/models-and-data-products/. Figure 5: (a) Antarctic CO2 composite: https://www.ncdc.noaa.gov/paleo-search/study/17975. (b) ∆δ13Cthermocline-deep from Ziegler et al. (2013) supporting information: https://www.nature.com/articles/ngeo1782; ∆δ13Cepifaunal-infaunal (Hoogakker et al., 2018): https://doi.pangaea.de/10.1594/PANGAEA.891185. (c) SAZ FB-δ15N (Martínez-García et al., 2014): https://www.ncdc.noaa.gov/paleo/study/18318; AZ DB-δ15N (Studer et al., 2015): https://doi.pangaea.de/10.1594/PANGAEA.848271. (d) SAZ Fe flux (Martínez-García et al., 2014): https://www.ncdc.noaa.gov/paleo/study/18318. (e) AZ diatom δ30Si (Robinson et al., 2014): https:// www.ncdc.noaa.gov/paleo/study/17917. Figure 6: (a) and (b) Benthic foraminifera δ18O and δ13C (Zachos et al., 2001): https:// www.ncdc.noaa.gov/paleo/study/8674. (c) FB-δ15N from Kast et al. (2019) supporting information data: https://science.sciencemag.org/content/suppl/2019/04/24/364.6438.386.DC1. (d) and (e) Diatom, sponge, and radiolarian δ30Si in Egan et al. (2013) supporting information: https://www.sciencedirect.com/science/article/pii/S0012821X13002185, Fontorbe et al. (2016) supporting information: https://www.sciencedirect.com/science/article/pii/S0012821X16304265, and Fontorbe et al. (2017) supporting information: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017PA003090, Biological productivity in the ocean directly influences the partitioning of carbon between the atmosphere and ocean interior. Through this carbon cycle feedback, changing ocean productivity has long been hypothesized as a key pathway for modulating past atmospheric carbon dioxide levels and hence global climate. Because phytoplankton preferentially assimilate the light isotopes of carbon and the major nutrients nitrate and silicic acid, stable isotopes of carbon (C), nitrogen (N), and silicon (Si) in seawater and marine sediments can inform on ocean carbon and nutrient cycling, and by extension the relationship with biological productivity and global climate. Here, we compile water column C, N, and Si stable isotopes from GEOTRACES-era data in four key ocean regions to review geochemical proxies of oceanic carbon and nutrient cycling based on the C, N, and Si isotopic composition of marine sediments. External sources and sinks as well as internal cycling (including assimilation, particulate matter export, and regeneration) are discussed as likely drivers of observed C, N, and Si isotope distributions in the ocean. The potential for C, N, and Si isotope measurements in sedimentary archives to record aspects of past ocean C and nutrient cycling is evaluated, along with key uncertainties and limitations associated with each proxy. Constraints on ocean C and nutrient cycling during late Quaternary glacial-interglacial cycles and over the Cenozoic are examined. This review highlights opportunities for future research using multielement stable isotope proxy applications and emphasizes the importance of such applications to reconstructing past changes in the oceans and climate system, This workshop was funded by the United States National Science Foundation (NSF) through the GEOTRACES program, the international Past Global Changes (PAGES) project, which in turn received support from the Swiss Academy of Sciences and NSF, and the French national program LEFE (Les Enveloppes Fluides et l'Environnement). [...] This study was supported by PAGES, LEFE, and GEOTRACES through NSF. J. R. Farmer acknowledges support from the Max Planck Society, the Tuttle Fund of the Department of Geosciences of Princeton University, the Grand Challenges Program of the Princeton Environmental Institute, and through Exxon Mobil via the Andlinger Center for Energy and the Environment of Princeton University. Open access funding enabled and organized by Projekt DEAL. [...] With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)
Published: 2021
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19. Magma plumbing system and associated hydrothermal vents in the Guaymas Basin - geometry and implications

Author: Galerne, Christophe, Lizarralde, Daniel, Berndt, Christian, Neumann, Florian, Höfig, Tobias, Stock, Joann, Peña-Salinas, Manet, Negrete-Aranda, Raquel, Teske, Andreas, Aiello, Ivano W., Ash, Jeanine L., Bojanova, Diana P., Buatier, Martine D., Edgcomb, Virginia P., Gontharet, Swanne, Heuer, Verena B., Jiang, Shijun, Kars, Myriam A.C., Singh, S. Khogenkumar, Kim, Ji-Hoon, Koornneef, Louise M.T., Marsaglia, Kathleen M., Meyer, Nicolette R., Morono, Yuki, Pastor, Lucie C., Cruz, Ligia L. Perez, Ran, Lihua, Riboulleau, Armelle, Sarao, John, Schubert, Florian, Toffin, Laurent M.A.A., Xie, Wei, Yamanaka, Toshiro, Zhuang, Guangchao, Ortega, Rodrigo Perez, Woods Hole Oceanographic Institution (WHOI), Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), International Ocean Discovery Program, Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Cycles biogéochimiques marins : processus et perturbations (CYBIOM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Geological Sciences, Florida State University [Tallahassee] (FSU), Kyung Hee University (KHU), Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Key Laboratory of Marine Ecosystem Dynamics, Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), and Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord])
Subjects: Guaymas Basin, Magma, [SDE]Environmental Sciences, Geochemistry, 14. Life underwater, Geology, Hydrothermal vent
Abstract: We document the geometry of a massive sill at the root of an approximately 20-m high and 800 m-wide ring of hydrothermal formations, termed Ringvent, located 28.5 km off-axis on the northwestern flanking regions of the actively rifting Guaymas Basin (Gulf of California). Using petrophysical data collected during the IODP Expedition 385 and processed 2D seismic profiles, we present evidence on the mechanics of sill emplacement and how the related hydrothermal vent conduits were constructed. The currently active moderate-temperature hydrothermal vent field indicates that, despite being cold and crystallized, the magma plumbing system, is tapping into a deeper geothermal source of the basin. The vent system roots at the vertical end of the magma plumbing system with the top of the sill located at a depth range of 80 to 150 m below the seafloor. Our research aims at constraining how far deep the geothermal fluids are coming from, and identifying how close the hydrothermal system is from a steady-state condition, to draw implications for how frequently such a system may arise in nascent ocean basins.
Published: 2021
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20. Expedition 383 summary

Author: Elisa Malinverno, E. Michel, N. Foucher McColl, J. Gottschalk, J.S. Stoner, Mariem Saavedra-Pellitero, V.J. Lawson, L. Lo, S. Moretti, Shiming Wan, Shinya Iwasaki, L.C. Herbert, Gisela Winckler, Igor Martins Venancio, C. A. Alvarez Zarikian, Xiaojian Zhao, Ana Christina Ravelo, C. Basak, Jennifer L. Middleton, Frank Lamy, Christopher M. Moy, A.L. Souza, R.A. Smith, Jesse Farmer, L. Lembke-Jene, Anieke Brombacher, Christina R. Riesselman, Helge W Arz, Oliver Esper, I. Seo, Raj K. Singh, Lamy, F., Winckler, G., Alvarez Zarikian, C.A., and the Expedition 383 Scientists, Winckler, G, Lamy, F, Alvarez Zarikian, C, Arz, H, Basak, C, Brombacher, A, Esper, O, Farmer, J, Gottschalk, J, Herbert, L, Iwasaki, S, Lawson, V, Lembke-Jene, L, Lo, L, Malinverno, E, Michel, E, Middleton, J, Moretti, S, Moy, C, Ravelo, A, Riesselman, C, Saavedra-Pellitero, M, Seo, I, Singh, R, Smith, R, Souza, A, Stoner, J, Venancio, I, Wan, S, Zhao, X, Foucher McColl, N, Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Alfred Wegener Institute for Polar and Marine Research (AWI), International Ocean Discovery Program, Leibniz Institute for Baltic Sea Research Warnemünde (IOW), University of Delaware [Newark], National Oceanography Centre (NOC), Department of Geosciences [Princeton], Princeton University, School of Marine and Atmospheric Sciences [Stony Brook] (SoMAS), Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers), National Taïwan University (NTU), Università degli Studi di Milano = University of Milan (UNIMI), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Paléocéanographie (PALEOCEAN), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Chemistry (MPIC), Max-Planck-Gesellschaft, University of Otago [Dunedin, Nouvelle-Zélande], University of California [Santa Cruz] (UC Santa Cruz), University of California (UC), University of Birmingham [Birmingham], Korea Institute of Ocean Science and Technology (KIOST), Indian Institute of Technology Bhubaneshwar, University of Massachusetts [Amherst] (UMass Amherst), University of Massachusetts System (UMASS), State University of Rio de Janeiro, Oregon State University (OSU), Center for Weather Forecasting and Climate Studies [São Paulo] (CPTEC), Instituto Nacional de Pesquisas Espaciais (INPE), Chinese Academy of Sciences [Beijing] (CAS), National Insitute of Polar Research [Japan], National Institute of Polar Research [Tokyo] (NiPR), and Universidad Andrés Bello [Santiago] (UNAB)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, International Ocean Discovery Program, GEO/02 - GEOLOGIA STRATIGRAFICA E SEDIMENTOLOGICA, International Ocean Discovery Program, IODP, JOIDES Resolution, Expedition 383, Dynamics of the Pacific Antarctic Circumpolar Current, Site U1539, Site U1540, Site U1541, Site U1542, Site U1543, Site U1544, Southern Ocean, South Pacific, Chilean margin, paleoceanography, Antarctic Circumpolar Current, oceanic fronts, Circumpolar Deep Water, Antarctic Intermediate Water, marine carbon cycle, dust, biological productivity, iron fertilization, southern westerly winds, Patagonian ice sheet, West Antarctic ice sheet, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, GEO/01 - PALEONTOLOGIA E PALEOECOLOGIA, ComputingMilieux_MISCELLANEOUS, Geology, IODP, JOIDES Resolution, Expedition 383
Abstract: The Antarctic Circumpolar Current (ACC), the world’s strongest zonal current system, connects all three major ocean basins of the global ocean and therefore integrates and responds to global climate variability. Its flow is largely driven by strong westerly winds and is constricted to its narrowest extent in the Drake Passage. Fresh and cold Pacific surface and intermediate water flowing through the Drake Passage (cold-water route) and warm Indian Ocean water masses flowing through the Agulhas region (warm-water route) are critical for the South Atlantic contribution to Meridional Overturning Circulation changes. Furthermore, physical and biological processes associated with the ACC affect the strength of the ocean carbon pump and therefore are critical to feedbacks linking atmospheric CO2 concentrations, ocean circulation, and climate/cryosphere on a global scale. In contrast to the Atlantic and Indian sectors of the ACC, and with the exception of drill cores from the Antarctic continental margin and off New Zealand, there are no deep-sea drilling paleoceanographic records from the Pacific sector of the ACC. To advance our understanding of Miocene to Holocene atmosphere-ocean-cryosphere dynamics in the Pacific and their implications for regional and global climate and atmospheric CO2, International Ocean Discovery Program Expedition 383 recovered sedimentary sequences at (1) three sites in the central South Pacific (CSP) (U1539, U1540, and U1541), (2) two sites at the Chilean margin (U1542 and U1544), and (3) one site from the pelagic eastern South Pacific (U1543) close to the entrance to the Drake Passage. Because of persistently stormy conditions and the resulting bad weather avoidance, we were not successful in recovering the originally planned Proposed Site CSP-3A in the Polar Frontal Zone of the CSP. The drilled sediments at Sites U1541 and U1543 reach back to the late Miocene, and those at Site U1540 reach back to the early Pliocene. High sedimentation rate sequences reaching back to the early Pleistocene (Site U1539) and the late Pleistocene (Sites U1542 and U1544) were recovered in both the CSP and at the Chilean margin. Taken together, the sites represent a depth transect from ~1100 m at Chilean margin Site U1542 to ~4070 m at CSP Site U1539 and allow investigation of changes in the vertical structure of the ACC, a key issue for understanding the role of the Southern Ocean in the global carbon cycle. The sites are located at latitudes and water depths where sediments will allow the application of a wide range of siliciclastic-, carbonate-, and opal-based proxies to address our objectives of reconstructing, with unprecedented stratigraphic detail, surface to deep-ocean variations and their relation to atmosphere and cryosphere changes.
Published: 2021
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21. Steady erosion rates in the Himalayas through late Cenozoic climatic changes

Author: Jérôme Lavé, Didier Bourlès, Christian France-Lanord, Georges Aumaître, Karim Keddadouche, Sebastien Jean Paul Lenard, Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), The samples were provided by IODP (International Ocean Discovery Program). We acknowledge the team of IODP Kochi Core Center for their assistance in sample collection, and the teams of CRPG (Centre de Recherches Pétrographiques et Géochimiques), SARM (Service d’Analyses des Roches et des Minéraux) and CEREGE (Centre de Recherche et d’Enseignement de Géosciences de l’Environnement) for their assistance in sample preparation and measurements. We thank A. Galy sharing some Sr-Nd data and providing data quality control. The 10 Be measurements were performed at the ASTER AMS national facility (Accélérateur pour les Sciences dela Terre, Environnement, Risques, at CEREGE, Aix en Provence), which is supported by the INSU/CNRS (Institut National des Sciences de l’Univers/Centre National dela Recherche Scientifique), the ANR (Agence Nationale de la Recherche) through the ‘Projets thématiques d’excellence’ programme for the ‘Equipements d’excellence’ ASTER-CEREGE action and IRD (Institut de Recherche pour le Développement). We acknowledge the support of a Université de Lorraine-CRPG PhD fellowship and a Université de Poitiers A.T.E.R. (Attaché Temporaire d’Enseignement et de Recherche) of S.L., the support of IODP France, and the support of the French Agence Nationale de la Recherche (ANR), under grant ANR-17-CE01-0018 (Himal Fan project). G.A., D.L.B. and K.K. are members of the ASTER team., Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Université de Lorraine-CRPG PhD fellowship, and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: Provenance, 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, Drainage basin, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 010502 geochemistry & geophysics, 01 natural sciences, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Glacial period, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, Cosmogenic nuclide, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, geography, geography.geographical_feature_category, Sediment, 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, BENGAL, Erosion, General Earth and Planetary Sciences, Physical geography, Bay, Geology
Abstract: Sediment accumulation rates and thermal trackers suggest a substantial and global increase in erosion rates over the past few million years. That increase is commonly associated with the impact of the Northern Hemisphere glaciation, but methodological biases have led researchers to debate this hypothesis. Here, we test whether Himalayan erosion rates increased by measuring beryllium-10 (10Be) in the sediment of the Bengal Bay seabed. Sediment originated from rocks that produced 10Be under the impact of cosmic rays during erosion near surface. Thus, the 10Be concentrations indicate erosion rates. The 10Be concentration of the Bengal Bay sediment depends on the contributions of the Ganga and Brahmaputra rivers. Their sediments have distinct 10Be concentrations because of distinct elevations and erosion in their drainage basins. Variable contributions could thus complicate erosion-rate calculation. We traced these contributions by a provenance study using the strontium (Sr) and neodymium (Nd) isotopic sediment compositions. Within uncertainties of ±30%, our reconstructed past erosion rates show no long-term increase for the past six million years. This stability suggests that climatic changes during the late Cenozoic have an undetectable impact on the erosion patterns in the Himalayas, at least on the ten thousand to million year timescales accounted for by our dataset. Long-term Himalayan erosion rates remained stable through the global climatic changes of the past six million years, according to the cosmogenic nuclide composition of terrestrial sediments recovered from the Bay of Bengal.
Published: 2020
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22. Mariana serpentinite mud volcanism exhumes subducted seamount materials: implications for the origin of life

Author: R.T. Kevorkian, Barbara A. Bekins, Jeffrey G. Ryan, Shino Suzuki, Kevin T. M. Johnson, Roy E. Price, Walter Kurz, P. Eickenbusch, Diva J. Amon, Rui Zhang, Elmar Albers, Shirley A. Pomponi, John W. Shervais, S.S. Mantovanelli, C. Geoffrey Wheat, Jianghong Deng, Deborah Glickson, R.M. Johnston, Baptiste Debret, Emanuelle Frery, Jung-Woo Park, Katsuyoshi Michibayashi, B. Walter, Patricia Fryer, Olivier Sissmann, K.K. Mullane, Christopher Kelley, Yanhui Dong, Vitor Magalhães, Yuji Ichiyama, Ken Takai, Trevor Williams, C. D. Menzies, Craig L. Moyer, Walter Menapace, School of Ocean and Earth Science and Technology (SOEST), University of Hawai‘i [Mānoa] (UHM), University of Alaska [Fairbanks] (UAF), International Ocean Discovery Program, School of Geosciences, University of South Florida, Florida, Tampa, USA, University of South Florida [Tampa] (USF), NAWI Graz Geocentre, Karl-Franzens-Universität [Graz, Autriche], Utah State University (USU), University of Bremen, United States Geological Survey (USGS), University of Cambridge [UK] (CAM), School of Earth and Space Sciences [Hefei], University of Science and Technology of China [Hefei] (USTC), Second Institute of Oceanography, State Oceanic Administration (SOA), Department of Environmental Systems Science [ETH Zürich] (D-USYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), CSIRO Division of Petroleum Resources, Kensington, Australia, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Department of Earth Sciences [Chiba], Chiba University, The University of Tennessee [Knoxville], Instituto Português de Investigação do Mar e da Atmosfera (IPMA), Oceanographic Institute, Univesidade de Sao Paulo, Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, National Oceanography Centre [Southampton] (NOC), University of Southampton, Graduate School of Environmental Studies [Nagoya], Nagoya University, Western Washington University (WWU), Scripps Institution of Oceanography (SIO), University of California [San Diego] (UC San Diego), University of California-University of California, School of Earth and Environmental Sciences [Seoul] (SEES), Seoul National University [Seoul] (SNU), State University of New York (SUNY), IFP Energies nouvelles (IFPEN), Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), GeoRessources, Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS), State Key Laboratory of Marine Environmental Science (Xiamen University), The Natural History Museum [London] (NHM), National Academy of Sciences Washington, Harbor Branch Oceanographic Institute [Fort Pierce], and Florida Atlantic University [Boca Raton]
Subjects: geology, Mariana trench, Serpentinite mud volcanism, Subducted cretaceous seamounts, Exhumed microbes, Evolution of life, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], General Mathematics, Seamount, Origin of Life, Geochemistry, astrobiology, General Physics and Astronomy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Volcanism, Volcanic Eruptions, 010502 geochemistry & geophysics, 01 natural sciences, volcanology, Abiogenesis, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, evolution of life, Convergent boundary, Seawater, 14. Life underwater, 0105 earth and related environmental sciences, geochemistry, geography, Minerals, geography.geographical_feature_category, Subduction, exhumed microbes, General Engineering, Articles, serpentinite mud volcanism, subducted cretaceous seamounts, 13. Climate action, plate tectonics, Mariana Trench, Ridge (meteorology), Geology, Research Article
Abstract: The subduction of seamounts and ridge features at convergent plate boundaries plays an important role in the deformation of the overriding plate and influences geochemical cycling and associated biological processes. Active serpentinization of forearc mantle and serpentinite mud volcanism on the Mariana forearc (between the trench and active volcanic arc) provides windows on subduction processes. Here, we present (1) the first observation of an extensive exposure of an undeformed Cretaceous seamount currently being subducted at the Mariana Trench inner slope; (2) vertical deformation of the forearc region related to subduction of Pacific Plate seamounts and thickened crust; (3) recovered Ocean Drilling Program and International Ocean Discovery Program cores of serpentinite mudflows that confirm exhumation of various Pacific Plate lithologies, including subducted reef limestone; (4) petrologic, geochemical and paleontological data from the cores that show that Pacific Plate seamount exhumation covers greater spatial and temporal extents; (5) the inference that microbial communities associated with serpentinite mud volcanism may also be exhumed from the subducted plate seafloor and/or seamounts; and (6) the implications for effects of these processes with regard to evolution of life. This article is part of a discussion meeting issue ‘Serpentine in the Earth system’.
Published: 2020
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23. On impact and volcanism across the Cretaceous-Paleogene boundary

Author: Hojung Kim, Gregory E Ravizza, Michael J. Henehan, Sofie Jehle, Jonathan D. Schueth, Kasia K. Śliwińska, Philip F Sexton, Donald E. Penman, Ursula Röhl, Roger E. Summons, Alexander Deutsch, Paul A. Wilson, Peter C. Lippert, Tatsuhiko Yamaguchi, Dick Kroon, Jessica H. Whiteside, Julio Sepúlveda, Sietske J. Batenburg, C. Cournede, Kazuyoshi Moriya, Iris Moebius, Richard D Norris, Laia Alegret, D. C. Loroch, Pincelli M. Hull, Oliver Friedrich, Elizabeth C Sibert, Barbara Donner, Paul R. Bown, André Bornemann, Ellen Thomas, James C Zachos, Thomas Westerhold, Daniel J. Peppe, P. Blum, Timothy J. Bralower, Yale University [New Haven], Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ), Scripps Institution of Oceanography (SIO - UC San Diego), University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC), National Oceanography Centre [Southampton] (NOC), University of Southampton, International Ocean Discovery Program, University of Zaragoza - Universidad de Zaragoza [Zaragoza], Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), University of Minnesota [Morris], University of Minnesota System, OCE 1536611, National Science Foundation, NNX09AM88G, National Aeronautics and Space Administration, USSSP Post-Expedition Activity Award, Office of the Director, PRF#52822-DN18, American Chemical Society Petroleum Research Fund, VO687/14, Deutsche Forschungsgemeinschaft, 16H04070, Japan Society for the Promotion of Science, CGL2017-84693-R, Spanish Ministry of Economy and Competitiveness and FEDER, E33_17R, Government of Aragon and FEDER funds, 11-107497, Danish Council for Independent Research/Natural Sciences, Scripps Institution of Oceanography (SIO), University of California-University of California, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)
Subjects: 010504 meteorology & atmospheric sciences, General Science & Technology, Earth science, Cretaceous–Paleogene boundary, Volcanic Eruptions, 010502 geochemistry & geophysics, Extinction, Biological, 01 natural sciences, Global Warming, Carbon cycle, Carbon Cycle, Theoretical, Bolide, Models, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Mexico, 0105 earth and related environmental sciences, Extinction event, Multidisciplinary, Extinction, Global warming, Models, Theoretical, Carbon Dioxide, Biological, Outgassing, 13. Climate action, [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, Flood basalt, Geology
Abstract: An impact with a dash of volcanism Around the time of the end-Cretaceous mass extinction that wiped out dinosaurs, there was both a bolide impact and a large amount of volcanism. Hull et al. ran several temperature simulations based on different volcanic outgassing scenarios and compared them with temperature records across the extinction event. The best model fits to the data required most outgassing to occur before the impact. When combined with other lines of evidence, these models support an impact-driven extinction. However, volcanic gases may have played a role in shaping the rise of different species after the extinction event. Science , this issue p. 266
Published: 2020
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24. The Pliocene Model Intercomparison Project Phase 2: Large-scale climate features and climate sensitivity

Author: A. M. Haywood, J. C. Tindall, H. J. Dowsett, A. M. Dolan, K. M. Foley, S. J. Hunter, D. J. Hill, W.-L. Chan, A. Abe-Ouchi, C. Stepanek, G. Lohmann, D. Chandan, W. R. Peltier, N. Tan, C. Contoux, G. Ramstein, X. Li, Z. Zhang, C. Guo, K. H. Nisancioglu, Q. Zhang, Q. Li, Y. Kamae, M. A. Chandler, L. E. Sohl, B. L. Otto-Bliesner, R. Feng, E. C. Brady, A. S. von der Heydt, M. L. J. Baatsen, D. J. Lunt, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation du climat (CLIM), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), 17189 University of Toronto, U of T Vetenskapsrådet, VR: 2013-06476, 2017-04232 Engineering and Physical Sciences Research Council, EPSRC: EP/M008.363/1 University of Leeds Natural Sciences and Engineering Research Council of Canada, NSERC: A9627 Government of Ontario Ministerio de Educación, Cultura y Deporte, MECD: 024.002.001 National Science Foundation, NSF: 1418411, 1852977 National Center for Atmospheric Research, NCAR Seventh Framework Programme, FP7 China Scholarship Council, CSC: 201804910023 China Postdoctoral Science Foundation: 2015M581154 Netherlands Earth System Science Centre, NESSC European Research Council, ERC: 278636 Japan Society for the Promotion of Science, KAKEN: 17H06104 Ministry of Education, Culture, Sports, Science and Technology, Monbusho: 17H06323 Canada Foundation for Innovation U.S. Geological Survey, USGS Engineering and Physical Sciences Research Council, EPSRC: EP/M008.363/1, Acknowledgements. We acknowledge the use of NOAA_ERSST_V5 data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA, from their website at https://www.esrl.noaa.gov/psd/ (last access: 12 September 2019). Alan M. Haywood, Julia C. Tindall, Aisling M. Dolan, Stephen J. Hunter and Daniel J. Hill acknowledge the FP7 Ideas programme: European Research Council (grant no. PLIO-ESS, 278636), the Past Earth Network (EPSRC grant no. EP/M008.363/1) and the University of Leeds Advanced Research Computing service. Julia C. Tindall was also supported through the Centre for Environmental Modelling and Computation (CEMAC), University of Leeds. Harry J. Dowsett and Kevin M. Foley acknowledge support from the USGS Climate Research and Development Program. This research used samples and/or data provided by the Ocean Drilling Program (ODP) and International Ocean Discovery Program (IODP). Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Bette L. Otto-Bliesner, Esther C. Brady and Ran Feng acknowledge that material for their participation is based upon work supported by the National Center for Atmospheric Research, which is a major facility sponsored by the National Science Foundation (NSF) (cooperative agreement no. 1852977 and NSF OPP grant no. 1418411). The CESM project is supported primarily by the National Science Foundation. Computing and data storage resources, including the Cheyenne supercomputer (https://doi.org/10.5065/D6RX99HX), were provided by the Computational and Information Systems Laboratory (CISL) at NCAR. NCAR is sponsored by the National Science Foundation. Ning Tan, Camille Contoux and Gilles Ramstein were granted access to the HPC resources of TGCC under the allocations 2016-A0030107732, 2017-R0040110492 and 2018-R0040110492 (gencmip6) and 2019-A0050102212 (gen2212) provided by GENCI. The IPSL-CM6 team of the IPSL Climate Modelling Centre (https://cmc.ipsl.fr, last access: 16 September 2020) is acknowledged for having developed, tested, evaluated and tuned the IPSL climate model, as well as per- formed and published the CMIP6 experiments. Christian Stepanek acknowledges funding from the Helmholtz Climate Initiative REKLIM. Christian Stepanek and Gerrit Lohmann acknowledge funding via the Alfred Wegener Institute’s research programme Marine, Coastal and Polar Systems. Qiong Zhang acknowledge support from the Swedish Research Council (2013-06476 and 2017-04232). Simulations with EC-Earth were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC) at the National Supercomputer Centre (NSC). Wing-Le Chan and Ayako Abe-Ouchi acknowledge funding from JSPS (KAKENHI grant no. 17H06104 and MEXT KAKENHI grant no. 17H06323). Their simulations with MIROC4m were performed on the Earth Simulator at JAMSTEC, Yokohama, Japan. The work by Anna S. von der Heydt and Michiel L. J. Baatsen was carried out under the program of the Netherlands Earth System Science Centre (NESSC), financially supported by the Ministry of Education, Culture and Science (OCW grant no. 024.002.001). Simulations with CCSM4-Utr were performed at the SURFsara Dutch national computing facilities and were sponsored by NWO-EW (Netherlands Organisation for Scientific Research, Exact Sciences) (project no. 17189). W. Richard Peltier and Deepak Chandan were supported by Canadian NSERC Discovery Grant A9627, and they wish to acknowledge the support of SciNet HPC Consortium for providing computing facilities. SciNet is funded by the Canada Foundation for Innovation under the auspices of Compute Canada, the Government of Ontario, the Ontario Research Fund – Research Excellence, and the University of Toronto. Xiangyu Li acknowledges financial support from the China Scholarship Council (201804910023) and the China Postdoctoral Science Foundation (project no. 2015M581154). The NorESM simulations benefitted from resources provided by UNINETT Sigma2 – the National Infrastructure for High Performance Computing and Data Storage in Norway. The authors would also like to thank Tim Herbert and an anonymous reviewer for helpful comments on an earlier version of this paper., Financial support. This research has been supported by the Past Earth Network (EPSRC grant no. EP/M008.363/1)., Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)
Subjects: 010504 meteorology & atmospheric sciences, lcsh:Environmental protection, Stratigraphy, Climate change, Zonal and meridional, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, lcsh:Environmental pollution, Pliocene climate, lcsh:TD169-171.8, Precipitation, lcsh:Environmental sciences, 0105 earth and related environmental sciences, lcsh:GE1-350, Global and Planetary Change, geography, geography.geographical_feature_category, Paleontology, 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, lcsh:TD172-193.5, Polar amplification, Environmental science, Climate sensitivity, Climate model, Ice sheet
Abstract: The Pliocene epoch has great potential to improve our understanding of the long-term climatic and environmental consequences of an atmospheric CO2 concentration near ∼400 parts per million by volume. Here we present the large-scale features of Pliocene climate as simulated by a new ensemble of climate models of varying complexity and spatial resolution based on new reconstructions of boundary conditions (the Pliocene Model Intercomparison Project Phase 2; PlioMIP2). As a global annual average, modelled surface air temperatures increase by between 1.7 and 5.2 ∘C relative to the pre-industrial era with a multi-model mean value of 3.2 ∘C. Annual mean total precipitation rates increase by 7 % (range: 2 %–13 %). On average, surface air temperature (SAT) increases by 4.3 ∘C over land and 2.8 ∘C over the oceans. There is a clear pattern of polar amplification with warming polewards of 60∘ N and 60∘ S exceeding the global mean warming by a factor of 2.3. In the Atlantic and Pacific oceans, meridional temperature gradients are reduced, while tropical zonal gradients remain largely unchanged. There is a statistically significant relationship between a model's climate response associated with a doubling in CO2 (equilibrium climate sensitivity; ECS) and its simulated Pliocene surface temperature response. The mean ensemble Earth system response to a doubling of CO2 (including ice sheet feedbacks) is 67 % greater than ECS; this is larger than the increase of 47 % obtained from the PlioMIP1 ensemble. Proxy-derived estimates of Pliocene sea surface temperatures are used to assess model estimates of ECS and give an ECS range of 2.6–4.8 ∘C. This result is in general accord with the ECS range presented by previous Intergovernmental Panel on Climate Change (IPCC) Assessment Reports.
Published: 2020
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25. Expedition 368X Preliminary Report: South China Sea Rifted Margin

Author: Childress, Laurel, Briais, Anne, Deng, Jia-Ming, Lin, Jian, Nirrengarten, Michael, Qiu, Ning, Satolli, Sara, Sun, Zhen, Liang, Yi, Zhong, Lifeng, Géosciences Environnement Toulouse (GET), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), International Ocean Discovery Program (IODP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)
Subjects: [SDU.STU]Sciences of the Universe [physics]/Earth Sciences
Published: 2019

26. Southern Ocean warming and Wilkes Land ice sheet retreat during the mid-Miocene

Author: Sangiorgi, Francesca, Bijl, Peter K., Passchier, Sandra, Salzmann, Ulrich, Schouten, Stefan, McKay, Robert, Cody, Rosemary D., Pross, Jörg, Van De Flierdt, Tina, Bohaty, Steven M, Levy, Richard, Williams, Trevor, Escutia, Carlota, Brinkhuis, Henk, Marine palynology and palaeoceanography, Organic geochemistry, Marine Palynology, International Ocean Discovery Program, National Science Foundation (US), German Research Foundation, Ministerio de Economía y Competitividad (España), European Commission, Natural Environment Research Council (NERC), Marine palynology and palaeoceanography, Organic geochemistry, and Marine Palynology
Subjects: 010504 meteorology & atmospheric sciences, Chemistry(all), Science, Effects of global warming on oceans, TEX86 PROXY, CIRCULATION, Holocene climatic optimum, F700, General Physics and Astronomy, F800, SIZE ANALYSIS, Present day, Structural basin, Physics and Astronomy(all), 010502 geochemistry & geophysics, Biochemistry, 01 natural sciences, Article, General Biochemistry, Genetics and Molecular Biology, DINOFLAGELLATE CYSTS, MD Multidisciplinary, 14. Life underwater, Glacial period, lcsh:Science, 0105 earth and related environmental sciences, geography, Science & Technology, ANTARCTIC CIRCUMPOLAR CURRENT, Multidisciplinary, geography.geographical_feature_category, EAST ANTARCTICA, Biochemistry, Genetics and Molecular Biology(all), MEMBRANE-LIPIDS, ISOPRENOID TETRAETHER LIPIDS, Oceanic climate, EARLY EOCENE, General Chemistry, Multidisciplinary Sciences, Sea surface temperature, Oceanography, 13. Climate action, Science & Technology - Other Topics, lcsh:Q, Ice sheet, CARBON-CYCLE, Geology, Genetics and Molecular Biology(all)
Abstract: Observations and model experiments highlight the importance of ocean heat in forcing ice sheet retreat during the present and geological past, but past ocean temperature data are virtually missing in ice sheet proximal locations. Here we document paleoceanographic conditions and the (in)stability of the Wilkes Land subglacial basin (East Antarctica) during the mid-Miocene (~17-13.4 million years ago) by studying sediment cores from offshore Adélie Coast. Inland retreat of the ice sheet, temperate vegetation, and warm oligotrophic waters characterise the mid-Miocene Climatic Optimum (MCO; 17-14.8 Ma). After the MCO, expansion of a marine-based ice sheet occurs, but remains sensitive to melting upon episodic warm water incursions. Our results suggest that the mid-Miocene latitudinal temperature gradient across the Southern Ocean never resembled that of the present day. We demonstrate that a strong coupling of oceanic climate and Antarctic continental conditions existed and that the East Antarctic subglacial basins were highly sensitive to ocean warming., This research used samples and data from the Integrated Ocean Drilling Program (now International Ocean Discovery Program; IODP). F.S. and H.B. thank NWO (Netherlands Organisation for Scientiﬁc Research) for funding research grant NNPP 866.10.110. P.K.B. was supported through NWO-VENI project number 863.13.002. F.S. thanks the ANDRILL SMS co-chiefs Fabio Florindo and David Harwood. S.P. was supported through the U.S. Science Support Program and the National Science Foundation (OCE 1060080). U.S. acknowledges funding received from the Natural Environment Research Council (NERC Grant NE/H000984/1). R.M. acknowledges support through the Rutherford Discovery Fellowship (RDF-13- VUW-003). The work of S.S. was carried out under the program of the Netherlands Earth System Science Centre (NESSC), which is supported ﬁnancially by the Ministry of Education, Culture and Science (OCW). J.P. acknowledges support through the IODP priority program of the German Research Foundation (DFG). C.E. thanks the Spanish MINECO for scientiﬁc research grant CTM2014-60451-C2-1-P co-funded by the European Union through FEDER funds. Joe Prebble is thanked for providing dinoﬂagellate cyst counts from surface sediment samples of the Southern Ocean.
Published: 2018

27. The dinoflagellate cyst genera Achomosphaera Evitt 1963 and Spiniferites Mantell 1850 in Pliocene to modern sediments: a summary of round table discussions

Author: Marianne Ellegaard, Kenneth Neil Mertens, Serdar Uzar, Nicolas Van Nieuwenhove, Sofia Ribeiro, Kara Bogus, Manuel Bringué, Vera Pospelova, Stijn De Schepper, Barrie Dale, Sophie Warny, Michael Schreck, Stephen Louwye, Laurent Londeix, Maija Heikkilä, André Rochon, Andrea M. Price, Haifeng Gu, Anne de Vernal, Francesca Sangiorgi, Hilal Aydin, Martin J. Head, Vladimir Torres, Arjen Grothe, Karin A F Zonneveld, Kazumi Matsuoka, Gerard J M Versteegh, Peta J. Mudie, Edwige Masure, Aurélie Penaud, Fabienne Marret, Audrey Limoges, Pieter Gurdebeke, Station de Biologie Marine de Concarneau, Direction générale déléguée à la Recherche, à l’Expertise, à la Valorisation et à l’Enseignement-Formation (DGD.REVE), Muséum national d'Histoire naturelle (MNHN)-Muséum national d'Histoire naturelle (MNHN), Centre de recherche sur la dynamique du système Terre (GEOTOP), Université de Montréal (UdeM)-McGill University = Université McGill [Montréal, Canada]-École Polytechnique de Montréal (EPM)-Concordia University [Montreal]-Université du Québec à Rimouski (UQAR)-Université du Québec à Montréal = University of Québec in Montréal (UQAM)-Université du Québec en Abitibi-Témiscamingue (UQAT), Department of Plant and Environmental Sciences [Copenhagen], Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Marine Palynology and Palaeoceanography, Utrecht University [Utrecht], Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Department of Geography, University of Liverpool, Paléobiodiversité et paléoenvironnements, Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire Géosciences Océan (LGO), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la MER de Rimouski (ISMER), Université du Québec à Rimouski (UQAR), Faculty of Geosciences [Utrecht], Louisiana State University (LSU), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Marine palynology and palaeoceanography, Marine Palynology, Ifremer, LER BO, Station de Biologie Marine, Place de la Croix, Concarneau CEDEX, France, Department of Geoscience, Aarhus University, Aarhus, Denmark, Department of Geology, Ghent University, Ghent, Belgium, Biology Department, Faculty of Sciences and Arts, Celal Bayar University, Manisa, Turkey, International Ocean Discovery Program, Texas A&M University, College Station, TX, United States, School of the Earth, Ocean and Environment, University of South Carolina, Columbia, SC, United States, School of Earth and Ocean Sciences, University of Victoria, Victoria, BC, Canada, Geosciences Department, University of Oslo, Oslo, Norway, Uni Research Climate, Bjerknes Centre for Climate Research, Bergen, Norway, Département des sciences de la Terre et de l’Atmosphère, Geotop, Université du Québec à Montréal, Montreal, Canada, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark, Marine Palynology and Paleoceanography, Laboratory of Palaeobotany and Palynology, Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, Netherlands, Third Institute of Oceanography, SOA, Xiamen, China, Department of Earth Sciences, Brock University, St. Catharines, ON, Canada, Environmental Change Research Unit, Department of Environmental Sciences, University of Helsinki, Finland, Department of Glaciology and Climate, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark, Université de Bordeaux, UMR 5805 EPOC, Pessac CEDEX, France, School of Environmental Sciences, University of Liverpool, Liverpool, United Kingdom, CR2P Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements, UMR7207–CNRS, MNHN, UPMC, Paris, France, Institute for East China Sea Research (ECSER), Nagasaki, Japan, Geological Survey of Canada, Dartmouth, Canada, UMR6538 Domaines Océaniques, IUEM-UBO, Plouzané, France, Department of Geography, McGill University, Montréal, Canada, ISMER-UQAR, 310 allée des Ursulines, Rimouski, QC, Canada, Department of Geology, University of Tromsø–The Arctic University, Tromsø, Langnes, Norway, Biostratigraphy Core Group, ExxonMobil Exploration Company, Spring, TX, United States, Department of Marine Geochemistry, Alfred-Wegener-Institut (AWI), Helmholtz Zentrum für Polar und Meeresforschung, Bremerhaven, Germany, MARUM–Center for Marine Environmental Sciences, Bremen University, Bremen, Germany, Department of Geology and Geophysics and Museum of Natural Science, Louisiana State University, Baton Rouge, LA, United States, and Department of Earth Sciences, University of New Brunswick, Fredericton, Canada
Subjects: DINOFLAGELLATE, 010506 paleontology, 010502 geochemistry & geophysics, 01 natural sciences, Pterocysta, Genus, Rottnestia, VDP::Matematikk og Naturvitenskap: 400::Geofag: 450, Hafniasphaera, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, NORTHERN BELGIUM, 14. Life underwater, ASSEMBLAGES, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 0105 earth and related environmental sciences, [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, VDP::Mathematics and natural science: 400::Geosciences: 450, LATE QUATERNARY, biology, Achomosphaera, Spiniferites, Dinoflagellate, Biology and Life Sciences, Paleontology, DINOPHYCEAE, biology.organism_classification, Archaeology, CENOZOIC, EEMIAN HYDROGRAPHIC CONDITIONS, Geography, Baltic sea, Round table, Earth and Environmental Sciences, BALTIC SEA, SP-NOV, MORPHOLOGY, [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology, Cenozoic, PROPOSALS, Dinophyceae
Abstract: We present a summary of two round-table discussions held during two subsequent workshops in Montreal (Canada) on 16 April 2014 and Ostend (Belgium) on 8 July 2015. Five species of the genus Achomosphaera Evitt 1963 Evitt WR. 1963. A discussion and proposals concerning fossil dinoflagellates, hystrichospheres, and acritarchs, I. National Academy of Sciences, Washington, Proceedings. 49(2):158–164.[Crossref], [PubMed], [Web of Science ®], , [Google Scholar] and 33 of the genus Spiniferites Mantell 1850 emend. Sarjeant 1970 Sarjeant WAS. 1970. The genus Spiniferites Mantell, 1850 (Dinophyceae). Grana. 10(1):74–78.[Taylor & Francis Online], , [Google Scholar] occuring in Pliocene to modern sediments are listed and briefly described along with remarks made by workshop participants. In addition, several holotypes and topotypes are reillustrated. Three species previously assigned to Spiniferites are here considered/accepted as belonging to other genera: Impagidinium inaequalis (Wall and Dale in Wall et al. 1973 Wall D, Dale B, Harada K. 1973. Descriptions of new fossil dinoflagellates from the Late Quaternary of the Black Sea. Micropaleontology. 19(1):18–31.[Crossref], , [Google Scholar]) Londeix et al. 2009 Londeix L, Herreyre Y, Turon J-L, Fletcher W. 2009. Last Glacial to Holocene hydrology of the Marmara Sea inferred from a dinoflagellate cyst record. Rev Palaeobot Palynol. 158(1-2):52–71.[Crossref], [Web of Science ®], , [Google Scholar], Spiniferites? rubinus (Rossignol 1962 Rossignol M. 1962. Analyse pollinique de sédiments marins quaternaires en Israël II. - Sédiments pleistocènes. Pollen et Spores. 4:121–148. [Google Scholar] ex Rossignol 1964 Rossignol M. 1964. Hystrichosphères du Quaternaire en Méditerranée orientale, dans les sédiments Pléistocènes et les boues marines actuelles. Revue de Micropaléontologie. 7:83–99. [Google Scholar]) Sarjeant 1970 Sarjeant WAS. 1970. The genus Spiniferites Mantell, 1850 (Dinophyceae). Grana. 10(1):74–78.[Taylor & Francis Online], , [Google Scholar], and Thalassiphora balcanica Balteş 1971. This summary forms the basis for a set of papers that follows, where points raised during the workshops are explored in greater detail.
Published: 2018
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28. Expedition 369 Preliminary Report: Australia Cretaceous Climate and Tectonics

Author: Huber, B.T., Hobbs, R.W., Bogus, K.A., Participants, Expedition 369 Scientific, Martinez, Mathieu, Géosciences Rennes (GR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), International Ocean Discovery Program, Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), and Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology
Published: 2018

29. Quantifying the Release of Climate‐Active Gases by Large Meteorite Impacts With a Case Study of Chicxulub

Author: Artemieva , Natalia, Morgan , Joanna, Gulick , S.P.S., Chenot , E., Christeson , G.L., Claeys , P., Cockell , C.S., Coolen , M.J.L., Ferrière , L., Gebhardt , C., Goto , K., Green , S., Jones , H., Kring , D.A., Lofi , J., Lowery , C.M., Ocampo-Torres , R., Perez-Cruz , L., Pickersgill , A.E., Poelchau , M., Rae , A.S.P., Rasmussen , C., Rebolledo-Vieyra , M., Riller , U., Sato , H., Smit , J., Tikoo , S.M., Tomioka , N., Urrutia-Fucugauchi , J., Whalen , M.T., Wittmann , A., Xiao , L., Yamaguchi , K.E., Zylberman , W., Collins , G.S., Bralower , T.J., Biogéosciences [Dijon] ( BGS ), Université de Bourgogne ( UB ) -AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique ( CNRS ), Géosciences Montpellier, Université des Antilles et de la Guyane ( UAG ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Université de Montpellier ( UM ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de chimie et procédés pour l'énergie, l'environnement et la santé ( ICPEES ), Université de Strasbourg ( UNISTRA ) -Centre National de la Recherche Scientifique ( CNRS ) -Matériaux et nanosciences d'Alsace, Université de Strasbourg ( UNISTRA ) -Université de Haute-Alsace (UHA) Mulhouse - Colmar ( Université de Haute-Alsace (UHA) ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Strasbourg ( UNISTRA ) -Université de Haute-Alsace (UHA) Mulhouse - Colmar ( Université de Haute-Alsace (UHA) ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), Centre européen de recherche et d'enseignement de géosciences de l'environnement ( CEREGE ), Centre National de la Recherche Scientifique ( CNRS ) -Institut de Recherche pour le Développement ( IRD ) -Aix Marseille Université ( AMU ) -Collège de France ( CdF ) -Institut National de la Recherche Agronomique ( INRA ) -Institut national des sciences de l'Univers ( INSU - CNRS ), Funding from the International Ocean Discovery Program (IODP), the International Continental scientific Drilling Project (ICDP), NASA grant 15-EXO15_2-0054 and NERC grant NE/P005217/1., Natural Environment Research Council (NERC), The Leverhulme Trust, Biogéosciences [UMR 6282] [Dijon] (BGS), Centre National de la Recherche Scientifique (CNRS)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Biogéosciences [UMR 6282] (BGS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Earth science, Potentially hazardous object, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Sediment, [ SDU.STU ] Sciences of the Universe [physics]/Earth Sciences, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, Shock (mechanics), Water depth, Geophysics, Meteorite, Volume (thermodynamics), 13. Climate action, Meteorology & Atmospheric Sciences, General Earth and Planetary Sciences, Sedimentary rock, Porosity, Geology, 0105 earth and related environmental sciences
Abstract: 9 pages; International audience; Potentially hazardous asteroids and comets have hit Earth throughout its history, with catastrophic consequences in the case of the Chicxulub impact. Here we reexamine one of the mechanisms that allow an impact to have a global effect—the release of climate-active gases from sedimentary rocks. We use the SOVA hydrocode and model ejected materials for a sufficient time after impact to quantify the volume of gases that reach high enough altitudes (> 25 km) to have global consequences. We vary impact angle, sediment thickness and porosity, water depth, and shock pressure for devolatilization and present the results in a dimensionless form so that the released gases can be estimated for any impact into a sedimentary target. Using new constraints on the Chicxulub impact angle and target composition, we estimate that 325 ± 130 Gt of sulfur and 425 ± 160 Gt CO2 were ejected and produced severe changes to the global climate.
Published: 2017
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30. Site U1455

Author: France-Lanord, Christian, Spiess, Volkhard, Klaus, Adam, Adhikari, R.R., Adhikari, S.K., Bahk, J.-J., Baxter, A.T., Cruz, J.W., Das, S.K., Dekens, P., Duleba, W., Fox, L.R., Galy, Albert, Galy, V., Ge, J., Gleason, J.D., Gyawali, B.R., Huyghe, P., Jia, G., Lantzsch, H., Manoj, M.C., Y. Martos, Martin, Meynadier, L., Najman, Y.M.R., Nakajima, A., Ponton, C., Reilly, B.T., Rogers, K.G., Savian, J.F., Schwenk, T., Selkin, P.A., Weber, M.E., Williams, T., Yoshida, K., Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), University of Bremen, Texas A&M University [College Station], Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Shimane University, Korea Institute of Geoscience & Mineral Resources (KIGAM), School of Environmental and Rural Sciences, University of New England (UNE), Florida State University [Tallahassee] (FSU), Presidency University, San Francisco State University (SFSU), Universidade de São Paulo (USP), University of Leeds, Woods Hole Oceanographic Institution (WHOI), Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences [Beijing] (CAS), University of Michigan [Ann Arbor], University of Michigan System, Tohoku University [Sendai], Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Guangzhou Institute of Geochemistry, Birbal Sahni Institute of Palaeobotany, International Ocean Discovery Program, Institut de Physique du Globe de Paris, Lancaster Environment Centre, Lancaster University, Yamaguchi University [Yamaguchi], University of Southern California (USC), Oregon State University (OSU), University of Colorado [Boulder], Universidade Federal do Rio Grande do Sul [Porto Alegre] (UFRGS), University of Washington (Tacoma), Universität zu Köln, Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Shinshu University [Nagano], Universidade de São Paulo = University of São Paulo (USP), Institut de Physique du Globe de Paris (IPG Paris), and Universität zu Köln = University of Cologne
Subjects: International Ocean Discovery Program, Site U1455, 010504 meteorology & atmospheric sciences, [SDU]Sciences of the Universe [physics], Bengal Fan, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Expedition 354, 010502 geochemistry & geophysics, 01 natural sciences, ComputingMilieux_MISCELLANEOUS, IODP, JOIDES Resolution, 0105 earth and related environmental sciences
Abstract: International audience
Published: 2016
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31. A long section of serpentinized depleted mantle peridotite.

Author: Lissenberg CJ, McCaig AM, Lang SQ, Blum P, Abe N, Brazelton WJ, Coltat R, Deans JR, Dickerson KL, Godard M, John BE, Klein F, Kuehn R, Lin KY, Liu H, Lopes EL, Nozaka T, Parsons AJ, Pathak V, Reagan MK, Robare JA, Savov IP, Schwarzenbach EM, Sissmann OJ, Southam G, Wang F, Wheat CG, Anderson L, and Treadwell S
Abstract: The upper mantle is critical for our understanding of terrestrial magmatism, crust formation, and element cycling between Earth's solid interior, hydrosphere, atmosphere, and biosphere. Mantle composition and evolution have been primarily inferred by surface sampling and indirect methods. We recovered a long (1268-meter) section of serpentinized abyssal mantle peridotite interleaved with thin gabbroic intrusions. We find depleted compositions with notable variations in mantle mineralogy controlled by melt flow. Dunite zones have predominantly intermediate dips, in contrast to the originally steep mantle fabrics, indicative of oblique melt transport. Extensive hydrothermal fluid-rock interaction is recorded across the full depth of the core and is overprinted by oxidation in the upper 200 meters. Alteration patterns are consistent with vent fluid composition in the nearby Lost City hydrothermal field.
Published: 2024
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32. Ice sheet-free West Antarctica during peak early Oligocene glaciation.

Author: Klages JP, Hillenbrand CD, Bohaty SM, Salzmann U, Bickert T, Lohmann G, Knahl HS, Gierz P, Niu L, Titschack J, Kuhn G, Frederichs T, Müller J, Bauersachs T, Larter RD, Hochmuth K, Ehrmann W, Nehrke G, Rodríguez-Tovar FJ, Schmiedl G, Spezzaferri S, Läufer A, Lisker F, van de Flierdt T, Eisenhauer A, Uenzelmann-Neben G, Esper O, Smith JA, Pälike H, Spiegel C, Dziadek R, Ronge TA, Freudenthal T, and Gohl K
Abstract: One of Earth's most fundamental climate shifts, the greenhouse-icehouse transition 34 million years ago, initiated Antarctic ice sheet buildup, influencing global climate until today. However, the extent of the ice sheet during the Early Oligocene Glacial Maximum (~33.7 to 33.2 million years ago) that immediately followed this transition-a critical knowledge gap for assessing feedbacks between permanently glaciated areas and early Cenozoic global climate reorganization-is uncertain. In this work, we present shallow-marine drilling data constraining earliest Oligocene environmental conditions on West Antarctica's Pacific margin-a key region for understanding Antarctic ice sheet evolution. These data indicate a cool-temperate environment with mild ocean and air temperatures that prevented West Antarctic Ice Sheet formation. Climate-ice sheet modeling corroborates a highly asymmetric Antarctic ice sheet, thereby revealing its differential regional response to past and future climatic change.
Published: 2024
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33. Five million years of Antarctic Circumpolar Current strength variability.

Author: Lamy F, Winckler G, Arz HW, Farmer JR, Gottschalk J, Lembke-Jene L, Middleton JL, van der Does M, Tiedemann R, Alvarez Zarikian C, Basak C, Brombacher A, Dumm L, Esper OM, Herbert LC, Iwasaki S, Kreps G, Lawson VJ, Lo L, Malinverno E, Martinez-Garcia A, Michel E, Moretti S, Moy CM, Ravelo AC, Riesselman CR, Saavedra-Pellitero M, Sadatzki H, Seo I, Singh RK, Smith RA, Souza AL, Stoner JS, Toyos M, de Oliveira IMVP, Wan S, Wu S, and Zhao X
Abstract: The Antarctic Circumpolar Current (ACC) represents the world's largest ocean-current system and affects global ocean circulation, climate and Antarctic ice-sheet stability 1-3 . Today, ACC dynamics are controlled by atmospheric forcing, oceanic density gradients and eddy activity 4 . Whereas palaeoceanographic reconstructions exhibit regional heterogeneity in ACC position and strength over Pleistocene glacial-interglacial cycles 5-8 , the long-term evolution of the ACC is poorly known. Here we document changes in ACC strength from sediment cores in the Pacific Southern Ocean. We find no linear long-term trend in ACC flow since 5.3 million years ago (Ma), in contrast to global cooling 9 and increasing global ice volume 10 . Instead, we observe a reversal on a million-year timescale, from increasing ACC strength during Pliocene global cooling to a subsequent decrease with further Early Pleistocene cooling. This shift in the ACC regime coincided with a Southern Ocean reconfiguration that altered the sensitivity of the ACC to atmospheric and oceanic forcings 11-13 . We find ACC strength changes to be closely linked to 400,000-year eccentricity cycles, probably originating from modulation of precessional changes in the South Pacific jet stream linked to tropical Pacific temperature variability 14 . A persistent link between weaker ACC flow, equatorward-shifted opal deposition and reduced atmospheric CO 2 during glacial periods first emerged during the Mid-Pleistocene Transition (MPT). The strongest ACC flow occurred during warmer-than-present intervals of the Plio-Pleistocene, providing evidence of potentially increasing ACC flow with future climate warming., (© 2024. The Author(s).)
Published: 2024
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34. Sedimentary DNA reveals the link between microbial community dynamics and climate during the late last glaciation in the offshore region of the Zambezi River, Southwest Indian Ocean.

Author: Li H, Zhang H, Li H, Duan L, Zhang X, Gao Y, Hall IR, Hemming SR, and LeVay LJ
Subjects: Indian Ocean, Biodiversity, DNA, Rivers, Microbiota
Abstract: Reconstructing the relationship between microbial communities and past abrupt climate change is of great importance for understanding current biodiversity patterns and predicting changes under future climate scenarios. However, little is currently known about how microbial communities respond to changes in key environmental stages due to a lack of research in this area. Here, we examine the variability in the communities of bacteria, archaea, and fungi from sediments deposited offshore region of the Zambezi River between 21.7 and 9.6 thousand years ago (ka) (covering the last glacial maximum, or LGM, and the early Holocene) using DNA metabarcoding approach via high-throughput sequencing. The results showed that (1) microbial assemblages differed across three key time intervals, with the last deglaciation having the most homogeneous prokaryotic assemblages, while for fungal communities in the LGM, and the early Holocene and LGM differing the most; (2) the warm early Holocene showed the highest diversity, whereas the lowest diversity was found in the LGM; and (3) the selected indicator species better reflected the climatic characteristics of different environmental stages. These results highlight the power of ancient sedimentary DNA to refine our understanding of microbial dynamics in marine sedimentary systems near large rivers, thus providing a basis for better modeling ecological processes in further research., Competing Interests: Declaration of competing interest None declared., (Copyright © 2023 Elsevier B.V. All rights reserved.)
Published: 2024
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35. Anomalous widespread arid events in Asia over the past 550,000 years.

Author: Carrasqueira IGDF, Jovane L, Droxler AW, Alvarez Zarikian CA, Lanci L, Alonso-Garcia M, Laya JC, and Kroon D
Abstract: Records of element ratios obtained from the Maldives Inner Sea sediments provide a detailed view on how the Indian Monsoon System has varied at high-resolution time scales. Here, we present records from International Ocean Discovery Program (IODP) Site U1471 based on a refined chronology through the past 550,000 years. The record's high resolution and a proper approach to set the chronology allowed us to reconstruct changes in the Indian Monsoon System on a scale of anomalies and to verify their relationships with established records from the East Asian Monsoon System. On the basis of Fe/sum and Fe/Si records, it can be demonstrated that the Asia continental aridity tracks sea-level changes, while the intensity of winter monsoon winds responds to changes in Northern Hemisphere summer insolation. Furthermore, the anomalies of continental aridity and intensity of winter monsoon winds at millennial-scale events exhibit power in the precession band, nearly in antiphase with Northern Hemisphere summer insolation. These observations indicate that the insolation drove the anomalies in the Indian Summer Monsoon. The good correspondence between our record and the East Asian monsoon anomaly records suggests the occurrence of anomalous widespread arid events in Asia., (© The Author(s) 2023. Published by Oxford University Press on behalf of National Academy of Sciences.)
Published: 2023
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36. Insights into the deglacial variability of phytoplankton community structure in the eastern equatorial Pacific Ocean using [ 231 Pa/ 230 Th]xs and opal-carbonate fluxes.

Author: Schimmenti D, Marcantonio F, Hayes CT, Hertzberg J, Schmidt M, and Sarao J
Subjects: Pacific Ocean, Carbon, Carbonates, Phytoplankton, Seawater chemistry
Abstract: Fully and accurately reconstructing changes in oceanic productivity and carbon export and their controls is critical to determining the efficiency of the biological pump and its role in the global carbon cycle through time, particularly in modern CO 2 source regions like the eastern equatorial Pacific (EEP). Here we present new high-resolution records of sedimentary 230 Th-normalized opal and nannofossil carbonate fluxes and [ 231 Pa/ 230 Th]xs ratios from site MV1014-02-17JC in the Panama Basin. We find that, across the last deglaciation, phytoplankton community structure is driven by changing patterns of nutrient (nitrate, iron, and silica) availability which, in turn, are caused by variability in the position of the Intertropical Convergence Zone (ITCZ) and associated changes in biogeochemical cycling and circulation in the Southern Ocean. Our multi-proxy work suggests greater scrutiny is required in the interpretation of common geochemical proxies of productivity and carbon export in the EEP., (© 2022. The Author(s).)
Published: 2022
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37. Ancient marine sediment DNA reveals diatom transition in Antarctica.

Author: Armbrecht L, Weber ME, Raymo ME, Peck VL, Williams T, Warnock J, Kato Y, Hernández-Almeida I, Hoem F, Reilly B, Hemming S, Bailey I, Martos YM, Gutjahr M, Percuoco V, Allen C, Brachfeld S, Cardillo FG, Du Z, Fauth G, Fogwill C, Garcia M, Glüder A, Guitard M, Hwang JH, Iizuka M, Kenlee B, O'Connell S, Pérez LF, Ronge TA, Seki O, Tauxe L, Tripathi S, and Zheng X
Subjects: Antarctic Regions, DNA, Ancient, Ecosystem, Eukaryota, Geologic Sediments, Diatoms genetics
Abstract: Antarctica is one of the most vulnerable regions to climate change on Earth and studying the past and present responses of this polar marine ecosystem to environmental change is a matter of urgency. Sedimentary ancient DNA (sedaDNA) analysis can provide such insights into past ecosystem-wide changes. Here we present authenticated (through extensive contamination control and sedaDNA damage analysis) metagenomic marine eukaryote sedaDNA from the Scotia Sea region acquired during IODP Expedition 382. We also provide a marine eukaryote sedaDNA record of ~1 Mio. years and diatom and chlorophyte sedaDNA dating back to ~540 ka (using taxonomic marker genes SSU, LSU, psbO). We find evidence of warm phases being associated with high relative diatom abundance, and a marked transition from diatoms comprising <10% of all eukaryotes prior to ~14.5 ka, to ~50% after this time, i.e., following Meltwater Pulse 1A, alongside a composition change from sea-ice to open-ocean species. Our study demonstrates that sedaDNA tools can be expanded to hundreds of thousands of years, opening the pathway to the study of ecosystem-wide marine shifts and paleo-productivity phases throughout multiple glacial-interglacial cycles., (© 2022. The Author(s).)
Published: 2022
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38. Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments.

Author: Bailey I, Hemming S, Reilly BT, Rollinson G, Williams T, Weber ME, Raymo ME, Peck VL, Ronge TA, Brachfeld S, O'Connell S, Tauxe L, Warnock JP, Armbrecht L, Cardillo FG, Du Z, Fauth G, Garcia M, Glueder A, Guitard M, Gutjahr M, Hernández-Almeida I, Hoem FS, Hwang JH, Iizuka M, Kato Y, Kenlee B, Martos YM, Pérez LF, Seki O, Tripathi S, and Zheng X
Abstract: Ice loss in the Southern Hemisphere has been greatest over the past 30 years in West Antarctica. The high sensitivity of this region to climate change has motivated geologists to examine marine sedimentary records for evidence of past episodes of West Antarctic Ice Sheet (WAIS) instability. Sediments accumulating in the Scotia Sea are useful to examine for this purpose because they receive iceberg-rafted debris (IBRD) sourced from the Pacific- and Atlantic-facing sectors of West Antarctica. Here we report on the sedimentology and provenance of the oldest of three cm-scale coarse-grained layers recovered from this sea at International Ocean Discovery Program Site U1538. These layers are preserved in opal-rich sediments deposited ∼1.2 Ma during a relatively warm regional climate. Our microCT-based analysis of the layer's in-situ fabric confirms its ice-rafted origin. We further infer that it is the product of an intense but short-lived episode of IBRD deposition. Based on the petrography of its sand fraction and the Phanerozoic 40 Ar/ 39 Ar ages of hornblende and mica it contains, we conclude that the IBRD it contains was likely sourced from the Weddell Sea and/or Amundsen Sea embayment(s) of West Antarctica. We attribute the high concentrations of IBRD in these layers to "dirty" icebergs calved from the WAIS following its retreat inland from its modern grounding line. These layers also sit at the top of a ∼366-m thick Pliocene and early Pleistocene sequence that is much more dropstone-rich than its overlying sediments. We speculate this fact may reflect that WAIS mass-balance was highly dynamic during the ∼41-kyr (inter)glacial world., (© 2022. The Authors.)
Published: 2022
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39. Persistent influence of precession on northern ice sheet variability since the early Pleistocene.

Author: Barker S, Starr A, van der Lubbe J, Doughty A, Knorr G, Conn S, Lordsmith S, Owen L, Nederbragt A, Hemming S, Hall I, Levay L, Berke MA, Brentegani L, Caley T, Cartagena-Sierra A, Charles CD, Coenen JJ, Crespin JG, Franzese AM, Gruetzner J, Han X, Hines SKV, Jimenez Espejo FJ, Just J, Koutsodendris A, Kubota K, Lathika N, Norris RD, Periera Dos Santos T, Robinson R, Rolison JM, Simon MH, Tangunan D, Yamane M, and Zhang H
Abstract: Prior to ~1 million years ago (Ma), variations in global ice volume were dominated by changes in obliquity; however, the role of precession remains unresolved. Using a record of North Atlantic ice rafting spanning the past 1.7 million years, we find that the onset of ice rafting within a given glacial cycle (reflecting ice sheet expansion) consistently occurred during times of decreasing obliquity whereas mass ice wasting (ablation) events were consistently tied to minima in precession. Furthermore, our results suggest that the ubiquitous association between precession-driven mass wasting events and glacial termination is a distinct feature of the mid to late Pleistocene. Before then (increasing), obliquity alone was sufficient to end a glacial cycle, before losing its dominant grip on deglaciation with the southward extension of Northern Hemisphere ice sheets since ~1 Ma.
Published: 2022
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40. Antiphased dust deposition and productivity in the Antarctic Zone over 1.5 million years.

Author: Weber ME, Bailey I, Hemming SR, Martos YM, Reilly BT, Ronge TA, Brachfeld S, Williams T, Raymo M, Belt ST, Smik L, Vogel H, Peck VL, Armbrecht L, Cage A, Cardillo FG, Du Z, Fauth G, Fogwill CJ, Garcia M, Garnsworthy M, Glüder A, Guitard M, Gutjahr M, Hernández-Almeida I, Hoem FS, Hwang JH, Iizuka M, Kato Y, Kenlee B, OConnell S, Pérez LF, Seki O, Stevens L, Tauxe L, Tripathi S, Warnock J, and Zheng X
Subjects: Antarctic Regions, Atmosphere, Oceans and Seas, Dust analysis, Seawater
Abstract: The Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in influencing the carbon cycle. We report a high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia. Our deep-ocean records cover the last 1.5 Ma, thus doubling that from Antarctic ice-cores. We find a 5 to 15-fold increase in dust deposition during glacials and a 2 to 5-fold increase in biogenic silica deposition, reflecting higher ocean productivity during interglacials. This antiphasing persisted throughout the last 25 glacial cycles. Dust deposition became more pronounced across the Mid-Pleistocene Transition (MPT) in the Southern Hemisphere, with an abrupt shift suggesting more severe glaciations since ~0.9 Ma. Productivity was intermediate pre-MPT, lowest during the MPT and highest since 0.4 Ma. Generally, glacials experienced extended sea-ice cover, reduced bottom-water export and Weddell Gyre dynamics, which helped lower atmospheric CO 2 levels., (© 2022. The Author(s).)
Published: 2022
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41. A large West Antarctic Ice Sheet explains early Neogene sea-level amplitude.

Author: Marschalek JW, Zurli L, Talarico F, van de Flierdt T, Vermeesch P, Carter A, Beny F, Bout-Roumazeilles V, Sangiorgi F, Hemming SR, Pérez LF, Colleoni F, Prebble JG, van Peer TE, Perotti M, Shevenell AE, Browne I, Kulhanek DK, Levy R, Harwood D, Sullivan NB, Meyers SR, Griffith EM, Hillenbrand CD, Gasson E, Siegert MJ, Keisling B, Licht KJ, Kuhn G, Dodd JP, Boshuis C, De Santis L, and McKay RM
Subjects: Antarctic Regions, Climate Models, History, Ancient, Ice Cover, Sea Level Rise history, Seawater analysis
Abstract: Early to Middle Miocene sea-level oscillations of approximately 40-60 m estimated from far-field records 1-3 are interpreted to reflect the loss of virtually all East Antarctic ice during peak warmth 2 . This contrasts with ice-sheet model experiments suggesting most terrestrial ice in East Antarctica was retained even during the warmest intervals of the Middle Miocene 4,5 . Data and model outputs can be reconciled if a large West Antarctic Ice Sheet (WAIS) existed and expanded across most of the outer continental shelf during the Early Miocene, accounting for maximum ice-sheet volumes. Here we provide the earliest geological evidence proving large WAIS expansions occurred during the Early Miocene (~17.72-17.40 Ma). Geochemical and petrographic data show glacimarine sediments recovered at International Ocean Discovery Program (IODP) Site U1521 in the central Ross Sea derive from West Antarctica, requiring the presence of a WAIS covering most of the Ross Sea continental shelf. Seismic, lithological and palynological data reveal the intermittent proximity of grounded ice to Site U1521. The erosion rate calculated from this sediment package greatly exceeds the long-term mean, implying rapid erosion of West Antarctica. This interval therefore captures a key step in the genesis of a marine-based WAIS and a tipping point in Antarctic ice-sheet evolution., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)
Published: 2021
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42. Southern Ocean contribution to both steps in deglacial atmospheric CO 2 rise.

Author: Ronge TA, Frische M, Fietzke J, Stephens AL, Bostock H, and Tiedemann R
Abstract: The transfer of vast amounts of carbon from a deep oceanic reservoir to the atmosphere is considered to be a dominant driver of the deglacial rise in atmospheric CO 2 . Paleoceanographic reconstructions reveal evidence for the existence of CO 2 -rich waters in the mid to deep Southern Ocean. These water masses ventilate to the atmosphere south of the Polar Front, releasing CO 2 prior to the formation and subduction of intermediate-waters. Changes in the amount of CO 2 in the sea water directly affect the oceanic carbon chemistry system. Here we present B/Ca ratios, a proxy for delta carbonate ion concentrations Δ[CO 3 2- ], and stable isotopes (δ 13 C) from benthic foraminifera from a sediment core bathed in Antarctic Intermediate Water (AAIW), offshore New Zealand in the Southwest Pacific. We find two transient intervals of rising [CO 3 2- via the Southern Ocean. These intervals coincide with the two pulses in rising atmospheric CO 13 C that that are consistent with the release of CO 2 from the deep ocean to surface and atmospheric reservoirs during the last deglaciation, although further work is required to pin down the detailed carbon transfer pathways.2 at ~ 17.5-14.3 ka and 12.9-11.1 ka. Our results lend support for the release of sequestered CO 2 from the deep ocean to surface and atmospheric reservoirs during the last deglaciation, although further work is required to pin down the detailed carbon transfer pathways., (© 2021. The Author(s).)
Published: 2021
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43. Antarctic icebergs reorganize ocean circulation during Pleistocene glacials.

Author: Starr A, Hall IR, Barker S, Rackow T, Zhang X, Hemming SR, van der Lubbe HJL, Knorr G, Berke MA, Bigg GR, Cartagena-Sierra A, Jiménez-Espejo FJ, Gong X, Gruetzner J, Lathika N, LeVay LJ, Robinson RS, and Ziegler M
Abstract: The dominant feature of large-scale mass transfer in the modern ocean is the Atlantic meridional overturning circulation (AMOC). The geometry and vigour of this circulation influences global climate on various timescales. Palaeoceanographic evidence suggests that during glacial periods of the past 1.5 million years the AMOC had markedly different features from today 1 ; in the Atlantic basin, deep waters of Southern Ocean origin increased in volume while above them the core of the North Atlantic Deep Water (NADW) shoaled 2 . An absence of evidence on the origin of this phenomenon means that the sequence of events leading to global glacial conditions remains unclear. Here we present multi-proxy evidence showing that northward shifts in Antarctic iceberg melt in the Indian-Atlantic Southern Ocean (0-50° E) systematically preceded deep-water mass reorganizations by one to two thousand years during Pleistocene-era glaciations. With the aid of iceberg-trajectory model experiments, we demonstrate that such a shift in iceberg trajectories during glacial periods can result in a considerable redistribution of freshwater in the Southern Ocean. We suggest that this, in concert with increased sea-ice cover, enabled positive buoyancy anomalies to 'escape' into the upper limb of the AMOC, providing a teleconnection between surface Southern Ocean conditions and the formation of NADW. The magnitude and pacing of this mechanism evolved substantially across the mid-Pleistocene transition, and the coeval increase in magnitude of the 'southern escape' and deep circulation perturbations implicate this mechanism as a key feedback in the transition to the '100-kyr world', in which glacial-interglacial cycles occur at roughly 100,000-year periods.
Published: 2021
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44. Slow slip source characterized by lithological and geometric heterogeneity.

Author: Barnes PM, Wallace LM, Saffer DM, Bell RE, Underwood MB, Fagereng A, Meneghini F, Savage HM, Rabinowitz HS, Morgan JK, Kitajima H, Kutterolf S, Hashimoto Y, Engelmann de Oliveira CH, Noda A, Crundwell MP, Shepherd CL, Woodhouse AD, Harris RN, Wang M, Henrys S, Barker DHN, Petronotis KE, Bourlange SM, Clennell MB, Cook AE, Dugan BE, Elger J, Fulton PM, Gamboa D, Greve A, Han S, Hüpers A, Ikari MJ, Ito Y, Kim GY, Koge H, Lee H, Li X, Luo M, Malie PR, Moore GF, Mountjoy JJ, McNamara DD, Paganoni M, Screaton EJ, Shankar U, Shreedharan S, Solomon EA, Wang X, Wu HY, Pecher IA, and LeVay LJ
Abstract: Slow slip events (SSEs) accommodate a significant proportion of tectonic plate motion at subduction zones, yet little is known about the faults that actually host them. The shallow depth (<2 km) of well-documented SSEs at the Hikurangi subduction zone offshore New Zealand offers a unique opportunity to link geophysical imaging of the subduction zone with direct access to incoming material that represents the megathrust fault rocks hosting slow slip. Two recent International Ocean Discovery Program Expeditions sampled this incoming material before it is entrained immediately down-dip along the shallow plate interface. Drilling results, tied to regional seismic reflection images, reveal heterogeneous lithologies with highly variable physical properties entering the SSE source region. These observations suggest that SSEs and associated slow earthquake phenomena are promoted by lithological, mechanical, and frictional heterogeneity within the fault zone, enhanced by geometric complexity associated with subduction of rough crust., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)
Published: 2020
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45. Mariana serpentinite mud volcanism exhumes subducted seamount materials: implications for the origin of life.

Author: Fryer P, Wheat CG, Williams T, Kelley C, Johnson K, Ryan J, Kurz W, Shervais J, Albers E, Bekins B, Debret B, Deng J, Dong Y, Eickenbusch P, Frery E, Ichiyama Y, Johnston R, Kevorkian R, Magalhaes V, Mantovanelli S, Menapace W, Menzies C, Michibayashi K, Moyer C, Mullane K, Park JW, Price R, Sissmann O, Suzuki S, Takai K, Walter B, Zhang R, Amon D, Glickson D, and Pomponi S
Subjects: Minerals chemistry, Origin of Life, Seawater chemistry, Volcanic Eruptions
Abstract: The subduction of seamounts and ridge features at convergent plate boundaries plays an important role in the deformation of the overriding plate and influences geochemical cycling and associated biological processes. Active serpentinization of forearc mantle and serpentinite mud volcanism on the Mariana forearc (between the trench and active volcanic arc) provides windows on subduction processes. Here, we present (1) the first observation of an extensive exposure of an undeformed Cretaceous seamount currently being subducted at the Mariana Trench inner slope; (2) vertical deformation of the forearc region related to subduction of Pacific Plate seamounts and thickened crust; (3) recovered Ocean Drilling Program and International Ocean Discovery Program cores of serpentinite mudflows that confirm exhumation of various Pacific Plate lithologies, including subducted reef limestone; (4) petrologic, geochemical and paleontological data from the cores that show that Pacific Plate seamount exhumation covers greater spatial and temporal extents; (5) the inference that microbial communities associated with serpentinite mud volcanism may also be exhumed from the subducted plate seafloor and/or seamounts; and (6) the implications for effects of these processes with regard to evolution of life. This article is part of a discussion meeting issue 'Serpentine in the Earth system'.
Published: 2020
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46. On impact and volcanism across the Cretaceous-Paleogene boundary.

Author: Hull PM, Bornemann A, Penman DE, Henehan MJ, Norris RD, Wilson PA, Blum P, Alegret L, Batenburg SJ, Bown PR, Bralower TJ, Cournede C, Deutsch A, Donner B, Friedrich O, Jehle S, Kim H, Kroon D, Lippert PC, Loroch D, Moebius I, Moriya K, Peppe DJ, Ravizza GE, Röhl U, Schueth JD, Sepúlveda J, Sexton PF, Sibert EC, Śliwińska KK, Summons RE, Thomas E, Westerhold T, Whiteside JH, Yamaguchi T, and Zachos JC
Subjects: Carbon Dioxide analysis, Global Warming, Mexico, Models, Theoretical, Carbon Cycle, Extinction, Biological, Volcanic Eruptions
Abstract: The cause of the end-Cretaceous mass extinction is vigorously debated, owing to the occurrence of a very large bolide impact and flood basalt volcanism near the boundary. Disentangling their relative importance is complicated by uncertainty regarding kill mechanisms and the relative timing of volcanogenic outgassing, impact, and extinction. We used carbon cycle modeling and paleotemperature records to constrain the timing of volcanogenic outgassing. We found support for major outgassing beginning and ending distinctly before the impact, with only the impact coinciding with mass extinction and biologically amplified carbon cycle change. Our models show that these extinction-related carbon cycle changes would have allowed the ocean to absorb massive amounts of carbon dioxide, thus limiting the global warming otherwise expected from postextinction volcanism., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)
Published: 2020
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47. Abiotic synthesis of graphite in hydrothermal vents.

Author: Estes ER, Berti D, Coffey NR, Hochella MF Jr, Wozniak AS, and Luther GW 3rd
Abstract: Deciphering the origin, age, and composition of deep marine organic carbon remains a challenge in understanding the dynamics of the marine carbon cycle. In particular, the composition of aged organic carbon and what allows its persistence in the deep ocean and in sediment is unresolved. Here, we observe that both high and low temperature hydrothermal vents at the 9° 50' N; 104° 17.5 W East Pacific Rise (EPR) vent field are a source for (sub)micron-sized graphite particles. We demonstrate that commonly applied analytical techniques for quantification of organic carbon detect graphite. These analyses thereby classify graphite as either dissolved or particulate organic carbon, depending on the particle size and filtration method, and overlook its relevance as a carbon source to the deep ocean. Settling velocity calculations indicate the potential for these (sub)micron particles to become entrained in the buoyant plume and distributed far from the vent fields. Thus, our observations provide direct evidence for hydrothermal vents acting as a source of old carbon to the deep ocean.
Published: 2019
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48. Dataset of characteristic remanent magnetization and magnetic properties of early Pliocene sediments from IODP Site U1467 (Maldives platform).

Author: Lanci L, Zanella E, Jovane L, Galeotti S, Alonso-García M, Alvarez-Zarikian CA, Bejugam NN, Betzler C, Bialik OM, Blättler CL, Eberli GP, Guo JA, Haffen S, Horozal S, Inoue M, Kroon D, Laya JC, Hui Mee AL, Lüdmann T, Nakakuni M, Niino K, Petruny LM, Pratiwi SD, Reijmer JJG, Reolid J, Slagle AL, Sloss CR, Su X, Swart PK, Wright JD, Yao Z, and Young JR
Abstract: This data article describes data of magnetic stratigraphy and anisotropy of isothermal remanent magnetization (AIRM) from "Magnetic properties of early Pliocene sediments from IODP Site U1467 (Maldives platform) reveal changes in the monsoon system" [1]. Acquisition of isothermal magnetization on pilot samples and anisotropy of isothermal remanent magnetization are reported as raw data; magnetostratigraphic data are reported as characteristic magnetization (ChRM)., (© 2019 The Authors. Published by Elsevier Inc.)
Published: 2019
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49. The affiliation of Hexasterias problematica and Halodinium verrucatum sp. nov. to ciliate cysts based on molecular phylogeny and cyst wall composition.

Author: Gurdebeke PR, Mertens KN, Takano Y, Yamaguchi A, Bogus K, Dunthorn M, Matsuoka K, Vrielinck H, and Louwye S
Subjects: DNA, Ribosomal genetics, Geologic Sediments parasitology, Parasite Encystment, Species Specificity, Ciliophora classification, Ciliophora genetics, Phylogeny
Abstract: Species in the genera Hexasterias and Halodinium have been recorded over the last decades as acritarchs in palynological and/or plankton studies. In paleoenvironmental studies, these resting stages are often interpreted as indicators of freshwater input. The biological affinity of these genera has never been definitely established. Here, a new species, Halodinium verrucatum sp. nov., is described and molecular evidence (single specimen SSU and LSU rDNA sequencing) reveals that both this new species and Hexasterias problematica, collected from sediment samples in the Skagerrak and Baltic Sea, are resting stages of prorodontid ciliates. Additionally, infrared spectroscopic analysis (micro-FTIR) of Hexasterias problematica and Halodinium spp. specimens indicates a carbohydrate-based composition of the cyst wall with evidence for nitrogen-containing functional groups. A similar composition is recorded for tintinnid loricae, which further supports the placement of Hexasterias and Halodinium as ciliate cysts, and the composition is consistent with the heterotrophic nature of ciliates. The morphologically similar species Radiosperma corbiferum has a comparable composition, suggesting a similar ciliate affinity and indicating the utility of micro-FTIR in understanding acritarch affinity. Hexasterias problematica typically occurs in coastal waters from temperate to arctic regions. Halodinium verrucatum sp. nov. is observed in temperate estuarine sediments in the northern hemisphere., (Copyright © 2018 Elsevier GmbH. All rights reserved.)
Published: 2018
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50. Paleomagnetism of IODP Site U1380: Implications for the Forearc Deformation in the Costa Rican Erosive Convergent Margin.

Author: Li YX, Zhao X, Xie S, Jovane L, and Petronotis K
Abstract: The destructive nature of subduction erosion poses challenges to fully understanding the evolution of erosive convergent margins that are critical to understanding crustal recycling and seismogenesis. Forearc deformation holds important clues to the evolution of erosive convergent margins. Here we present detailed paleomagnetic and structural analyses of IODP Site U1380 cores from the middle slope of the forearc of the Costa Rican erosive convergent margin. The analyses reveal a strong deformation zone from ~490 to ~550 mbsf that is characterized by abundant fissility/foliations shallower than the bedding. Similar relatively strong deformation zones are recognized from the frontal prism and upper slope sites, and are broadly correlative, forming a zone of strong deformation across the forearc. This zone spans ~2.0 to 1.83 Ma and the deformation likely occurred briefly at ~1.80 Ma. The widespread, short-lived, and strong deformation is interpreted as a result of intense subhorizontal shear following the rapid forearc subsidence driven by the dramatic subduction erosion associated with the abrupt onset of the Cocos Ridge subduction. Given the typical occurrence of forearc subsidence by subduction erosion, similar styles of deformation are probably common in other erosive convergent margins as well.
Published: 2018
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