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Of Cenozoic age, the Fossong-Wentcheng trachytic dome is located on the southwestern slope of Mount Bambouto. It was probably emplaced during the second period of activity (between 18.5 and 15.3 Ma) of the Mount Bambouto, within the Pan-African granitic basement rock. The dome shows aphyric and porphyritic textures with crystals such as sanidine, clinopyroxene, and oxides. These oxides may be magnetite due to the dominant ferromagnetic behavior of the rock. The dominance of planar AMS ellipsoids and low Pj values reflect the high viscosity of the magma that sets up the Fossong-Wentcheng trachytic dome. The magnetic fabric (foliation and lineation) displays roughly sub-circular trends in the central and the northern parts of the dome with the feeder zone located on its southern part where they display fabrics in the NE-SW direction with steep dips and plunges. This implies that the magma rose through a NE-SW–directed fracture in the basement granitic rock before its propagation towards the NNW-SSE direction by developing one lobe flow emplacement. [ABSTRACT FROM AUTHOR]

Elucidating the geologic history of the Greenland Ice Sheet (GrIS) is essential for understanding glacial instability thresholds, identified as major climate system tipping points, and how the cryosphere will respond to anthropogenic greenhouse gas emissions. To address current knowledge gaps in the evolution and variability of the GrIS and its role in Earth's climate system, International Ocean Discovery Program (IODP) Expedition 400 obtained sedimentary records from Sites U1603-U1608 across the northwest Greenland margin into Baffin Bay where thick Cenozoic sedimentary successions can be directly linked to the evolution of the northern GrIS (NGrIS). The strategy of drilling along this transect was to retrieve a composite stratigraphic succession representing the late Cenozoic era from the Oligocene/early Miocene to Holocene. The proposed sites targeted high-accumulation rate deposits associated with contourite drifts and potential interglacial deposits within a trough mouth fan system densely covered by seismic data. The principal objectives were to (1) test if the NGrIS underwent near-complete deglaciations in the Pleistocene and assess the ice sheet's response to changes in orbital cyclicities through the mid-Pleistocene transition; (2) ascertain the timing of the NGrIS expansion and examine a hypothesized linkage between marine heat transport through Baffin Bay and high Arctic warmth during the Pliocene; and (3) provide new understandings of climate-ecosystem conditions in Greenland during the geologic periods with increased atmospheric CO2 compared to preindustrial values, encompassing the last 30 My. The deep time objective was attained by coring at Site U1607 on the inner shelf to 978 meters below seafloor, capturing a succession of mainly Miocene and Oligocene age. The six sites drilled during Expedition 400 resulted in 2299 m of recovered core material, and wireline downhole logging was completed at Sites U1603, U1604, U1607, and U1608. This unique archive will provide the basis for understanding the full range of forcings and feedbacks--oceanic, atmospheric, orbital, and tectonic--that influence the GrIS over a range of timescales, as well as conditions prevailing at the time of glacial inception and deglacial to interglacial periods. We anticipate that the shipboard data and further analytical work on Expedition 400 material can constrain predictive models addressing the GrIS response to global warming and its impending effects on global sea levels. [ABSTRACT FROM AUTHOR]

Summary: The macroevolutionary processes that have shaped biodiversity across the temperate realm remain poorly understood and may have resulted from evolutionary dynamics related to diversification rates, dispersal rates, and colonization times, closely coupled with Cenozoic climate change.We integrated phylogenomic, environmental ordination, and macroevolutionary analyses for the cosmopolitan angiosperm family Rhamnaceae to disentangle the evolutionary processes that have contributed to high species diversity within and across temperate biomes.Our results show independent colonization of environmentally similar but geographically separated temperate regions mainly during the Oligocene, consistent with the global expansion of temperate biomes. High global, regional, and local temperate diversity was the result of high in situ diversification rates, rather than high immigration rates or accumulation time, except for Southern China, which was colonized much earlier than the other regions. The relatively common lineage dispersals out of temperate hotspots highlight strong source‐sink dynamics across the cosmopolitan distribution of Rhamnaceae.The proliferation of temperate environments since the Oligocene may have provided the ecological opportunity for rapid in situ diversification of Rhamnaceae across the temperate realm. Our study illustrates the importance of high in situ diversification rates for the establishment of modern temperate biomes and biodiversity hotspots across spatial scales. [ABSTRACT FROM AUTHOR]

Introduction: The Panyu low uplift is located in the middle of the Central Uplift Belt of the Pearl River Mouth Basin, which has experienced multiple episodes of tectonic movements since the Cenozoic, and the faults are extensively developed there. The fault activities had a significant influence on the migration and accumulation of oil and gas, as well as the sedimentation. Methods: In order to recognize the effect of the faults on the tectono-straigraphy evolution in the Panyu low uplift, based on the high-resolution seismic and latest drilling well data, the study has comprehensively analyzed the geometry and kinematics of these faults, as well as the sedimentary filling evolution of the residual depressions. Results: The results show that two major fault systems has developed in the Panyu low uplift: the deep and shallow fault systems. The former was dominated by a series of NEE and NW-trending high-angle listric/plane faults, along with several low-angle detachment normal faults, which were under the joint control of the NW-SE and NS-trending extensional stress during the Eocene. The latter was dominated by NW-NWW trending strike-slip normal faults with tension-shear properties under the NEE trending dextral strike-slip stress field in the late Miocene. The uplift had undergone five tectonic evolution stages: the initial rifting stage (Tg-T83), the intensive rifting stage (T83-T80), the rifting and depression transitional stage (T80-T70), the thermal subsidence depression stage (T70-T35), and the tectonic reactivation stage (T35-T10). Discussion: Based on the 3D seismic phase interpretation and drilling sample analyses, the study also indicates that during the initial rifting stage, the Panyu low uplift manifested as multistage depositional center. The sedimentary strata were distributed in the downthrown wall of the depression-controlling faults, exhibiting multiple subsidence and sedimentary centers, and the depressions was supplied by multi-provenance systems. During the intense rifting period, the depression widened, the lacustrine basins were connected with each other, and the sedimentary center migrated. During the rifting and depression transitional stage, the faults controlling on deposition weakened. The thick Enping formation from the northwest provenance direction is unconformably overlaid on the Panyu low uplift. Meanwhile, the depressions was characterized by the sedimentary deposits of lacustrine basin. Various types of sedimentary facies were developed, including the delta, semi-deep lacustrine, shallow lacustrine, and shore-shallow lacustrine deposits, and the mudstone of the semi-deep lacustrine facies could serve as a high-quality source rock for the hydrocarbon production. [ABSTRACT FROM AUTHOR]

Theria represent an extant clade that comprises placental and marsupial mammals. Here we report on the discovery of a new Late Cretaceous mammal from southern Patagonia, Patagomaia chainko gen. et sp. nov., represented by hindlimb and pelvic elements with unambiguous therian features. We estimate Patagomaia chainko attained a body mass of 14 kg, which is considerably greater than the 5 kg maximum body mass of coeval Laurasian therians. This new discovery demonstrates that Gondwanan therian mammals acquired large body size by the Late Cretaceous, preceding their Laurasian relatives, which remained small-bodied until the beginning of the Cenozoic. Patagomaia supports the view that the Southern Hemisphere was a cradle for the evolution of modern mammalian clades, alongside non-therian extinct groups such as meridiolestidans, gondwanatherians and monotremes. [ABSTRACT FROM AUTHOR]

In Western Thailand, Miocene shales from Wang Kaew, in the Mae Sot basin, have yielded a diverse insect assemblage comprising 115 articulated specimens. In this preliminary review, 15 subcomplete specimens are studied and referred to at least eight forms belonging to five orders (Coleoptera, Diptera, Hymenoptera, Orthoptera, and Hemiptera). Coleoptera are represented by very nicely preserved specimens of weevils (Curculionidae). Diptera are known by three different taxa referred to Bibionidae, Sciaridae and Brachycera. Hymenoptera are known by representatives of Vespidae and Formicidae. Orthoptera are represented by a single specimen of uncertain affinities and Hemiptera by one Gerrinae. This insect assemblage is the most complete ever reported in Southeast Asia during the Cenozoic. [ABSTRACT FROM AUTHOR]

The relationship between deep crustal structure and the deformation in the overlying sedimentary wedge in Santos basin, Brazil is not well understood, and the origin and evolution of the salt‐related "Albian Gap (AG)" remain a topic of debate. We investigate the deep structure using three‐dimensional inversion of full tensor marine magnetotelluric (MT) data (of 10−1 to 104 s period bandwidth) from 92 stations along three NW–SE lines in 50–1,700 m water depth, one crossing the Cretaceous hinge line (CHL), AG, and Cabo Frio Fault (CFF). The geological validity of the resulting MT resistivity models was determined using resistivity logs from 11 wells and seismic data. The model shows two regionally persistent electrically conductive layers (C2 and C3) related to key Cenozoic and Cretaceous unconformities in the upper part of the sedimentary wedge. Beneath this wedge, the resistive continental crust is ∼35 km thick across the CHL until the 200 m isobath and thereafter thins rapidly seaward to ∼21 km over a lateral distance of ∼80 km defining a domain of highly extended and faulted crust. Our models show a mantle‐associated basement high and evidence of significant uplift of the lower part of the sedimentary wedge at 100–150 km distance along our central profile which spatially coincides with the AG and a previously proposed Moho high. This implies a mantle‐driven deformation of the crust and basin fill. We propose that mantle flow and magmatism may have played a significant role in the inferred displacement at the AG. Plain Language Summary: How the deformation observed in the sedimentary wedge of Santos basin, Brazil is related to deep crustal and/or upper mantle processes is not well understood. We investigate the deep structure beneath Santos basin using a three‐dimensional magnetotelluric resistivity model crossing the Cretaceous hinge line (CHL), Albian Gap (AG), and Cabo Frio Fault (CFF). The geology‐calibrated resistivity model shows a top electrically conductive sedimentary wedge, underlain by the resistive crust that thins seawards as a result of basin evolution through continental rifting and extension characteristic of passive margin basins. The resistive continental crust is ∼35 km thick across the CHL and thins rapidly seaward to ∼21 km beneath the CFF, defining a domain of ∼80 km with highly extended and faulted crust. Our model suggests a mantle‐associated basement high and shows evidence of significant displacement over a wide zone across a proposed Moho high and the AG implying a coupled deformation of the basement and the sedimentary wedge. It is proposed that magmatism or lower crustal flow may have played a significant role in the inferred significant dislocation of strata at the AG. Key Points: Electrically resistive continental crust is ∼35 km thick near‐shore and thins rapidly seaward to about 21 km over a distance of ∼80 kmResistivity models show a 50 km wide zone of heavily faulted thin crust and shallow mantle that is spatially coincident with the Albian Gap (AG)We propose that the vertical movement and the enigma of the AG may be related to mantle‐driven uplift and magmatism in this zone of highly extended crust [ABSTRACT FROM AUTHOR]

Rheological layering of the tectonosphere of the South China Sea (SCS) on the crust—rigid (the depth interval of 5–30 km), viscous subcrustal (the depth interval of 30–70 km), rigid lower lithospheric (50–90 km), astenospheric (80–150 km) and rigid subastenospheric (the depth interval is more than 150 km)—is established. Distributions of the density inhomogeneities related to the main tectonic events in the SCS are caused by the Paleo-Pacific's convergence, and later, the oceanic Philippine Plate, with the Philippine archipelago and later, with the Asian margin. In this zone, based on density contrast distributions in the tectonosphere, Cenozoic processes of a subduction, stretching, transform shift and structure of the central type of the probable plume nature are traced, which form an evolutionary sequence: back-arc, or paleoceanic spreading → Philippine subduction → NE-stretching with discplacement → formation of a central type of structure, probably with a plume origin. The structures caused by convergence of the Asian continent with the Indo-Australian Plate are isolated from the West Pacific margin, and underthrusting of rigid lithospheric plates from the south under the lithosphere of the marginal sea reflects traces of a more ancient collision of fragments of Gondwana with the Asian continent. [ABSTRACT FROM AUTHOR]

This report analyzes original geological materials on the Magellan Seamounts in the Pacific Ocean, obtained by the authors on numerous cruises of the R/V Gelendzhik. This chain of guyouts does not have a common volcanic basement and apparently formed in the second half of the Early Cretaceous on the oldest (Middle–Late Jurassic) fragment of the Pacific Plate. The main viewpoints on the genesis of the Magellan Seamounts are as follows: either they originated at the intersection of fracture zones or the Pacific Plate moved them from the Southern Hemisphere to their present-day position. Because of their high degree of study, the Magellan Seamounts are one of the key sites for understanding the mechanism underlying the origin of linear chains in the ocean. A comprehensive analysis of new geological data on the Magellan Seamounts has established the important role of magmatism and tectonics in the formation of the modern morphological forms, sedimentation, and influence on the paleoceangraphy. The periodic reactivation of these processes from the Early Cretaceous to Late Cenozoic can be traced in the cyclicity of sedimentation, the continuous growth of ore crusts, and the formation of secondary volcanic domes and cones. [ABSTRACT FROM AUTHOR]

Original analytical data on trace elements and radiogenic Nd and Pb isotopes in the volcanic rocks of the Southern and southwestern part of the Northern plateaus of the underwater Vityaz Ridge are presented. Interpretation of these data and a comparison with published materials on the volcanic rocks from the southern and northern parts of the Kuril Island Arc (KIA), which formed on two basement blocks of different genetic nature, allow us to draw the following conclusions. The tholeiite varieties of volcanic rocks of the Southern Plateau and the southern part of the KIA have similar isotope-geochemical features, which point to the similar geodynamic conditions of the formation and the identical influence of low-temperature fluid on magma-generating processes. The geochemistry of the volcanic rocks of the Northern Plateau, which are mainly represented by subalkaline varieties, indicates a more pronounced contribution of the mantle component to the magmagenesis and a greater degree of influence of high-temperature melt compared to the rocks of the Southern Plateau, but a lesser degree compared to the rocks of the northern part of the arc. The volcanics of both plateaus are derivatives of a single mantle source, the MORB of the Indian Ocean (Indian MORB), and were formed together with the rocks of the southern part of the KIA within the lithospheric block transformed by tectonomagmatic processes that accompanied the opening of the Kuril Basin. [ABSTRACT FROM AUTHOR]

The structural features of rifting are reviewed during the formation of Cenozoic basins of the Western Pacific marginal seas. The examples of studied basins confirmed a hypothesis that rifting always starts from a passive phase and is only interrupted by episodes of active rifting. Rifting occurred under NE- and NNE-trending horizontal compression with the formation of either a chain of pull-apart basins or fields of diffuse rifting between the large strike-slip faults (the main part of the South China Sea). The NE and NNE directions of horizontal compression are probably related to the upper mantle convective flows from a spreading ridge of the Indian Ocean, which bear the plate fragments variously deformed during the transportation. The related NNE drift of the Indian, Australian, and Eurasian plates has no link with subduction processes from adjacent Paleopacific plates, which continue to move to northwest. The Western Pacific marginal basins mainly formed without any subduction influence from the Pacific Ocean and can be called backarc basins only based on geographical features. [ABSTRACT FROM AUTHOR]

The Ordos Basin is rich in oil and gas resources in the Paleozoic strata. The southern part of the basin boasts a thick Paleozoic sedimentary sequence, enriched organic matter, favorable sedimentary facies, and hydrocarbon source rocks with an over-mature thermal evolution stage. However, the lack of in-depth study of the tectono-thermal evolution in the southern basin limits regional oil and gas exploration. In this study, drill core and outcrop samples were collected from the Shanbei Slope and the Weibei Uplift, respectively. These samples were subjected to apatite fission track (AFT) and (U-Th)/He dating (AHe). The results were used to reconstruct the thermal history of the southern basin, calculate exhumation rates, and analyze the tectonic evolution of the basin. The seven annealed AFT data values from the Shanbei Slope range from 21.4 to 52.8 Ma, with mean track lengths of 13.24 μm, and the twelve unannealed AFT data values from the Weibei Uplift range from 111.9 to 204.6 Ma. The seven AHe data values from the Shanbei Slope range from 17.0 to 31.8 Ma, and the eight AHe data values from the Weibei Uplift range from 31.7 to 47.5 Ma. The thermal history is characterized by a prolonged phase of burial and heating from the Triassic to the Late Early Cretaceous, followed by a phase of uplift and cooling that continued into the Cenozoic. This cooling phase exhibits three distinct stages with varying rates of uplift and cooling. According to the dating results, the cooling timing of the southern basin was earlier than that of the central part, and the southern basin experienced higher uplift rates during the Paleogene than in other periods of the Cenozoic. This may be attributed to the far-field effects of the collision between the Indian Plate and the Eurasian Plate during the Paleogene. [ABSTRACT FROM AUTHOR]

The Longshou Shan, located in western China, plays a crucial role in connecting the Tarim Continent with the North China Craton. It provides valuable insights into the Cenozoic intracontinental deformation, the complex dynamics of Eurasian tectonics, and the relationship between the pre-Cenozoic Tethys and Central Asian orogenic systems. Consequently, comprehending the evolution of the Phanerozoic era in this region holds immense significance. Zircon (U-Th)/He (ZHe) dating was conducted on three granite samples (n = 18) collected from the Longshou Shan. The ZHe dates of these granite rocks range from 7.2 to 517.7 Ma, showing a negative correlation with eU values. Furthermore, a limestone sample from the Longshou Shan yielded ZHe (n = 4) ages of 172.0–277.1 Ma and AHe (n = 4) ages of 17–111.9 Ma. The area has undergone complex tectonic processes involving multiple phases of uplift and burial. Using both forward and inverse modeling methods, we aim to establish plausible thermal histories. Our models reveal: (1) Late Paleozoic unroofing; (2) Early Mesozoic cooling and Late Mesozoic regional stabilization; and (3) Cenozoic reheating and subsequent cooling. By investigating the intricate thermal history of the Longshou Shan through multi-method modeling, we compare different approaches and assess the capabilities of single ZHe dating for understanding a thermal history. This research contributes to unraveling the region's geological complexities and aids in evaluating various modeling methods. [ABSTRACT FROM AUTHOR]

Diversification of woody plant lineages in New Zealand has unfolded in complex physiographic, climatic, and environmental contexts. Many tree and shrub lineages have existed in New Zealand since the late Cenozoic when Forest was the dominant biome, subsequently diversifying (or continuing to diversify) during the Pliocene/Pleistocene as Open (below treeline) and Alpine biomes emerged. We examine the links between biomes occupied, traits, and diversification. In particular, whether traits are phylogenetically conserved or ecologically constrained and their relationship to biomes occupied. We focus on Melicytus, Myrsine and Pseudopanax which occur across Forest, Open, and Alpine biomes. Our approach combines measured traits and modelled niche traits of extant species to examine the importance of biome occupancy and biome shifts on trait evolution in these lineages. Our results demonstrate trait values are filtered by biomes in these lineages and can predict biomes occupied. However, few biome shifts were associated with trait evolution, typically only biome shifts into extreme environments (Alpine) involved trait innovations. In addition to biomes, trait evolution can also be influenced by species age, trait lability and broad climatic change. Integrating functional traits in a phylogenetic framework can identify how evolutionary and ecological features create modern biogeographic patterns in New Zealand. [ABSTRACT FROM AUTHOR]

This study presents results from apatite fission track (AFT) thermochronology to investigate the thermal history and exhumation dynamics of the Rio Negro–Juruena basement, situated within the western Guiana Shield of the Amazonian Craton. AFT dating and associated thermal history modeling in South America has largely been restricted to the plate's margins (e.g., Andean active margin, Brazilian passive margin, and others). Our paper reports on low-temperature thermochronological data from the internal part of the western Guiana Shield for the first time. This area is part of a vast cratonic lithosphere that is generally thought to be stable and little influenced by Mesozoic and Cenozoic tectonics. Our data, however, show AFT central ages ranging from 79.1 ± 3.2 to 177.1 ± 14.8 Ma, with mean confined track lengths of ca. 12 µm. Contrary to what might be expected of stable cratonic shields, inverse thermal history modeling indicates a rapid basement cooling event in the early Cretaceous. This cooling is interpreted as a significant exhumation event of the basement that was likely driven by the coeval extensional tectonics associated with back-arc rifts in the Llanos and Putumayo–Oriente–Maranon basins. The extensional tectonics facilitated both basement uplift and subsidence of the adjoining basins, increasing erosional dynamics and consequent exhumation of the basement rocks. The tectonic setting shifted in the late Cretaceous from extensional to contractional, resulting in reduced subsidence of the basins and consequential diminishing cooling rates of the Guiana Shield basement. Throughout the Cenozoic, only gradual, slow subsidence occurred in the study area due to regional flexure linked to the Andean orogeny. Comparative analysis with low-temperature thermochronology data from other west Gondwana cratonic segments highlights that exhumation episodes are highly controlled by tectonic inheritance, lithospheric strength, and proximity to rift zones. This study underscores the complex interplay between tectonic events and the response of cratonic lithosphere over geological timescales and highlights extensional settings as an important geological context for craton exhumation. [ABSTRACT FROM AUTHOR]

The knowledge of the residence time of formation water is fundamental to understanding the subsurface flow and hydrological setting. To better identify the origin and evolution of coal seam water and its impact on gas storage and production, this study collected coalbed methane co‐produced water in the southeast Qinshui Basin and detected chemical and isotopic compositions, especially 36Cl and 129I concentrations. The calculated tracer ages of 129I (5.2–50.6 Ma) and 36Cl (0.13–0.76 Ma) are significantly younger than the age of coal‐bearing formation (Pennsylvanian ‐ Cisuralian), indicating freshwater recharge after coal deposition. The model that utilises 129I/I and 36Cl/Cl ratios to constrain the timing of recharge and the proportion of recharge water reveals that over 60% of pre‐anthropogenic meteoric water entered coal seams since 10 Ma and mixed with residue initial deposition water, corresponding to the basin inversion in Cenozoic. The spatial distribution of major ion concentrations reveals the primary recharge pathway for meteoric water from coal outcrops at the eastern margin to the basin center. This study demonstrates the occurrence of higher gas production rates from wells that accept water recharge in recent times and suggests the possible potential of the non‐stagnant zones for high gas production. [ABSTRACT FROM AUTHOR]

The Linxia Basin is characterized by an abundance of Cenozoic sediments, that contain exceptionally rich fossil resources. Equids are abundant in the Linxia Basin, the fossil record of equids in this region including 16 species that represent 10 genera. In comparison to other classic late Cenozoic areas in China, the Linxia Basin stands out, because the fauna and chronological data accompanying Linxia equids render them remarkably useful for biostratigraphy. The anchitheriines in the region, such as Anchitherium and Sinohippus, represent early equids that appeared in the late stages of the middle and late Miocene, respectively. Among the equines, most species of Chinese hipparions have been identified in the Linxia Basin and some species of the genera Hipparion and Hippotherium have FAD records for China. Furthermore, Equus eisenmannae is one of the earliest known species of Equus in the Old World and is well‐represented at the Longdan locality. Some species with precise geohistorical distributions can serve as standards for high‐resolution chronological units within this framework. Located at the eastern margin of the Tibetan Plateau and subject to considerable uplift, the Linxia Basin has served as a biogeographic transition area for equids throughout the late Cenozoic. [ABSTRACT FROM AUTHOR]

The Cenozoic sediments are very thick in the southwest Tarim Basin and very thin in the northwest, but what controls these variations is unclear. Here, we use two‐dimensional thermo‐mechanical models to investigate how the lateral variations in rheological strength and depletion density of cratonic lithosphere mantle affect the cratonic basin deformation. Model results show that the basin basement uplift occurs above either the region with crustal thickening or high depletion in the mantle. A model with a stronger and density‐depleted northern half of cratonic lithosphere mantle in the context of compression matches the differential Cenozoic subsidence and deformation observed in the Tarim Basin well. We propose that a Permian plume led to the lateral heterogeneity of the lithosphere mantle under the Tarim craton, and the modified lithosphere mantle characteristics caused the differential Cenozoic sediment thickness in the Tarim Basin. Plain Language Summary: Tarim Basin is a typical intraplate cratonic basin in northwest China. It is bounded by the West Kunlun Shan to the south and the Tian Shan to the north, respectively. The Cenozoic sediment thickness in the Tarim Basin displays significant lateral variation, which cannot be explained by flexural bending of the Tarim lithosphere under orogenic loads of the West Kunlun Shan and Tian Shan. Recent geophysical data outlined the extent of the Permian plume head, which coincides with the region covered by thinnest Cenozoic sediments. Here, we conduct a series of 2‐D thermo‐mechanical numerical simulations to examine the correlation of the cratonic lithosphere mantle characteristics with cratonic basin's basement geometry. Model results show that a craton with a stronger and density‐depleted northern half of lithosphere mantle in the context of compression matches well with the south‐north differential Cenozoic subsidence and deformation in the Tarim Basin. Accordingly, we suggest that the differential Cenozoic sediment thickness in the Tarim Basin was likely caused by the Permian plume‐modified lithosphere mantle. Our study indicates that the plume‐modified mantle characteristics play a critical role in the basement deformation of the above sediment basin. Key Points: The strength and depletion density of cratonic lithosphere mantle control the deformation of cratonic lithosphere underlying sediment basinThe differential Cenozoic sediment thickness in the Tarim Basin is related to the heterogeneity of cratonic lithosphere mantleThe lithosphere mantle heterogeneity under the Tarim craton was likely caused by post‐Permian plume‐driven recratonization [ABSTRACT FROM AUTHOR]

A broad region of Mesozoic to Cenozoic tectonism along the western and central Circum-Mediterranean (CM) margins, from southern Spain (Betic Cordillera) to the northern Morocco (Rif) and Italy (Apennines), includes huge volumes of sedimentary record since the Late Paleozoic. These sediments are contemporaneous and related with the fragmentation of the Pangean supercontinent due to the rifting and progressive closure, as well as the following birth of the CM orogeny. The composition and stratigraphic relations of clastics in diverse sedimentary basins of the CM region reflect a complete record of provenance relations related to the progressive destruction of the Neotethyan Ocean and plate convergence between the two major plates of Europe and Africa, and Iberia, Adria and Mesomediterranean micrplates located between them. The changing nature of clastic wedges reflects the provenance relations from different source rocks involving obduction of the oceanic lithosphere, the uplifted Alpine-Mediterranean Chains, and the accreted previously deformed Mesomediterranean Microplate (AlKaPeCa), as well local neovolcanic sources, within the spatial and temporal evolving geo-puzzle terranes of the CM orogeny. The provenance evolution of sediment provides insights into how plate convergence and continental collision direct the sediment dispersal pathway in Cenozoic basins due to closure of eastern and southern Alpine-Tethyan remnant ocean basins and to the dual dispersal pathways from the previously born Alps and the nascent AlKaPeCa at the expenses of the previously deformed Mesomediterranean terranes. The source-to-sink relations testify episodic deformation events, diachronous Tethyan basin development, differentiate sediment provenance from exhumed and uplifted Alpine and CM orogens, and palaeogeographic rearrangement of crustal blocks along the nascent Mediterranean region. [ABSTRACT FROM AUTHOR]

Liquidambar L. is a significant constituent of the Cenozoic flora in the Northern Hemisphere. Currently, this genus exhibits a discontinuous distribution across Asia and North America, with the center of diversity being in southeastern Asia. This study presents the first occurrence of Liquidambar in the Oligocene of South China. Fossil sweetgum infructescences, associated pollen, and leaves have been found in the Nanning Basin, Guangxi. A new species, Liquidambar nanningensis sp. nov., is described based on the morphological and anatomical characteristics of three-dimensionally preserved infructescences. The Liquidambar fossils from the Nanning Basin show a combination of features indicative of the former genera of Altingiaceae, Altingia, Liquidambar s. str., and Semiliquidambar. The new occurrence expands the taxonomic and morphological diversity of the Paleogene Liquidambar species in South China. [ABSTRACT FROM AUTHOR]

Despite being essential in determining absolute paleomagnetic field intensity (API) with high fidelity over Earth science research topics, API determination still suffers little quantitative success. This is due to common nonideal magnetic behaviors in experiments using natural rocks caused by physiochemical changes in the magnetic minerals contained. Although linking rock-magnetic parameters to API results may be fundamental, negligible effort has been made using the Tsunakawa–Shaw (TS) API method despite its potentially high experimental success rate in overcoming nonideal magnetic effects. Here, we explore the relationships between rock-magnetic parameters retrieved using relatively rapid and widely pre-conducted measurements and TS API results from late Cenozoic basaltic rocks. We selected rock-magnetic parameters quantified from strong-field high-temperature thermomagnetic curves, magnetic hysteresis loops, and back-field isothermal remanent magnetization demagnetizations. We provide new data pairs of rock-magnetic parameters and TS API results for 41 basaltic rock samples from 8 sites (cooling units) in Northeast China. Then, by compiling them with published data of similar quality, we compiled 133 pairs of rock-magnetic and TS API data at the sample level (38 sites). Using this data compilation, the following topics of interest were identified: Magnetic coercivity (Bc) and remanence coercivity (Bcr) among the hysteresis parameters, and the thermomagnetic parameter ITC|m| (an index of thermal change quantifying an average of the differences in saturation magnetization at a full temperature range of during a single heating–cooling run) allow meaningful and efficient discrimination between data subsets divided by "success" or "failure" in the API results. We propose sample preselection criteria for the TS experiment: a minimal set of Bc ≥ 13 mT (or Bcr ≥ 26 mT) and ITC|m|≤ 0.15. Moreover, extended consideration based on the preselection criteria may allow the screening of potentially biased specimen/sample-level API estimates in the site-averaged determination of such a site with a large within-site API dispersion. [ABSTRACT FROM AUTHOR]

Global weathering is a primary control of the earth's climate over geologic time scales: converting atmospheric pCO2 into dissolved bicarbonate; with carbon sequestration by marine plankton as carbonate and organic carbon on the ocean floor. The accumulation rate of pelagic marine biogenic sediments are thus a measure of weathering history. Previous studies of Cenozoic pelagic sedimentation have yielded contrasting results, though most show a dramatic rise (up to 6 times) in rates over the Cenozoic. This contrasts with model expectations for approximate steady state in weathering, pCO2, and sequestration over time. Here we show that the Cenozoic record of sedimentation recovered by deep sea drilling has a strong, systematic bias towards lower rates of sedimentation with increasing age. When this bias is removed accumulation rates are shown to actually decline by ca 2 times over the Cenozoic. When accumulation area however is adjusted for changes in available deposition area, global weathering is shown to have nearly doubled at the Eocene-Oligocene boundary, but was otherwise essentially constant. Compilations of other metrics correlated to sedimentation rate (e.g. productivity, biotic composition) also must have a strong age bias, which will need to be considered in future paleoceanographic studies. [ABSTRACT FROM AUTHOR]

The regionally prominent main boundary thrust (MBT) of the Himalayan fold‐thrust belt in northwest India is typically defined by the presence of Proterozoic rocks in the hanging wall and Cenozoic rocks in the footwall. The present study focuses on identifying the MBT contact across Gambar River section in Himachal Pradesh, India, using alternative methodologies, such as the meter‐scale litho‐structural mapping, followed by detrital zircon U–Pb geochronology to precisely identify the thrust contact and provide insights on the deformation history of the MBT zone. We have identified a sharp change in the age (from ~600 to ~61 Ma) of the sedimentary units along a narrow zone in the study area by detrital zircon U–Pb geochronology using LA‐ICP‐MS. The sharp change in the detrital zircon U–Pb age data thus delineate the MBT occurring in the area along a < ~1 m thickness. The lithological assemblage and the age data indicate the unified maximum depositional age from ~700 to ~600 Ma for the hanging wall rocks, which have been equated with the Krol Group of the Lesser Himalayan Sequence (LHS). In comparison, the footwall rocks exhibit the maximum depositional age of ~61 Ma and have been equated with the Cenozoic Subathu Formation of the Sub‐Himalayan Sequence (SHS). [ABSTRACT FROM AUTHOR]

Piemonte is widely acknowledged as a remarkable Pliocene palaeontological spot, due to its potential for the observation and study of marine and terrestrial fossils in abundant outcrops. Our observations on about 80 palaeobotanical localities, representing both terrestrial and marine sedimentary deposits, show that some of them could easily provide more significant materials than those available today. About 30 plant-bearing Pliocene sites were selected for morphological analyses on plant fossils, mainly leaf remains. The main features of each assemblage, including the systematic placement of about 400 plant samples within 52 taxa, are indexed and described in this paper, by combining analysis of palaeontological collections and field observations. The results obtained so far encourage further studies in specific areas of palaeobotanical interest, whose results could easily provide major palaeoenvironmental insights. Finally, we suggest considering more carefully the Piemonte palaeobotanical sites in the frame of geoconservation strategies and we point out the relevance of ex-situ protection of endangered plant fossil samples (collections) in order to assure their availability for future studies. [ABSTRACT FROM AUTHOR]

The northern South China Sea (SCS) margin evolved from the Mesozoic convergent to Cenozoic divergent continental margin, and thus, it developed on a heterogeneous crystalline basement with inherited Mesozoic structures. Pre-existing structures and their interactions with rift faults have historically not been described or interpreted in the intensely stretched Baiyun sub-basin. Large-scale 3D seismic reflection data allow us to identify four types of Mesozoic tectonic fabrics within the basement and explain their genesis: (1) Thin, isolated and north-dipping seismic reflections 1, interpreted as thrust faults representing orogenic processes. Tilted thick seismic reflections 2 are formed by reactivation of seismic reflections 1 during post-orogenic extension, which are all related to the NW-ward subduction of the palaeo-Pacific plate. (2) Thin, isolated and shallowly dipping seismic reflections 3 and low-amplitude, semi-transparent and chaotic seismic reflections 4 represent the low-angle thrust system and the associated nappe units, which are related to the shift from NW-to NNW-ward subduction of the paleo-Pacific plate. Subsequently, we investigate the structural interaction between Mesozoic intra-basement and Cenozoic rift structures. Syn-rift, post-rift and long-term faults are developed in Cenozoic strata, and quantitative statistical and qualitative analyses revealed two main types of structural interactions between them and underlying intra-basement structures: (1) Rift faults develop with inheritance of intra-basement structures, including fully and partially inherited faults. (2) Rift faults modify intra-basement structures, although they are controlled by intra-basement structures at an earlier stage. Finally, our results reveal the control of pre-existing structures on the geometry of the Baiyun sub-basin, especially the selective reactivation of NE-trending shear zones (SR2), which are influenced by the regional stress field and the width and dip of the shear zones. [ABSTRACT FROM AUTHOR]

Foreland basins are ideal laboratories to examine and quantify forces that contribute to Earth's topography. The interaction of these driving mechanisms (atmospheric, lithospheric and asthenospheric) affects the accumulation and preservation of strata in marine or terrestrial depocentres. For foreland basins that cover thousands of kilometres along orogens, geodynamic processes or lithospheric structure might differ and/or overlap differently along or across strike. The Magallanes-Austral basin in the southernmost Patagonia serves as a good analogue to analyse the interactions between subcrustal forces and foreland sedimentation. While to the northern part of southern Patagonia, Cenozoic basins were predominantly terrigenous and above sea level; at the southernmost end of Patagonia, sedimentation in the island of Tierra del Fuego was mostly submarine. We analysed in this contribution the southernmost foreland of Patagonia by combining backstripping with reconstruction of flexural and dynamic subsidence. These results were compared with terrestrial records exposed further north of southern Patagonia. We found that, in addition to crustal contributions (as deformation and sedimentation), subcrustal forces are required to accommodate the proximal and distal foreland strata and explain the palaeoenvironmental and subsidence discrepancies that resulted after our analysis. When our models are compared with dynamic topographic curves, strong correlations are observed during the Palaeogene, whereas strong topographic differences occurred in the Neogene. Dynamic topography models in the Neogene have reproduced clear uplift, whereas our residual topography results show equilibrium (close to the orogen) to subsidence values (to the distal foreland). We propose that changes in the lithospheric mantle had to work together with the rest of the tectonics and dynamic forces to match 1-D backstripping and flexural curves. This suggests that foreland basins in southern Patagonia were controlled differently along strike the southern Andes and that crustal deformation, asthenospheric flows and a heterogeneous lithospheric mantle structure affected the Cenozoic basin evolution. [ABSTRACT FROM AUTHOR]

The Quadrilátero Ferrífero (QF) is a globally known region for its world-class metallic deposits. Although its Precambrian units have been vastly studied since the 1960s due to economic importance, the Cenozoic geological record represents an upcoming subject of interest. The occurrence of Cenozoic sedimentary deposits has been noticed since the end of the 19th century, but most of them are not yet fully characterized. This paper brings a complete description, mapping, 3D modeling, and simulations of the sedimentary deposit named Bandeira Basin, Serra do Tamanduá, QF. Based on field data, such as mapping and drill core database analysis, three drill cores were selected for further investigation and detailed description. The Bandeira Basin can be characterized and subdivided into three units: Unit A: found only in the southeast area and shows exclusively sediments from the Nova Lima Group; Unit B: intermediate unit that occurs in central and southeast areas, with Rio das Velhas Supergroup as a possible source of the sedimentary material; and Unit C: occurs at the top, and it is essentially colluvial deposits from Minas Supergroup units. The contacts between units are abrupt or erosive, recording successive deposition stages. The basin is thicker on its central and southwest ends and thinner on the east and north, where part of the basement outcrops. Cenozoic tectonic events were probably active in this area, controlling the sedimentary processes, with the NW-SE and NE-SW lineaments reactivated, triggering sediment deposition and migration to the deepest spot of the basin. These sediments were 3D modeled in Leapfrog Geo, the visualization of any given region of interest, in the modeled scale. This methodology allowed an assertive characterization of sedimentary filling and could be applied to other basins. This comprehension is important because these sediments are used indirectly or directly in civil projects. [ABSTRACT FROM AUTHOR]

Premise of research. Polypodiaceae, the largest leptosporangiate fern family, is distributed mainly in the tropical and subtropical regions of India, China, New Zealand, and Malaysia. This family has a rich macrofossil record in the Cenozoic sediments of China, but no macrofossil of Polypodiaceae has been reported from the Cenozoic sediments of India to date. Here, we report for the first time the occurrence of fossil frond remains resembling morphologically those of the extant microsoroid wart fern genus Microsorum Link from the late Miocene Siwalik sediments exposed around Sarkaghat, Mandi district of Himachal Pradesh, Western Himalaya, India. Methodology. The present frond fossils were revealed by careful removal of the overlying matrix and studied under light compound, stereo zoom, and inverted fluorescence microscopes. They are identified based on their detailed morphological (macro and micro) features and through the comparison with other modern Polypodiaceae genera as well as with earlier reported polypodiceous fern fossil species. Pivotal results. The fossil frond specimens are described here as a new species, namely, Palaeosorum siwalikum Kundu, Hazra et Khan sp. nov. The new Siwalik vascular cryptogam species is characterized by leaf shape (simple frond with entire margin), venation pattern (brochidodromous nature of secondary veins, tertiary and quaternary veins reticulate, anastomosing and forming a row of irregular or quadrangular-shaped areoles between two lateral secondary veins), and presence of free included veinlets (unbranched or forked, ending with club-shaped hydathodes). Conclusions. These new fossil materials confirm the existence of a Microsorum -like plant in the Siwalik Miocene forests of Himachal Pradesh. We review in detail the fossil record and highlight the phytogeographic history of Polypodiaceae. In addition, we also suggest probable migratory routes for this fern family. [ABSTRACT FROM AUTHOR]

By the end of the nineteenth century, biostratigraphy had come to be thought of as a matter of induced extinctions, of varying severity, subsequent to which some surviving species would go on to generate forms adapted to the changed Earth environment. John Phillips', proposal from 1841, that the systems comprising the biostratigraphical record could be packaged into three eras—Palaeozoic, Mesozoic and Cenozoic—recognized that the end Permian and end Cretaceous were defined by extinctions that globally eliminated a large proportion of the previously abundant and long‐lived terrestrial and marine taxa. These two key horizons are now seen as defining two of a series of at least five Phanerozoic global mass extinctions, each of which suggested a short‐lived major disruption of the entire biosphere. [ABSTRACT FROM AUTHOR]

The east–west-trending South Tibetan Detachment System (STDS) and north–south-trending rifts (NSTRs) are the two main types of extensional structures that have developed within the Tibetan Plateau during continent–continent collision since the early Cenozoic. They have played significant roles in the evolution of the plateau, but it is unclear how they are related genetically. In the Yadong area of the eastern Himalaya, the NSTRs cross-cut the STDS. Apatite and zircon fission track ages of a leucogranite pluton in the footwall of the two extensional faults can be used to reconstruct the cooling and exhumation history and thereby constrain the activity of extensional structures. The new AFT ages range from 10.96 ± 0.70 to 5.68 ± 0.37 Ma, and the ZFT age is 13.57 ± 0.61 Ma. Track length distributions are unimodal, albeit negatively skewed, with standard deviations between 1.4 and 2.1 µm and mean track lengths between 11.6 and 13.4 µm. In conjunction with previously published datasets, the thermal history of the region is best explained by three distinct pulses of exhumation in the last 16 Ma. The first pulse (16–12 Ma) records a brittle slip on the STDS. The two subsequent pulses are attributed to the movement on the Yadong normal fault. The normal fault initiated at ~12 Ma and experienced a pulse of accelerated exhumation between 6.2 and 4.7 Ma, probably reflecting the occurrence of two distinct phases of fault activity within the NSTRs, which were primarily instigated by slab tear of the subducting Indian plate. [ABSTRACT FROM AUTHOR]

Egg-laying mammals (monotremes) are considered "primitive" due to traits such as oviparity, cloaca, and incomplete homeothermy, all of which they share with reptiles. Two groups of monotremes, the terrestrial echidna (Tachyglossidae) and semiaquatic platypus (Ornithorhynchidae), have evolved highly divergent characters since their emergence in the Cenozoic era. These evolutionary differences, notably including distinct electrosensory and chemosensory systems, result from adaptations to species-specific habitat conditions. To date, very few studies have examined the visual adaptation of echidna and platypus. In the present study, we show that echidna and platypus have different light absorption spectra in their dichromatic visual sensory systems at the molecular level. We analyzed absorption spectra of monotreme color opsins, long-wavelength sensitive opsin (LWS) and short-wavelength sensitive opsin 2 (SWS2). The wavelength of maximum absorbance (λmax) in LWS was 570.2 in short-beaked echidna (Tachyglossus aculeatus) and 560.6 nm in platypus (Ornithorhynchus anatinus); in SWS2, λmax was 451.7 and 442.6 nm, respectively. Thus, the spectral range in echidna color vision is ~ 10 nm longer overall than in platypus. Natural selection analysis showed that the molecular evolution of monotreme color opsins is generally functionally conserved, suggesting that these taxa rely on species-specific color vision. In order to understand the usage of color vision in monotremes, we made 24-h behavioral observations of captive echidnas at warm temperatures and analyzed the resultant ethograms. Echidnas showed cathemeral activity and various behavioral repertoires such as feeding, traveling, digging, and self-grooming without light/dark environment selectivity. Halting (careful) behavior is more frequent in dark conditions, which suggests that echidnas may be more dependent on vision during the day and olfaction at night. Color vision functions have contributed to dynamic adaptations and dramatic ecological changes during the ~ 60 million years of divergent monotreme evolution. The ethogram of various day and night behaviors in captive echidnas also contributes information relevant to habitat conservation and animal welfare in this iconic species, which is locally endangered. [ABSTRACT FROM AUTHOR]

The way in which intracontinental convergence caused by remote continent-continent collision has been accommodated remains debatable, but it is attributed to either pure shear thickening or continental subduction/ underthrusting. Quantification of the deformation architecture of the upper crust and its shortening is vital for testing these competing models. For this purpose, we conducted quantitative analyses of four seismic reflection profiles along the western Kepingtage fold-and-thrust belt of the intracontinental convergence zone between the northern Tarim Basin and the central Tian Shan, a result of the remote India-Eurasia collision, which capture the structures of the upper crust and constrain the amount of shortening in the region. The structural analyses show a thin-skinned style of deformation of the western Kepingtage fold-and-thrust belt, with minimum north--south shortening estimates of ~71.1 km (~46.6% strain), ~76.3 km (~51.4% strain), ~67.1 km (~56.1% strain), and ~53.0 km (~49.9% strain), respectively, from east to west. Assuming that coupling shortening occurred across the entire crust and an initial crustal thickness of ~41-46 km, these shortening ratios would produce a ~83-95-km-thick crust along the northern Tarim Basin, which is significantly larger than the actual thickness previously reported. This inconsistency leads us to rule out the pure-shear thickening model, which predicts crustal-scale coupling deformation. Alternatively, our results imply that the crust of the northern Tarim Basin was deformed in a decoupling style. These results, combined with those of previous studies, lend support to the intracontinental underthrusting model. We suggest that both the upper crustal fold-and-thrust belts and the lower crustal under-thrusting of the northern Tarim Basin accommodated intracontinental convergence. [ABSTRACT FROM AUTHOR]

Growth of the Tibetan Plateau, Earth's broadest and highest elevation collisional system, shapes orographic barriers, reorganizes drainage networks, and influences surface erosion and sediment delivery, whose changes in space and provenance feed back to intracontinental tectonic processes. Studies of interior basins within the northern Tibetan Plateau provide new sediment accumulation, provenance, paleodrainage, and deformation timing data that enable a reconstruction of the far-field tectono-geomorphic evolution of the rising Tibetan Plateau. Along the northern plateau margin, topographic growth in the West Qinling Belt is inferred to have initiated in the Eocene, nearly coeval with the India-Asia collision, as well as in the late Miocene. However, geological knowledge about the intervening period remains at present enigmatic, and the kinematics and dynamics are uncertain. This study presents a multidisciplinary data set from the intermontane Anhua-Huicheng Basin (AHB; Gansu Province, China) to fill this gap. Magnetostratigraphic dating, regional mapping, and sedimentological analysis imply that contractional deformation and thrust-top basin systems formed within the West Qinling Belt in the Oligocene (not later than ca. 24 Ma). A combination of observations including paleocurrent changes, detrital zircon U-Pb age variations, and appearance of growth strata along the Anhua-Huicheng Basin reveal the rapid uplift of the West Qinling Belt at ca. 15 Ma. Sedimentation in the intermontane basins ended after the late Miocene (ca. 8 Ma), when the region experienced intrabasinal deformation, uplift, and erosion with the establishment of an external drainage system. Since the late Miocene, the growth of the West Qinling Belt reached a climax with the lack of substantial contractional deformation in Cenozoic sequences heralding the onset of the modern kinematic regime and attainment of high elevation. Observed transitions in the tectonostratigraphy and paleodrainage define different phases of deformation and plateau-wide shifts in stress reorganization, which led to the northward growth and later lateral expansion of the Tibetan Plateau. [ABSTRACT FROM AUTHOR]

The tectonic mechanisms that may trigger a transition from calc-alkaline to alkaline volcanic activity above a subduction zone are enigmatic. We report major/trace elemental and Sr-Nd-Ca isotopic compositions of a suite of magmatic samples from the Miocene Gördes calc-alkaline dacites and the Quaternary Kula alkaline basalts from Western Anatolia, Turkey. Zircon sensitive high-resolution ion microprobe dating shows that the Gördes dacites formed at ca. 18 Ma. They are characterized by high-K calc-alkaline affinities, enrichment of light rare earth elements and large-ion lithophile elements (Rb, Th, U), positive Pb anomalies and negative Eu and high field strength element (HFSE) (Nb, Ta, and Ti) anomalies with high 87Sr/86Sri (0.70977-0.71010) and low εNd(t) (-7.3 to -7.0). They have small δ44/40Ca (0.59‰-0.69‰) values lower than that of mid-ocean ridge basalt (0.83% ± 0.11%). The Kula basalts exhibit alkaline affinities and are more enriched in incompatible elements (e.g., Rb, Ba, Th, Nb, Ta, Pb, and Sr) than those of typical oceanic island basalts. Their low 87Sr/86Sri (0.70307-0.70343) and high εNd(t) (+4.2 to +6.5) are consistent with an asthenospheric mantle source. Their δ44/40Ca values, ranging from 0.67‰ to 0.81‰, are higher than those of the dacites and lower than that of the bulk silicate earth (0.94‰ ± 0.10‰). Geochemical modeling suggests that variable degrees of partial melting of an asthenospheric mantle involving recycled oceanic crust may have resulted in low δ44/40Ca values of the Kula basalts. Combined with reported mantle tomographic images, we interpret that sub-slab asthenospheric mantle upwelling through a slab tear during subduction roll-back may have played a key role in the Sr-Nd-Ca isotopic variability from Miocene calc-alkaline dacites to Quaternary alkaline basalts in Western Anatolia. [ABSTRACT FROM AUTHOR]

Understanding the Cenozoic tectonic evolution of grabens rich in lignite is important in the context of the accumulation of *40-650 m of peat, as well as the exploitation of later formed lignite seams with a thickness of *20-250 m. Six such areas were selected for a detailed palaeotectonic analysis: the Gostyń, Szamotuły, Legnica, Zittau, Lubstów, and Kleszczów grabens. During the analysis, borehole data were used, taking into account the compaction of peat at the transition to lignite, in order to reconstruct the magnitude of the total subsidence. This made it possible to distinguish between regional (covering areas also outside the grabens) and local (occurring only in the grabens) tectonic movements, and among the latter, tectonic and compactional subsidence. The hypothetical palaeosurface of the mires was reconstructed based on the lignite decompaction. As a result, it was possible to determine whether the examined peat/lignite seams underwent post-depositional uplift and/or subsidence. Between one (Gostyń Graben) and four (Zittau Basin and Kleszczów Graben) stages of tectonic subsidence were distinguished in the studied lignite-bearing areas. In the case of the Zittau Basin, as well as the Lubstów and Kleszczów grabens, post-depositional stages of tectonic uplift were also indicated. Like the boundaries of lithostratigraphic units, the successive stages of the Cenozoic tectonic development of the examined grabens are diachronic. [ABSTRACT FROM AUTHOR]

The International Ocean Discovery Program (IODP) Expedition 396 to the mid-Norwegian margin recovered > 1300 m of pristinely preserved, volcanic-ash-rich sediments deposited during the late Paleocene and early Eocene from close to the centre of the North Atlantic Igneous Province (NAIP). Remarkably, many of these cores contain glendonites, pseudomorphs after the purported cold-water mineral ikaite, from sediments dated to the late Paleocene and early Eocene. These time intervals span some of the hottest climates of the Cenozoic, including the Paleocene–Eocene Thermal Maximum (PETM). Global deep-ocean temperatures are not thought to have dropped below 10 ∘ C at any point during this time, making the occurrence of supposedly cold-water (near-freezing temperature) glendonite pseudomorphs seemingly paradoxical. This study presents a detailed sedimentological, geochemical, and microscopic study of the IODP Exp. 396 glendonites and presents an updated model for the ikaite-to-calcite transformation for these glendonites. Specifically, we show that early diagenesis of basaltic ashes of the NAIP appear to have chemically promoted ikaite growth in the sediments in this region. Together with existing knowledge of late Paleocene and early Eocene glendonites from Svalbard to the north and early Eocene glendonites from Denmark to the south, these new glendonite finds possibly imply episodic, short-duration, and likely localized cooling in the Nordic Seas region, which may have been directly or indirectly linked to the emplacement of the NAIP. [ABSTRACT FROM AUTHOR]

Titanite is a widespread accessory mineral in igneous, metamorphic, and hydrothermal rocks, but few comply with gem-grade requirements. Previous studies on Moroccan titanite focused on elementary composition and U-Pb dating. In this study, two gem-grade titanites (MA-1 and MA-2) from the Moroccan Central High Atlas were investigated through gemological and chemical studies, including infrared spectrum, Raman spectrum, SEM-EDS, and LA-ICP-MS. Two titanite samples are yellow, transparent–translucent with a greasy luster, 3.5 and 2.5 mm long. MA-1 and MA-2 have similar gemological properties, the refractive index (RI) is beyond the range of the refractometer (>1.78), the specific gravity (SG) values fall in the range of 3.52~3.54 and both are inert to short-wave and long-wave UV radiation. The spectral characteristics have high consistency with the RRUFF database. The major elements' composition shows a negative correlation between Al, Fe, V, and Ti, suggesting the titanites underwent substitutions such as (Al, Fe3+) + (F, OH) ↔ Ti + O. The titanite samples, characterized by a low abundance of REE (802~4088 ppm) and enriched in LREE, exhibit positive Eu (δEu: 1.53~7.79) and Ce (δCe: 1.08~1.33) anomalies, indicating their formation in a hydrothermal environment with low oxygen fugacity. The 238U/206Pb and 207Pb/206Pb ratios of the titanites yield lower intercept ages of 152.6 ± 2.2 and 151.4 ± 5.3 Ma (1s), consistent with their weighted average 206Pb/238U ages of 152.3 ± 2.0 and 150.7 ± 3.2 Ma (1s) respectively. The results of U-Pb dating are matched with the second main magmatic activities in the High Atlas intracontinental belt of Morocco during the Mesozoic to Cenozoic period. Moreover, the two titanite samples have almost no radiational damage. All the results show that the titanite from High Atlas, Morocco, has the potential to be a reference material for LA-ICP-MS U–Pb dating, but further experiments are needed to be sure. [ABSTRACT FROM AUTHOR]

Modern views on the origin and early evolution of mammals are presented. The material accumulated by the author on the morphology of modern and fossil monotremes, marsupials, and placentals are used. Data on Mesozoic mammals, including those obtained in recent years, are summarized. A model of the mechanism of morphogenetic transformations during the evolutionary development of Mammalia is proposed. An overview of the main directions of the formation of mammals from the Late Triassic to the Cenozoic is given. [ABSTRACT FROM AUTHOR]

Insect faunas from the latest Cretaceous are poorly known worldwide. Particularly, in the Southern Hemisphere, there is a gap regarding insect assemblages in the Campanian-Maastrichtian interval. Here we present an insect assemblage from the Maastrichtian Chorrillo Formation, southern Argentina, represented by well-preserved and non-deformed, chitinous microscopic remains including head capsules, wings and scales. Identified clades include Chironomidae dipterans, Coelolepida lepidopterans, and Ephemeroptera. The assemblage taxonomically resembles those of Cenozoic age, rather than other Mesozoic assemblages, in being composed by diverse chironomids and lepidopterans. To the best of our knowledge, present discovery constitutes the first insect body fossils for the Maastrichtian in the Southern Hemisphere, thus filling the gap between well-known Early Cretaceous entomofaunas and those of Paleogene age. The presented evidence shows that modern clades of chironomids were already dominant and diversified by the end of the Cretaceous, in concert with the parallel radiation of aquatic angiosperms which became dominant in freshwater habitats. This exceptional finding encourages the active search of microscopic remains of fossil arthropods in other geological units, which could provide a unique way of enhancing our knowledge on the past diversity of the clade. An insect assemblage gathered from the Chorrillo Formation in Argentina constitutes an important set of insect body fossils for the Maastrichtian interval in the Southern Hemisphere. [ABSTRACT FROM AUTHOR]

Trapa L. (Lythraceae J. ST.-HIL) is a genus of annual free-floating plant, widely distributed in the Northern Hemisphere. The Qaidam Basin is regarded as an ideal region to understand the Cenozoic palaeoclimatic and palaeobiological evolution of the northern Tibetan Plateau. A few records of Trapa have been previously mentioned from the Cenozoic deposits of the Qaidam Basin, northern Tibetan Plateau. Here, we describe some fossil fruits of Trapa from the late Miocene Shangyoushashan Formation of southeastern Qaidam Basin (Tuosu Lake area), which were identified as Trapa qaidamensis sp. nov. based on their morphology. Extant species of Trapa usually live in the environments with mean temperature of warmest quarter (MTWQ) ranging from 14.9°C to 30.9°C, as well as mean temperature of warmest month (MTWM) ranging from 19.6°C to 37.3°C in the living areas of Trapa. Compared with MTWQ 16.5°C and MTWM 17.5°C in current fossil locality, the present fossil site was warmer during the Miocene than in the present day [ABSTRACT FROM AUTHOR]

The Eocene compressional phase is well known to have contributed to the construction of the Andes orogen at latitudes north of 30° S, but its extension to the south has not been fully studied. Moreover, synorogenic deposits of Eocene age across the foreland are scarce. The Cenozoic Manantiales Basin records the unroofing sequence of the Andes at 32° S. This study focuses on the basal infill of the Manantiales Basin, informally called the Areniscas Chocolate, which has received less attention than the upper infill until now. Sedimentological, geochronological and provenance studies were carried out on this unit. Here, we present the first ages for the Areniscas Chocolate sequence, of ca. 35–39 Ma (maximum depositional age, MDA). This MDA is interpreted as close to its depositional age, which together with their stratigraphic characteristics, allow us both to separate it from the overlying Miocene Chinches Formation and to propose it as an independent lithostratigraphic unit called Río de los Patos Formation (nov. den.). The provenance analysis of the Río delos Patos Formation indicates a sediment input from western sources located in the Coastal Cordillera and Western Principal Cordillera. Facies associations suggest that the Río de los Patos Formation represents the distal synorogenic deposits during the construction of an Eocene relief to the west. Therefore, the Manantiales Basin started during the late Eocene as a distal foreland basin, indicating that Eocene compression reached latitudes as far south as 32° S. Our results shed light into the characterization of the earliest infill of the Manantiales Basin, as well as into the tectonic evolution of the basin. [ABSTRACT FROM AUTHOR]

The Khangai plume is situated under Central and Eastern Mongolia and is a mantle volume with significantly reduced longitudinal (P) wave velocities. The plume has been identified as a result of the analysis of the MITP08 volumetric model of P-wave velocity variations, representing the deviations of P-wave velocities from the average values (δVp), given as a percentage. The lithospheric mantle is thinned to ca. 50 km above the plume. Especially low velocities (δVp ≤ –0.6%) are found in the sublithospheric mantle up to a depth of 400 km. The main body of the plume is located under the Khangai Highland and extends northward to the edge of Southern Siberia. The Khentei branch of the plume that is located SE of the Khentei Highland is connected with the main plume body at depths of 800–1000 km. Branches of the plume and its Khentei branch extend into Transbaikalia. The area of the plume decreases with depth, and its deepest part (1250–1300 km) is located under the southern Khangai Highland. The main body of the Khangai plume is expressed on the land surface by the Cenozoic uplift reaching 3500–4000 m in the southern Khangai Highland. From the SE, the Khangai plume and its Khentei branch territory are limited by Late Cenozoic troughs stretching along the southeastern border of Mongolia. From other sides, the Khangai uplift is bounded by a C-shaped belt of basins. The belt includes the southwestern part of the Baikal Rift Zone, the Tunka and Tuva Basins in the north, the Ubsu-Nur Basin and the Basin of Big Lakes in the west, and the Valley of Lakes in the south. The basins are filled with lacustrine and fluvial deposits of the Late Oligocene to Pliocene. In the Quaternary, the South and Central Baikal Basins, which existed as early as the Early Paleogene, became a part of the Baikal Rift, and the other basins were involved in the general uplift of the region. The structural paragenesis of the Khangai uplift and the surrounding basins is caused by the influence of the Khangai plume. On the territory above the plume, including its Khentei and Transbaikalia branches, the Cenozoic basaltic plume volcanism occurred, inheriting the Cretaceous volcanic manifestations in some places. The structural paragenesis associated with the Khangai plume is combined with the structural paragenesis produced by lithospheric plate interaction. The latter is expressed the best of all by active faults, but developed synchronously to the plume paragenesis. The active fault kinematics shows that the eastern and central parts of the region developed in the transpression conditions and the north-eastern part developed in conditions of extension and transtension. The Khangai plume is connected at depth with the Tibetan plume, which is situated under the central and eastern Tibetan Plateau north of the Lhasa block. The Tibetan plume has the shape of a funnel rising from depths of 1400–1600 km and is accompanied by thinning of the lithosphere and uplift of the land surface. The Khangai and Tibetan plumes represent a specific category of plumes. They rise from the upper Lower Mantle and differ by this from the Upper Mantle plumes and the African and Pacific superplumes rising from the core-mantle boundary. Data are presented on the possible connection of the Khangai and Tibetan plumes with the superplume branches, but independent origin of the plumes is also admitted. [ABSTRACT FROM AUTHOR]

Based on the results of field complex geophysical studies in the northwestern part of the Russian sector of the Barents Sea shelf, as well as on the processing and comprehensive interpretation of new and retrospective geophysical materials in the volume of 25 500 linear kilometers and deep well drilling data in the section of the Barents Sea sedimentary cover, regional tectonostratigraphic units were identified between reflecting horizons (RH): (i) a Paleozoic complex (between RH VI(PR?) and RH I2(P‒T)); (ii) a Triassic complex (between RH I2(P‒T) and RH B(T‒J)); (iii) a Jurassic complex (between RH B(T‒J) and RH C′(J3‒K1)); and (iv) a Cretaceous‒Cenozoic complex (between RH V′(J3‒K1) and the Barents Sea floor). According to the structural analysis results, three structural floors were established: the lower structural level, which includes Riphean terrigenous-effusive deposits and Lower Paleozoic‒Lower Permian terrigenous-carbonate deposits; the middle structural level is formed mainly by Upper Devonian‒Lower Permian carbonate deposits; the upper structural level combines Lower and Upper Permian terrigenous deposits and Mesozoic–Cenozoic deposits. This article presents a new tectonic model of the Barents Sea region, including elements of all structural levels with sublevels. In accordance with the tectonic zoning, paleostructural and paleotectonic analyses, the article outlines the main stages of the Barents Sea shelf development: stage of the Late Proterozoic compression and Early–Middle Paleozoic continental rifting (I), a Late Paleozoic stabilization stage (II), an Early Mesozoic tectonogenesis stage (III), a Middle Mesozoic thermal subsidence stage (IV), a Late Jurassic stabilization stage (V), a Cretaceous subsidence stage (VI), and the final stage as a Cenozoic uplift of a large part of the Barents Sea shelf (VII). In the northwestern part of the Russian sector of the Barents Sea shelf, synchronous subsidence of the sedimentary cover basement took place, associated with spreading and formation of the Arctic Ocean. [ABSTRACT FROM AUTHOR]

Fossil pearls are rare but important palaeoecological indicators in proving the former presence of parasites. A single right valve of Hyotissa hyotis from the Pliocene of Sidi Brahim shows numerous blister pearls inside the adductor muscle imprint. At the same locality, numerous shells with smooth adductor scars and without any blisters, have been collected. The structures in the studied valve can be assigned to blister pearls with high confidence due to their similarity to other Cenozoic pearls from Austria. The blister pearls likely formed as a reaction to parasite infestation. It is possible that some parasites especially targeted areas associated with the adductor muscles in the oyster genus Hyotissa, because similar blister pearls have previously been described in a congeneric species, H. squarrosa, from the Miocene of Austria. [ABSTRACT FROM AUTHOR]

Since the Late Cenozoic, tectonic deformation has been intense in the Longxian–Baoji Fault Zone (LBFZ), which is at the intersection of the southwest margin of the Ordos Block, the northeast margin of the Tibet Plateau, and the Qinling Orogenic Belt. To evaluate the relative tectonic activity within the LBFZ and discuss the influence of the northeastward expansion of the Tibetan Plateau on the geomorphological evolution of the LBFZ, we extracted data of the Qianhe, Hengshuihe, and Jinlinghe River Basins from the ASTER GDEM and analyzed the geomorphic indices, including the hypsometric integral (HI), standardized stream length-gradient index (SL/K) and Hack profile, elongation ratio (Re), the drainage basin asymmetry factor (AF) and valley floor width-to-height ratio (VF). Through geomorphic indices and field investigations, we found that the LBFZ has experienced relatively high tectonic activity. Combined with the index of relative active tectonics (IAT), we compared the tectonic activity strengths of the four major faults in the study area. Among them, the tectonic activities of the Longxian-Qishan Fault (LQF) and the Taoyuan-Guichuansi Fault (TGF) are the highest. The morphology and AF values of the drainage basin of the southwest side of the study area indicate the influence of northwest-southeast compressive stress. The northeastward expansion of the Tibetan Plateau affected the LBFZ region, and the stress brought about by it controlled the tectonic deformation in the region and sculpted the modern landscape. This study is of great significance for understanding the impact of the northeastward expansion of the Tibetan Plateau on the geomorphological evolution of the LBFZ. [ABSTRACT FROM AUTHOR]

The Late Pliocene Gilbert-type delta is described in the western Erzurum Basin (NE Turkiye) and its position in the Late Cenozoic development of the basin is defined. The Erzurum Basin originated no later than Late Miocene between two Mesozoic ophiolite zones, continuing the Izmir–Ankara–Erzincan suture. In the Late Miocene–Pliocene, the basin was filled with fine-grained clastic and carbonate sediments of lacustrine-lagoon type. The Gilbert-type delta formed at the top of these deposits in the western part of the basin. The delta consists of 11 wedge-shaped bodies of clay, silt, sand, and gravel that were deposited as foresets of different phases of the delta development. The foreset bodies are dipping at 5° to 35° E. Some bodies underwent soft sediment deformation. The delta deposits are dated to Late Pliocene based on remains of small mammals and molluscs, palynological, and magneto-stratigraphic analysis. The delta eroded surface is overlain by alluvial pebbles dated to Early Pleistocene by archaeological finds. The Erzurum Basin is the westernmost member in a row of intermontane basins that continues to the east with the Pasinler, Horasan, and Agri basins that are drained by the Araxes River and its tributaries. It is likely that the paleo-Araxes River spread to the west in Late Pliocene and the studied delta was formed by its upper reaches that flowed into the water body of the Erzurum Basin. The delta deposits were covered by coarse alluvium in Early Pleistocene when the Erzurum Basin was tectonically isolated from the Araxes drainage system. In the latest Early Pleistocene or early Middle Pleistocene, the paleo-Araxes upper reaches were captured by the Euphrates River upper reaches that drain the Erzurum Basin now. The Upper Miocene and Pliocene deposits of the Erzurum, Pasinler, and Horasan Basins are similar and were accumulated in a single basin of sedimentation. Therefore, it can be assumed that the deposits of the upper Pliocene, containing the Akchagylian marine biota in the Horasan Basin, extended into the Erzurum Basin. However, the assumption that the upper reaches of the Euphrates River and the Erzurum Basin were the channel, through which the open sea biota entered the Akchagylian basin, is very unlikely for two reasons. Firstly, the Erzurum basin was limited by the described delta of the river, which flowed into it from the west. Secondly, the upper reaches of the Euphrates penetrated into the Erzurum Basin after the completion of the Akchagylian stage of sedimentation. [ABSTRACT FROM AUTHOR]

The results of a comprehensive study of the Upper Cenozoic Ulan-Zhalga reference section in western Transbaikalia are presented. The paleontological, paleomagnetic and petromagnetic, lithological-mineralogical, and geochemical data obtained allowed us to identify and characterize the Lower, Middle, and Upper Pleistocene and Holocene deposits in the section and to reveal the features and conditions of sedimentation. Five members recognized in the section are combined into two sequences: the lower (Beds 1–27, units 1–3) and the upper (Beds 28–35, units 4–5). The boundary between Matuyama and Brunhes chrons (0.773 Ma) is determined at a depth of 15 m and the upper boundary of the Jaramillo subchron (0.990 Ma) is determined at a depth of 23 m. The Matuyama/Brunhes boundary coincides with the boundary of Lower and Middle Pleistocene faunal assemblages. The formation of the section corresponds to two major stages of sedimentation with the boundary between the units 3 and 4 (depth of 11.8 m). Changes in rock magnetic and grain size parameters through the section has a climatic nature and reflects environmental changes. The formation of the lower part of the section (unit 1), which was accompanied by active soil formation, is characterized by the most heat- and moisture-enriched conditions. The upper sequence of the section accumulated under colder and drier conditions with increased dynamics of aeolian processes. [ABSTRACT FROM AUTHOR]

The Zaisan Depression is a unique geological structure that preserves the most complete sedimentary record of the Late Mesozoic and most of the Cenozoic. A century of studies brought very rich data on the stratigraphy and geological history of the Zaisan sedimentary sequence. The recent scientific progress made it possible to refine the Cenozoic stratigraphic scale of the region. This paper presents the results of a detailed morphostructural analysis and proposes morphotectonic zoning of the Zaisan Depression based on the modern tectonic and geodynamic concepts. New data on magnetostratigraphic subdivision of the Kalmakpai stratotype section, the most complete section of the sedimentary strata of the Zaisan Depression, and on its correlation with the drilling data of its axial part are presented. By the synthesis of magnetostratigraphy with the rich regional biostratigraphic record, the stratigraphy of the region, the dynamics of tectonic movements, and the development of topography and landscapes of the Zaisan Depression and the framing high-mountain structures of Saur-Tarbagatai during the Cenozoic are clarified. [ABSTRACT FROM AUTHOR]

Paleostress reconstruction through polyphase fault-slip data of a multi-deformed region suffered collisional tectonics can lead to detecting the stress phases. Based on earthquakes' focal mechanisms and morphotectonic features, multiple deformation phases model has been proposed for the Alborz Mountains located in the collision zone between the Arabian (Central Iran) and Eurasian (South Caspian block) plates during the Late Cenozoic. In this study, paleostress analysis has been carried out in an area bounded by two (Kandovan and Taleghan) regional faults in the Central Alborz Mountains using fault-slip data. This analysis resulted in the identification of three main tectonic phases. The first, compressional phase is proposed to cause the inversion of the Alborz Mountains' major initial normal faults to reverse faults during the convergence of the Arabian and Eurasian plates. The second, transpressional phase is offered as a factor for the reactivation of the hidden Alborz basement faults to form the NE-striking left-lateral strike-slip faults on the sedimentary cover. The third, transtensional phase is suggested to be responsible for the development of the NNE-SSW left-lateral transtensional faults. It is proposed that the second and third paleostress phases are affected mainly by the indentation of the South Caspian Block into the Alborz Mountains during the Late Cenozoic. [ABSTRACT FROM AUTHOR]

The paper presents original and published geochronological data on the volcanic rocks of the Magellan Seamounts. These data and available geological materials allow us to distinguish five major volcanic complexes of different ages in the guyots of the Magellan Seamounts: (1) Late Jurassic–Early Cretaceous (earliest Cretaceous); (2) Early Cretaceous (Aptian–Albian); (3) Late Cretaceous (Late Cenomanian–Turonian–Early Campanian); (4) Late Cretaceous (Late Campanian–Maastrichtian); (5) Cenozoic. Each of these age complexes corresponds to a peculiar tectonomagmatic stage of the evolution of the Magellan Seamounts and characterizes a specific geomorphological space (pedestal, main body, small complicating superimposed structures of the second order). This division is based on the numerous isotopic age determinations for 11 guyots obtained by K-Ar and Ar-Ar methods. The tectonomagmatic evolutionary stages of the Magellan Seamounts correspond, in general, to the periods of tectonic activation for other structures of the Pacific seafloor. [ABSTRACT FROM AUTHOR]