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Detailed field and stratigraphic (lithostratigraphy & biostratigraphy) studies were carried out on the Upper Cretaceous–lower Paleogene successions at Esh-ElMellaha half-graben, Gulf of Suez, Egypt. Four stratigraphic sections were investigated and arranged in a geologic profile extends from south to north as follow: Gabal El-Mellaha, Wadi Abu Had, Wadi Dib and Gabal Tarbul. The field work led to recognize four lithostratigraphic units (formations): Sudr (upper part), Dib, Esna and Thebes (top). The distinctive Dababiya Quarry Member (DQM) which characterizes the Paleocene Eocene Thermal Maximum (PETM) was initially recorded at Esh-ElMellaha region. Sudr Formation is stratigraphically differentiated into two distinctive informal rock units, argillaceous bedded limestone unit and calcareous shale unit. The Dib Formation is here reviewed and correlates with the Dakhla Formation (upper part) in the different geographic neighborhoods of Egypt. It consists of glauconitic carbonate rocks (bioclastic limestone) embracing reworked gravelly and pebbly extra-clasts and broken exhumed mega-fossils (e.g. cephalopods, gastropods and bivalves, corals). Dib Formation is assigned to thelower Paleocene (Danian Stage) according to the occurrence of praemuricids taxa (e.g. Praemurica inconstans and P. uncinata) index fossils. Esna and Thebes formations are assigned to the Ypresian Stage. Dib Formation is bounded by two regional unconformity surfaces (erosional surfaces) as a result of two tectonic events (I and II) linked to Syrian Tectonic Event. • New insights into Esh-ElMellaha stratigraphy were achieved. • Reference section of the Dib Formation was introduced for the first time. • El-Dababiya Quarry Member, which marks the PETM, was defined. • Unconformity surfaces (Paleosol and irregular surfaces) were observed. • Two major syn-sedimentary tectonic events (K/Pg & P/E) were documented. [ABSTRACT FROM AUTHOR]

Investigating the fossil record to provide evidence about the response of shallow-water tropical calcifiers to past warming events is crucial considering that they are severely threatened by current global warming. We thus focused our attention on scleractinian reef corals (SRC) and shallow-water foraminifera (SWF), both mainly symbiont-bearing organisms, analysing and comparing their diversity patterns during the Paleocene and Eocene from datasets of the Neothetyan circum-Mediterranean region. In particular, at both genus and species level, we analysed changes in diversity, together with origination and extinction rates. Despite some biases related to biostratigraphic resolution of SRC and SWF data, our results show that they reacted differently to the major warming events of the Early Paleogene. The K/Pg mass extinction caused the disappearance of almost all SWF, whereas several corals passed this crisis and persisted up to the end of Paleocene, when the Paleocene-Eocene Thermal Maximum (PETM) caused a relatively small decrease of coral diversity together with a global collapse of coral reefs. On the other hand, a rapid radiation of nummulitids and alveolinids occurred at species level. The impact of the Early Eocene Climatic Optimum (EECO) was apparently more severe for SWF than for SRC. After the Middle Eocene Climatic Optimum (MECO), the general cooling trend led to the fading of Eocene SWF genera and species, whereas SRC began their rapid diversification from Bartonian to Priabonian and culminating in the Chattian. Our results suggest that rapid warming events favoured speciation in SWF, whereas the slow cooling trend (e.g., after the MECO) favoured diversification of SRC. Our data also underline that SWF reacted differently to warming events as compared to deep-sea smaller benthic foraminifera and that the same events in the planktonic realm are not strictly coeval with those occurring in shallow-water environments. On a wider perspective, we observe that shallow-water calcifiers demonstrate a good degree of resilience to global temperature increases, even if undergoing to more or less marked reduction of biodiversity. We provide evidences for the recovery of past ecosystems from both short and long stressors. • Paleocene-Eocene foraminifera and corals biodiversity is affected by warming events. • The response of foraminifera and corals to the same warming events is different. • Foraminiferal diversity is more susceptible to rapid warming events. • Coral diversity appears less influenced by warming events. • Generally, both groups exhibit quite high resilience to warming events. [ABSTRACT FROM AUTHOR]

Forty-six species of radiolarians recovered from the Upper Cretaceous Smoking Hills and Mason River formations in the Northwest Territories represent the first assemblage of this age from mainland Arctic Canada. Four interval zones and two subzones, calibrated to radiometric ages, are proposed based on the lowest and highest occurrence of index radiolarian species. These are 1) the Santonian/early Campanian Kuppelella aff. cayeuxi Zone, 2) the middle Campanian Diacanthocapsa aff. rotunda Zone (subdivided into the Kreuzstella vierkantiga and Lithostrobus borealis subzones), 3) the late Campanian Canadasphaera inuita Zone, and 4) the early Maastrichtian Stichomitra cf. communis-Xitus sp. B Zone. Integration of these radiolarian biozones with previously reported diatom, silicoflagellate, palynological and foraminiferal biozones and new radiometric ages indicate a middle Coniacian-middle Campanian age for the Smoking Hills Formation and a middle Campanian-late Maastrichtian (probably Paleocene) age for the Mason River Formation. The radiolarian assemblages reported here resemble those of the North Slope of Alaska and western Siberia, allowing for biostratigraphic correlations within the Arctic Realm. • Highly diverse Cretaceous radiolarian assemblage recovered from the Canadian Arctic. • Four radiolarian biozones identified, spanning Santonian to lower Maastrichtian. • Age refined using correlation with siliceous microfossils and radiometric dating. • Potential for an Upper Cretaceous radiolarian biozonation in the Arctic Realm. [ABSTRACT FROM AUTHOR]

[Display omitted] • We explained the tectonic evolution of the Eastern Subbasin since the Late Cretaceous that marks the eastern margin of the Northern South Yellow Sea Basin. • The evolution of the subbasin includes not only subsidence (rapid, slow, accelerated, and gradual) but short-term uplift. • The subbasin evolved with sequential development of nested duplex structures created by dextral extension. • The NW subduction of the Pacific Plate oblique to the NE Asian margin played an important role by inducing SE extension at the margin and NE-SW transtensional dextral slip parallel to the margin. The South Yellow Sea Basin is the largest sedimentary basin in the Yellow Sea. The Gunsan Basin in the central eastern part of the Northern South Yellow Sea Basin comprises the Western, Central, and Eastern Subbasins. The Eastern Subbasin marks the eastern margin of the South Yellow Sea Basin. Interpretation of multi-channel seismic profiles and balanced cross-section restoration of depth-converted seismic profiles reveal the structural characteristics and evolution of the Eastern Subbasin. The subbasin comprises three groups of faults: NW-SE, NE-SW, and NNE-SSW trending faults. The subsidence pattern of the subbasin, derived from the cross-section restoration analysis, indicates five distinguished evolution phases: (i) rapid subsidence in the Late Cretaceous, (ii) slow subsidence from the Paleocene to the Eocene, (iii) accelerated subsidence in the Oligocene, (iv) alternation of the uplift and subsidence in the Early Miocene, and (v) gradual subsidence since the Middle Miocene. The main and moderate subsidence can be explained by the combination of extension in the SE and NE-SW directions that formed double duplex structures. We suggest that the NW oblique subduction of the Pacific Plate under the NE Asia margin induced both extension toward the trench and dextral strike-slip parallel to the margin. The extension toward the trench caused SE transtension in a local pull-apart setting, whereas the dextral strike-slip parallel to the margin caused NE-SW extension, inducing more significant subsidence. The combined processes resulted in the progressive development of nested duplex structures. The evolution of the Eastern Subbasin is not compatible with previously suggested models for the western part of the South Yellow Sea Basin including foreland basin formation and transtension induced by branch faults of the Tan-Lu Fault. [ABSTRACT FROM AUTHOR]

Little is known about the Paleocene in the southern Pacific Ocean due to scarce marine records. Here, we present a systematic geochemical investigation using biomarkers, carbonate content, and carbon isotopes of a set of early Paleocene deep-sea cores from International Ocean Discovery Program Expedition 378 Site U1553. The results provide a new Paleocene biomarker profile for the Campbell Plateau, New Zealand. The occurrence and distribution of a series of hopenes, ββ hopanes, sterenes and biomarker-based maturity parameters indicate that these organically-lean sediments are in an early diagenetic stage, with an equivalent vitrinite reflectance of approximately 0.4%. Biomarker data (e.g., gammacerane index and homohopane index), carbonate carbon isotopes (−27.9 ‰ to +2.0 ‰) combined with onboard data (sulphur and methane contents) indicate that the redox properties of the Paleocene southern Pacific Ocean changed from an oxidising-anoxic transition zone to a more reducing marine environment (water depth > 1000 m). The sources of the organic matter are diverse, including algae, bacteria, diatoms, dinoflagellates, and higher plants, but are dominated by aquatic organisms. Our new biomarker record bridges a Paleocene biosphere knowledge gap in the high latitude South Pacific. • First biomarker profile from Paleocene southern Pacific Ocean is established. • Depositional model indicates an oxidising-anoxic marine slope environment with aquatic organisms-dominated organic matter source. • These organically-lean sediments have an equivalent vitrinite reflectance of 0.4%. [ABSTRACT FROM AUTHOR]

The advent of the Paleocene-Eocene Thermal Maximum (PETM), a ∼ 200 kyr period of global warming ca. 56 Ma, caused sea-levels to rise, transgressing near-coastal environments in southeastern (SE) Australia over >55,000 km2. During the PETM, warming tropical climates may have extended south to ≥60°S paleolatitude. The PETM in SE Australia is corroborated primarily by stable carbon isotope chemostratigraphy and detailed palynology records in four geological basins. Previous work showed that, in addition to the globally recognised carbon isotope excursion, the PETM interval in coastal SE Australia can be identified using the dual occurrence of the tropical mangrove Nypa palm pollen (Spinizonocolpites prominatus) accompanied by thermophilic marine dinoflagellate cysts (mainly Apectodinium hyperacanthum). We here document a total of twenty-six Gippsland Basin wells that record this Nypa - A.hyperacanthum association in the earliest Eocene Kingfish Formation (Lower Malvacipollis diversus Zone). In the Bass Basin, eight wells record Nypa-A.hyperacanthum association within the Eastern View Group basal Koorkah Formation, or lower part of the Lower M. diversus Zone (earliest Eocene). In the Bass Basin a further thirteen wells with Nypa occurrences near the top of the Cormorant Formation are found, which might be associated with the longer-term warmth of the Early Eocene Climatic Optimum (EECO, ∼53–49 Ma). Government bores and petroleum wells across the Otway Basin record the Nypa-A. hyperacanthum PETM association within the Pember Mudstone Lower M. diversus Zone in twenty-one bores. Nine horizons with Nypa occurrences occur within the Burrungule Member (EECO) at the top of the Dilwyn Formation. In western Tasmania, Nypa occurs in the Sorell Basin and Macquarie Harbour area within the Lower M. diversus Zone. Together, these observations show the remarkable extent of the mangrove-coasts that were established across the mid-high paleolatitudes in SE Australia during the warmest intervals of the Cenozoic, the PETM and EECO. • In 56 Ma SE Australia, 5 m sealevels flooded >55,000km2 of near-coastal environments. • PETM megathermal biota are found at localities down to ∼65°S paleolatitude. • The PETM is identified in the Gippsland, Bass, Otway and Sorell basins. • The PETM contains mangrove Nypa palm pollen (Spinizonocolpites prominatus). • Thermophylic marine dinoflagellates include Apectodinium hyperacanthum. [ABSTRACT FROM AUTHOR]

It has long been debated whether the India-Eurasia collision was a single-stage event that began 60-55 million years ago, or whether it was a two-stage process that involved a collision between India and the Trans-Tethyan Arc before the early Paleocene, and the collision of India with Eurasia during the middle Eocene. Here, we report a late Paleogene angular unconformity (ca. 40-28 Ma) in western Myanmar. This angular unconformity developed around the same time as the Assam unconformity (NE India) but is younger than those found in northern Myanmar. Development of these unconformities indicates that an oblique convergence margin in western Myanmar formed before the middle Eocene, with a major dextral strike-slip fault (proto-Sagaing/Shan Scarp Fault) in the backarc. We interpret this oblique convergence margin to be partial continental collision between the West Myanmar Terrane (WMT) and NE India. In backarc regions, syn-rift successions of the Shwebo sub-basin have formed as a consequence of transtensional tectonics along the proto-Sagaing/Shan Scarp Fault since at least the late Paleocene. The syn-rift successions consist of Asian-derived materials that were not identified in the forearc because of the Wuntho-Popa Arc served as a geographical barrier. The presence of the unconformities and tectonic configuration of the Myanmar backarc sub-basins are inconsistent with the scenario inferred from paleomagnetic data, in which the WMT was part of an intra-oceanic arc at near-equatorial latitudes before the late Oligocene. Instead, we propose that the WMT has been part of continental SE Asia since at least the Paleocene (ca. 60-58 Ma). We reconsider the paleomagnetic data and suggest that the Mawgyi Arc, rather than the WMT, is the oceanic fragment that rifted from the northern Gondwana margin during the Late Jurassic. The Mawgyi Arc collided with continental SE Asia (WMT) during the Late Cretaceous, and then with India during the early Eocene (ca. 51-49 Ma). Our results support the collision between India and Eurasia is a multistage event. • Our findings support a two-stage India-Asia collision scenario. • The unconformities propagated from north to south over western Myanmar during the Paleogene. • Syn-Rift sequences of the Shwebo basin were produced by transtensional faulting. • The West Myanmar Terrane was anchored on SE Asia before the late Paleocene (60-58 Ma). [ABSTRACT FROM AUTHOR]

An integrated approach combining petrography, photogrammetry, geochronology, SEM, and geochemical data was utilized to analyze lithofacies, stacking patterns, and lateral facies variations, and to interpret environmental dynamics during the deposition of carbonates from 'La Barre du Cengle' in the Early Paleogene. Located in the SE of France, the elliptical Cengle Plateau stretches 7 km from east to west and is 2 km wide, featuring cliffs ranging in thickness from 20 to 35 m. These cliffs showcase grayish, beige, and pinkish limestones dominated by palustrine facies, forming part of the 'Calcaire de Saint Marc' Formation of the Arc Basin. Sedimentary deposits within this interval were repeatedly subjected to subaerial exposure due to fluctuations in lake levels driven by climate, resulting in the organization of elementary sequences at decimetric to metric scales, which stack up into small-scale sequences at the decametric order. Deposition occurred under mainly subarid climatic conditions, with paleogeographic variations in the basin corresponding to changes in lake base levels over time and space. At least four frequencies of base level variation are present: very high and seasonal frequency, responsible for the formation of palustrine facies; high frequency, which generates the elementary sequences; medium frequency, which leads to the formation of the small-scale sequences; and low frequency which corresponds to the deposition of the entire set of limestones that form the Cengle cliff. The transition between lacustrine, palustrine, and pedogenic environments consistently occurs from west to east over time. In the more distal regions, the proportion of lacustrine facies tends to increase, and the thicknesses of the preserved sedimentary record tend to be greater. Conversely, palustrine and pedogenic facies predominate in the more proximal areas, typically resulting in decreased thickness. • Lithofacies anatomy reveals environmental dynamics in limestone deposition. • Vertical stacking pattern and lateral variation in lacustrine–palustrine sequences • Cyclical deposition patterns linked to climate-driven lake level fluctuations • Development of an exposure index as an indicator for subaerial exposure duration • Proposal of a model predicting facies & thickness in palustrine-dominated sequences [ABSTRACT FROM AUTHOR]

The structural analysis of the Bizerte area in northern Tunisia, utilizing well data and field observations, reveals a complex arrangement of fold structures characterized by recumbent fold nappes to local sheath-like fold structures, indicative of a deep detachment phenomenon. The genesis and present geometry of these fold structures unravel a multifaceted structural history: (i) In the Tortonian folding phase, a detachment mechanism may have initiated the formation of a horizontal shearing plane at the base of the Paleocene marls. The gradual evolution of syn-shear recumbent fold nappes into sheath folds within sedimentary to pseudo-metamorphic rocks is attributed to a flow perturbation process analogue to "layer-parallel shearing," dictating the geometric configuration of folds subsequent to a simple shear inducing perturbations in pre-existing layer disturbances. (ii) During the Late Quaternary shortening phase, a NW-trending right lateral shear zone emerged, delineated by the reactivation of pre-existing faults under compression. The reorientation of the anterior fold axes is attributed to the counterclockwise rotation of rigid blocks within the framework of P-type conjugate fractures. (iii) The transition to thin-skinned tectonics, characterized by the uplift of previously buried material, was characterized by a significant increase in shortening during Neogene events, encompassed in the broader regional geodynamic context of continental collision. From the Lower Quaternary onward, the structural model exhibits a combination of layer-parallel and layer-normal shear processes. • Recumbent fold nappes in the Bizerte area are generated through a detachment mechanism within the El Haria (Paleocene) incompetent marls. • The detachment process is initiated following compressive deformations, leading to high shear strain and subsequent flow processes perturbation. • Due to sustained shortening during the Neogene Period, the tectonic style underwent transition to thin-skinned tectonics and counterclockwise rotation of rigid blocks along P-shears. [ABSTRACT FROM AUTHOR]

The "septarian barite concretions" have garnered significant interest worldwide. This study presents the first detailed investigation of these sedimentary structures in Algeria, with a primary focus on elucidating their genesis through petrography, SEM-EDS, major and trace elements (including REEs), and sulfur isotope analysis. The sampled concretions occur in Upper Cretaceous-Paleocene marl layers from the Biban area, primarily in two main sectors (Koudiat Djebassa and Sidi Ziane), situated within the Southern Tellian Atlas in Northern Algeria (Maghrebides). While these barite concretions exhibit diverse morphologies, our analysis focuses specifically on oblate ellipsoidal concretions. The flattened shape of these concretions may stem from compressed echinoid tests or small, oblate septarian cracked concretions representing the flattened cores. Notably, these concretions feature an outer cortex of radial fibrous barite crystals, measuring centimeters in thickness. Petrographic examination coupled with SEM-EDS analysis suggests that concretion growth occurred from porewaters in unconsolidated, soft sediments at shallow burial depths beneath the sediment-water interface, manifesting in three growth episodes: (i) an initial stage characterized by primarily thin lamellar barite crystals intertwining to form rosette-like structures in concretion cores, (ii) a later stage marked by radial-fibrous barite crystal growth in concretion margins, and (iii) the filling of septarian cracks by barite. The presence of terrigenous sediment, particularly abundant in rosette-like barite crystals, indicates growth within highly porous sediment. Conversely, the radial fibrous outer cortex is related to an effective displacive growth mode. The δ34S values of the barite concretions (ranging from 16 ‰ to 24.4 ‰), consistent with seawater values, which document that seawater was the primary sulfur source. Furthermore, REE geochemistry further supports the seawater origin of diagenetic fluids rather than a hydrothermal one. Concretions are suggested to have formed in organic-rich, fine-grained sediments at shallow depth below the sea floor, in sedimentation halts, and as a result of microbial degradation of organic matter. Barium was supplied to porewaters within the methanogenic zone, precipitating as barite when, migrating upwards, reached the boundary with the overlying sulfidic zone. • We provide petrographical, SEM-EDS, major/trace elements, and sulfur isotope data on "septarian barite concretions" from Biban, north Algeria. • The results show that concretions formed at shallow depth below the sea floor during halts in sedimentation. • The oblate ellipsoidal shape of the barite concretions is due to the shape of the cores around which they grew. • REE geochemistry patterns reveal that concretionary growth is a result of diagenesis. [ABSTRACT FROM AUTHOR]

• K-Ar illite fault-gouge ages constrain the timing of the Wadi Kabir Fault at the Oman continental margin. • Fault-gouge ages of ∼95–85 Ma relate to contractional deformation and emplacement of the iconic Samail Ophiolite. • The age of 57.9 ± 2.0 Ma age corresponds with pronounced footwall cooling during the formation of the Bandar Jissah Basin. The complex structural geometry along the northern continental margin of Oman formed during polyphase deformation from the mid-Cretaceous to the Miocene. We focus on the kinematics and tectonics of the Wadi Kabir Fault, which represents an eastern segment of the large-scale, composite Frontal Range fault system that forms the northern boundary of the central Al Hajar Mountains. The most exhumed rocks outcrop in the Saih Hatat window of the Al Hajar Mountains, which occurs in the footwall of the Wadi Kabir Fault. To better understand the tectonic history of the Wadi Kabir Fault, we report three K-Ar illite fault-gouge ages. Sample FG16-1 from a shallowly north-dipping gouge zone of the eastern segment of the Wadi Kabir Fault yielded two consistent ages that overlap within 2σ uncertainties at ∼90 Ma. Sample FG16-2 from the central segment of the fault yielded a K–Ar age of 57.9 ± 2.0 Ma (2σ uncertainties), which is interpreted as a late Paleocene faulting event as it perfectly matches the cooling history of the high-pressure rocks of the Saih Hatat window in the footwall of the Wadi Kabir Fault. We present two tectonic interpretations for the ∼90 Ma fault-gouge age and prefer a synchronous kinematic relationship with the parallel and contractional mid-Cretaceous Yenkit Shear Zone that was active at the distal Arabian Platform since 114 Ma. Because the 57.9 ± 2.0 Ma age is associated with pronounced footwall cooling, we interpret this age to be related to the formation of the Bandar Jissah Basin in the hanging wall of the Wadi Kabir Fault. We conclude that the Frontal Range fault system likely formed during the Paleocene and that its young (≤∼43 Ma) history was accommodated along the western segment of the fault, as there is no evidence of this Eocene fault interval at the Wadi Kabir Fault. [ABSTRACT FROM AUTHOR]

The studied middle-upper Eocene Garet Gehannam section exhibits moderate macrofossil diversity and notably high macrofossil abundance. Eleven molluscan species were identified and described, including five bivalves and six gastropods. Three macrobenthic assemblages were recognized: The turritelline-dominated assemblage, Carolia placunoides assemblage and Turkostrea multicostata assemblage. The Turritelline-dominated assemblage indicates high-nutrient environments, which typically exhibit normal to slightly below normal marine salinities, low sedimentation rates, and high-energy environments. Carolia placunoides assemblage indicates brackish water environment during times of sea level regression. Turkostrea multicostata assemblage provides compelling evidence of a prevailing hot climate and an environment rich in calcium, characterized by nutrient-rich water and low to moderate energy levels and high light availability. The investigation of the articulation of Carolia placunoides Cantraine1838 and Turkostrea multicostata (Deshayes, 1818) shells strongly suggests a parautochthonous assemblage. In terms of paleobiogeography, Turkostrea multicostata (Deshayes, 1818) first appeared during the Paleocene in the southern Tethys, specifically in Tunisia and Algeria, as well as in the Trans-Saharan Seaway in Mali. Consequently, its paleobiogeographic distribution can be allied to current circulation along the Tethys Ocean, firstly from its original area in the southern Tethys regions and Trans-Saharan Seaway to neighboring regions of the southern and northern Tethys, as well as the West Africa provinces. The paleobiogeographic map of the identified species shows that the identified species were prevailing in two bioprovinces during the middle – late Eocene epochs: i) the North-West, North, and South Tethyan Margins Province, ii) and the West Africa Province. • Eleven molluscan species have been identified from the middle-late Eocene Fayoum succession. • The paleobiogeography of the identified species suggests an affinity with the Tethys region. • The macrofaunal assemblages suggest progress the shallow up conditions. • The migration routes of the identified molluscan species have been studied. [ABSTRACT FROM AUTHOR]

Paleocene deposits of the Subbetic Zone (southern Spain) provide outstanding evidence of the influence of sea mountains on deep marine currents. This part of the Betic Cordillera External Zones corresponds to the distal and deepest area of the original basin, where hemipelagic sedimentation prevailed during most of the Turonian-early Lutetian interval. This sedimentation is recorded by the so-called Capas Rojas and Quipar-Jorquera formations, units up to 250 m and 425 m thick, respectively, predominantly consisting of marls and marl/limestone alternations. These units draped and smoothed an irregular submarine topography of fault-bounded Mesozoic carbonate blocks. Some of these blocks became uplifted and subaerially exposed after a mid-Danian tectonic episode, transforming the Subbetic Zone in an archipelago during the late Danian-early Selandian interval. The emerged blocks were colonized by Microcodium -producing terrestrial plants, Microcodium consisting of aggregates of submilimetric monocrystalline calcite grains. Massive resedimentation of these grains into depressed zones of the archipelago resulted in discrete accumulations up to 100 m thick but of comparatively modest extent (≤150 km2) of calcarenites rich in Microcodium remains. The study of one of these calcarenite units, the Olivares Formation, demonstrates that most of its constituent Microcodium remains were brought to the deep sea by turbidity currents, but were subsequently reworked by oscillatory and unidirectional bottom-currents. The analysis of the Capas Rojas Formation in its type section and surrounding areas, where Microcodium -rich calcarenites are absent, demonstrates that the Danian-Selandian succession is riddled with hiatuses, which resulted in a drastic thickness reduction of the interval. Clearly, the rugged sea floor topography resulting from the mid-Danian tectonic event enhanced the sedimentary transport capacity of bottom-currents that, in addition to piling-up Microcodium -rich calcarenites in restricted zones, disturbed the hemipelagic sedimentation elsewhere in the Subbetic Zone. From late Thanetian times onwards the background hemipelagic sedimentation typical of the Capas Rojas progressively resumed throughout the Subbetic Zone, recording the gradual abatement of the sea floor relief by protracted erosion and/or subsidence. • Change of the bathyal Subbetic to an archipelago recorded by redeposited Microcodium • Pre- and post-archipelago weak deep-sea currents favored hemipelagic deposition. • The archipelago rugged sea-floor topography boosted the strength of deep-sea currents. • Deep-sea currents reworked calciturbidites and created hiatuses in hemipelagites. [ABSTRACT FROM AUTHOR]

Lacustrine fine-grained sedimentary rocks play a crucial role in the petroleum industry, particularly in the exploration of unconventional oil and gas resources. This study focuses on a petroliferous fine-grained succession deposited prior to the Paleocene–Eocene Thermal Maximum (PETM), specifically, the Paleocene second member of the Funing Formation. This formation represents the primary target for shale oil exploration in the Qintong Depression of the Subei Basin. Employing detailed sedimentological descriptions and utilizing multiple geochemical proxies, our investigation aimed to investigate lithofacies distribution and reconstruct the paleoenvironmental conditions prevalent in the Qintong Depression. Through the integration of lithological observation and well log data, the second member of the Funing Formation was categorized into three distinct system tracts: the early expanding system tract (EEST), the late expanding system tract (LEST), and the highstand system tract (HST). Within the established sequence stratigraphy framework, six lithofacies were identified, displaying comparable lateral and planar distributions. Results indicate that lithofacies exhibit greater thickness in the Deep Sag zone compared to the Slope and Fault Terrace. The EEST is characterized by laminated calcareous mudstone (LCM), laminated dolomitic mudstone (LDM), and massive argillaceous dolomite (MAD). Whereas the LEST predominantly comprises LCM and massive calcareous mudstone (MCM). These lithofacies were deposited under relatively arid climatic conditions, characterized by high salinity and strong terrigenous input, with a moderate abundance of organic matter consisting of type Ⅱ and type Ⅲ kerogen. In contrast, the HST is dominated by MCM with stable thickness, indicative of deposition under relatively humid climatic conditions with low salinity and terrigenous input. These conditions fostered an environment conducive to plankton and algae, resulting in a high abundance of organic matter composed of type Ⅰ kerogen. These new characterizations have significant implications for considering favorable lithofacies regarding the vertical orientation and target zones regarding the planarity of shale oil resources in the Qintong Depression of the Subei Basin. • The Paleocene second member of the Funing Formation is highly heterogeneous and moderately organic matter-rich. • The paleoclimate shifts from arid to humid, possibly linked to multiple hyperthermal events in the Early Paleogene. • The organic matter enrichment was influenced by changes of paleoclimate and redox conditions. • Laminated calcareous shale and dolomitic shale are the most favorable lithofacies in the second member of the Funing Formation. [ABSTRACT FROM AUTHOR]

The tectonic transition from oceanic subduction to continental collision is a fundamental process during orogenesis. Yet, the nature of this transition and its deep geodynamic processes for the southern Tibetan Plateau remain contentious. This study presents zircon U-Pb-Hf isotopes, whole-rock geochemistry, and Sr Nd isotopes for a quartz diorite intrusion and bimodal dykes from Dagze, combined with compiled data from the southern Lhasa subterrane, to reveal the geodynamic processes of late-stage of Neo-Tethyan subduction. Most of Dagze samples were emplaced between 66 and 64 Ma, while muscovite granite aplite dykes were emplaced between 64 and 60 Ma. They exhibit relatively uniform, depleted Sr Nd isotopes, with ε Nd (t) values ranging from +2.2 to +4.0, positive zircon ε Hf (t) values, and young depleted mantle model ages. Both exhibit compositional characteristics of subduction-related arc magma, marked by the enrichment of large ion lithophile elements and the depletion of high field strength elements. The mafic dykes with relatively low SiO 2 , high MgO, Cr, Ni, possibly originated from a fluid-metasomatized depleted mantle. The quartz diorite intrusion with low MgO, Cr, and Ni was generated by partial melting of sub-arc lithospheric mantle and experienced subsequent fractional crystallization of amphibole, clinopyroxene and orthopyroxene. The granitic dykes originated from partial melting of Gangdese juvenile crust and experienced fractional crystallization dominated by plagioclase. We suggest that the slab rollback and continental collision conjointly controlled the evolution of the latest Cretaceous to Paleocene Himalayan–Tibetan orogeny. Slab rollback of Neo-Tethys commenced around 70 Ma, triggering the partial melting of depleted mantle and juvenile crust, and this process resulted in the formation of Dagze diorites and bimodal dykes with arc affinity. • Diorite intrusion and mafic dykes originated from a fluid-metasomatized depleted mantle. • Granitic dykes originated from Gangdese juvenile crust and experienced fractional crystallization. • Slab rollback of the Neo-Tethys oceanic slab commenced around 70 Ma. [ABSTRACT FROM AUTHOR]

This contribution describes the influence of diapirism and compressional tectonics in the sedimentary record of the Estopanyà and Boix synclines (salt-walled basins) in the South-Central Pyrenees (NE Spain). Based on mapping and logging of five stratigraphic sections, two lithostratigraphic units (LU-1 and 2) along the eastern diapir margin of these synclines and five more (LU-3 to 7) in their inner parts are defined. LU-1 and 2 consist of monomictic breccias deposited probably during the Upper Triassic-Oligocene and the Upper Cretaceous, respectively. LU-3 to 7 constitute a marine to fluvial succession of the Tremp Group deposited during the Upper Cretaceous to Paleocene. The stratigraphic and sedimentological record indicates that the topography, position, and accommodation space of the Estopanyà and Boix synclines was actively controlled by the evolution of salt structures from the Late Cretaceous to the Oligocene in response to the advance of the Alpine compression in the South-Central Pyrenees. The growth of salt-inflated ridges with a near parallel orientation to the axis of the studied synclines since the Upper Cretaceous, progressively compartmentalized the Boix syncline until inhibiting sedimentation during the lower Paleocene. In the upper Paleocene, the Alpine compression approached the study area increasing salt evacuation and the subsidence of the Estopanyà and Boix synclines. During the early to middle Ypresian, onset of compression led to salt expulsion by piercing the sedimentary roof of the inherited salt-inflated ridges and forming two salt walls at the eastern margin of the Estopanyà and Boix synclines that were squeezed and welded (possibly through secondary welds) due to tectonic compression during the Oligocene. This contribution provides a new interpretation of the structural and stratigraphic evolution of the Estopanyà and Boix synclines, proposing an evolutionary model that includes the rejuvenation, growth, and extrusion of salt walls as deciphered from the stratigraphy, sedimentology, and petrology of the diapir margin breccias and the sedimentary succession of the adjoining salt-embedded basins. Hence, it provides a new analogue study for understanding the interplay between compressional tectonics, diapirism, and sedimentation to other inverted salt basins with precursor salt walls worldwide. • The sedimentary record of two adjacent synclines in the South-Central Pyrenees record the evolution during the Alpine compression of the adjoining salt walls. • Field and petrological data are combined to establish seven lithostratigraphic units and their significance for the evolution of the studied structures. • Three diapiric phases are established tracing an early salt inflation followed by a growth phase and an active diapirism during the compressive deformation onset. • The study constrains the evolution of a salt-walled basin in a fold and thrust belt, providing a new analogue for such basins. [ABSTRACT FROM AUTHOR]

The Paleocene hemipelagic deposits of the Dakhla Formation in Sinai offer an ideal setting to investigate paleoenvironmental fluctuations using benthic foraminifera. This study examined a Danian-Selandian sedimentary succession at Themed, Sinai using quantitative foraminiferal analysis within a sequence stratigraphic framework. Quantitative multivariate analyses, including R-mode clustering and non-metric multidimensional scaling (NMDS) ordination of biofacies trends and diversity parameters, indicate considerable paleoenvironmental and paleobathymetric changes throughout the studied succession. Five transgressive-regressive (T-R) sequences were identified based primarily on benthic foraminiferal biofacies trends. The sequence boundaries correlated well with major global sea-level lowstands. Benthic foraminiferal assemblages elucidated paleobathymetry fluctuations between upper bathyal and middle-outer neritic settings across the sequences. The identified sequences strongly correlate to global eustatic cycles, with subtle disparities suggesting a subordinate role for regional tectonics overprinting the dominant sea level control. The Latest Danian Event (LDE) interval coincides with the regressive phase of the fourth T-R sequence, as revealed from the biostratigraphic-constrained isotopic signature. It showed pronounced peaks in the relative abundance of the eutrophic buliminids, likely reflecting enhanced export productivity. Overall, benthic foraminifera provided vital paleoenvironmental insights, enabling sequence stratigraphic interpretation in the monotonous hemipelagites and highlighting possible coupled dynamics of both the carbon cycle and sea level. • Quantitative benthic foraminiferal biofacies enabled sequence stratigraphic interpretation. • Benthic foraminifera indicate fluctuations between bathyal and neritic settings. • Five transgressive-regressive 3rd order sequences were identified. • Sequences matched global eustatic cycles with slight regional tectonic overprinting. • Stressed benthic taxa indicative of perturbed conditions during the Latest Danian Event. [ABSTRACT FROM AUTHOR]

A detailed study of calcareous nannofossils was conducted on a well-exposed succession encompassing the Cretaceous-Paleogene (K-Pg) boundary interval at Wadi Nukhul, Sinai, Egypt, as a part of the southern Tethyan margin. The nannofossil biostratigraphic data show that the Nukhul succession sustains a complete K-Pg boundary interval. The nannofossil assemblage indicates a shift from cool/oligo-mesotrophic conditions in the late Maastrichtian Micula murus Zone to warm/oligotrophic in the latest Maastrichtian M. prinsii Zone prior to the K-Pg boundary. At the K-Pg boundary, diversity, and total abundance of the calcareous nannofossils remarkably decreased signifying unstable marine conditions. The post-impact assemblage (lowermost part of NP1 Zone) was marked by acme of Cervisiella operculata indicating oligotrophic conditions in the photic zone related to the diminished of the marine primary producers in the lowermost Danian. At the upper portion of the NP1 Zone, the assemblage is still dominated by C. operculata , besides the successive occurrence of the small-sized incoming Paleocene taxa Biantholithus sparsus and Neobiscutum romeinii. This pattern was accompanied by increased frequencies of Zeugrhabdotus sigmoides indicating stressful cool/meso-eutrophic surface water conditions signify the initial recovery interval. Upward in the early Danian NP2-NP3 zones, the nannofossil species diversity and total abundance progressively increased. Also, the nannofossil assemblage characterized by the existence of the new Paleocene oligotrophic indicators like Cruciplacolithus primus , Coccolithus pelagicus , and Ericsonia subpertusa. This probably indicates a tendency toward rebuilding of the biological pump efficiency and, therefore, a full recovery phase was resumed. • One complete stratigraphic section comprising the K-Pg boundary examined in detail. • Calcareous nannofossils reflect a remarkable turnover at the K-Pg boundary. • Cervisiella operculata acme in the survival interval indicating starving ocean. • Initial recovery was evidenced by the presence of the dwarfed Paleocene taxa. • Restoration of the biological pump was indicated in the early Danian NP2-NP3 zones. [ABSTRACT FROM AUTHOR]

• Palynozones make up two pollen assemblages attributed to upper Paleocene-early Eocene age. • Palynomorphs assemblage is dominated by angiosperm pollen grains. • The palaeoenvironmental is coastal swamp. A total of 72 samples from two wells (Ngata and Moulong) intersecting the N'kapa Formation of the Douala sub-basin were subjected to palynological analysis and yielded a rich assemblage of mainly terrestrial palynomorphs including Palmae pollens and dinocysts. Statistical analyses of the fossil counts led to the correlation of the two wells, outlining two informal palynozones: NpI inferred to be upper Paleocene in age with the first appearance datum of several late Paleocene pollen species such as Crototricolpites protoannemariae , Clavatricolporites leticiae , Clavatricolpites densiclavatus , Racemonocolpites racematus , Retitricolpites cf. simplex , Spathiphyllum vanegensis , and Ulmoideipites krempii. The early Eocene is inferred by the first occurrence of Retibrevitricolpites triangulates , characterizing NpII palynozone. Based on the presence and dominance of Palmae (Psilamonocolpites , Mauritiidites and Spinizonocolpites), Pteridophytes (Laevigatosporites) and Proteaceae (Echitriporites trianguliformis), a coastal swamp environment associated with a warm and humid climate is suggested. [ABSTRACT FROM AUTHOR]

As a crucial part of the Asian monsoon stretching from tropical India to temperate East Asia, the Indian monsoon (IM) contributes predominant precipitation over Asian continent. However, our understanding of IM's onset, development and the underlying driving mechanisms is limited. Increasing evidence indicates that the IM began in the Eocene or even the Paleocene and was unexceptionally linked to the early rise of the Tibetan Plateau (TP). These were challenged by the heterogeneous and diachronous uplift of the TP and all the reported records were confined to tropical zone under tropical monsoon driven by the Intertropical Convergence Zone (ITCZ) that is irrelevant to the TP. Therefore, reliable paleoclimatic records from the extra-tropical IM region is crucial to reveal how the tropical IM expanded to subtropical and temperate zones and what driving factors might be related to it. Here we present robust Eocene paleoenvironmental records from central Yunnan (~26°N) in subtropical East Asia. The multiproxy results of two sites demonstrate a consistent sudden switch from a dry environment in the early Eocene to a seasonally wet one at 41 Ma, suggesting a jump of the tropical IM to the southern subtropical zone at 41 Ma. The full collision of India with Asia, and the resulting changes in paleogeography at 41 Ma (closure of the Neotethys sea, retreat of the Paratethys seas, fast northward movement of the southern margin of the TP and rise of the central TP), aided by synchronous Antarctic cooling, might have worked together to drive the IM enhancement and northward expansion. [ABSTRACT FROM AUTHOR]

Based on their relatively large, chisel-like incisors and robust dentaries, species of the Paleocene plesiadapid mammal Chiromyoides have been described as potential ecological analogues of either seed-eating rodents or the unusually specialized lemur Daubentonia madagascariensis. Here, we analyze the most complete dentaries of Chiromyoides currently known in order to illuminate jaw form and function in this taxon. Principal Component Analysis shows that Chiromyoides campanicus and Daubentonia are uniquely similar in select dentary proportions when compared with a sample including seven other fossil plesiadapid taxa as well as 22 extant primates, dermopterans and scandentians. Comparative allometric analyses indicate that in both Daubentonia and Chiromyoides , the unique jaw proportions are likely achieved through hypertrophy of masseteric fossa length and dentary depth, rather than simple reduction of tooth row length. Consistent with these dentary features indicative of powerful gnawing, we show that incisor apex morphology became increasingly chisel-like in certain younger species of Chiromyoides. Importantly, slight reduction in molar area relative to jaw length and body mass appears to characterize all species of Chiromyoides in which molar proportions can be estimated. Notably, this pattern occurs in one of the oldest known specimens of Chiromyoides , an edentulous but relatively complete dentary from the middle Tiffanian of Texas, which differs from other Chiromyoides specimens in having a relatively shallower corpus. Taken together, this evidence suggests that Chiromyoides was a Daubentonia -like extractive forager that evolved from taxa whose diets emphasized exudates. [ABSTRACT FROM AUTHOR]

In 1909, the famous paleontologist Louis Dollo identified two putative new species of giant soft-shelled turtles from the lowest Eocene record of Belgium, ' Trionyx erquelinnensis ' and ' Trionyx levalensis ', from Erquelinnes and Leval, respectively. However, these proposals did not meet the requirements of the International Code of Zoological Nomenclature, so they were considered as nomina nuda. The information on these specimens or about any other specimen of this lineage of giant turtles from the Belgian record is currently extremely limited. Relatively scarce material from giant trionychids has been described for the lower Eocene record of other European regions. Considering the available information, all the European material has recently been recognized as belonging to the genus Axestemys , which has a North American origin, and possibly attributable to a single species, Axestemys vittata , which currently lacks a diagnosis. Numerous and well-preserved Belgian specimens are deposited in the Royal Belgian Institute of Natural Sciences. In addition to the cited individuals from Erquelinnes and Leval, additional specimens from both localities, as well as others from Orp-le-Grand, are part of this collection. These specimens, found between the decades of 1910 and 1930, have been recently restored, and their study is carried out here. The presence of Axestemys vittata in Belgium (in Leval and Orp-le-Grand) is confirmed. Knowledge about this species is significantly improved, and a diagnosis is proposed. However, the hypothesis proposed by Dollo is here confirmed, this species being not the only identified in the Belgian record. So, Axestemys erquelinnensis nov. sp. is defined based on the carapace from Erquelinnes known by Dollo, suggesting that the genus probably reached Europe during the Paleocene Eocene Thermal Maximum. [ABSTRACT FROM AUTHOR]

Paleogene mammal localities of North China are particularly well represented in the Erlian Basin, Inner Mongolia. Among them, the locality of Bayan Ulan is most famous for its late Paleocene Gashatan fauna. However, the younger Arshantan fauna of the same site is not well known, since no extensive study has been done so far. Here, we present a small mammal assemblage based on dental and tarsal material from a new Arshantan collection retrieved from the red beds of the late early to early middle Eocene Arshanto Formation at Bayan Ulan. It consists of at least six different taxa: the basal lagomorph Dawsonolagus antiquus , the large pantodont Pantolambdodon sp., the tapiroid Schlosseria magister , and the rhinocerotoids Hyrachyus crista and Rhodopagus guoi nov. sp. The assemblage is dominated by perissodactyls, especially Lophialetidae and Hyracodontidae. For the first time, p4-m1 of Dawsonolagus antiquus , tarsal material from Pantolambdodon sp., and lower dentition and tarsals of Hyrachyus crista are described and illustrated. Unlike other described Arshantan faunas, the Bayan Ulan Arshantan mammal assemblage has been collected exclusively from a single locality, which contributes to the reassessment of the misunderstood Arshantan Asian Land Mammal Age. [ABSTRACT FROM AUTHOR]

Early Paleogene vegetation units and their spatial distribution are reconstructed from the palaeobotanical record originating from 73 East Asian localities. A total of 79 microfloras and 31 macrofloras compiled from published sources are analyzed using diversity of plant functional types (PFTs). The spatial patterns obtained from the diversity of PFTs reflect the distribution of major early Paleogene ecosystems. As shown by the analysis different forest associations were most important with trees reaching over 50% of the total diversity in 96% of the localities. Using a data matrix with single PFTs, cluster analysis is performed to interpret the ecospectra of the fossil sites in terms of vegetation units according to their characteristics. As a result, the early Paleogene sites are allocated to four major groups including five subgroups, which can be interpreted in terms of seven vegetation units. The distribution of the units is shown on palaeogeographical maps. The early Paleogene vegetation cover in the study area fundamentally differed from modern, being much more homogeneous and thermophilous. In the early Paleocene, the dominant type of vegetation is typical mixed mesophytic forest (MMF). In the late Paleocene, a pronounced zone of MMF with diverse conifers appeared in high latitudes, the middle latitudes occupied by evergreens and typical MMF. In the early Eocene, MMF with diverse broadleaved evergreens and typical MMF are widespread and dominant. Early Eocene microfloras differ from Paleocene microfloras in the higher participation of temperate warm trees and in their higher contents in tropical PFTs. The early Eocene MMF with diverse evergreens thriving in the high and middle latitudes of East Asia is not equivalent to modern tropical vegetation and can be characterized as extra-tropical, based on the interpretation of their ecospectra. The reconstructed vegetation patterns are well in accordance with results obtained from the climate reconstructions indicating the existence of very warm high latitudes and a shallow latitudinal temperature gradient during the early Paleogene. • Dense forest cover existed at all the early Paleogene sites analyzed. • Vegetation confirms mainly warm temperate/subtropical climates with pronounced seasonality. • Equal importance of evergreen and deciduous PFTs is in agreement with the high global temperatures of the early Paleogene. • Constant presence of humid herbs and subtropical swamp trees coincides with the reported high humidity throughout the early Paleogene. • Early Paleogene vegetation cover fundamentally differed from modern, being much more homogeneous and thermophilous. [ABSTRACT FROM AUTHOR]

The second member of the Funing Formation (E 1 f2) is a Paleocene lacustrine organic-rich shale and has been identified as a primary source rock for both conventional and unconventional oil and gas in East China. It is correlated with the Early Late Paleocene Event (ELPE), a significant temperature inflection point in the Paleocene. However, the impact of the ELPE on the lacustrine organic-rich sedimentation is still not well understood. This study pinpoints the ELPE in the lacustrine E 1 f2 shale of the Subei Basin, identifies the resultant marine incursions by biomarkers, correlates the ELPE, marine incursions, and the depositional process, and clarifies organic matter accumulation mechanisms in the E 1 f2 shale. The interval preceding the ELPE has relatively low organic matter content, having been deposited in an arid paleoclimate with saline water conditions and low productivity. Eukaryotes predominantly contributed to the organic matter accumulation. The ELPE is identified in the E 1 f2 shale by negative carbonate carbon and oxygen isotope excursions. Subsequently, increasing temperatures and rising global sea levels induced marine incursions into the Subei Basin, supported by the appearance of 24- n -propylcholestane and the C 30 /C 27-30 steranes ratio. The interval following the ELPE shows relatively high organic matter content and was deposited in an arid to semihumid-semiarid climate and a saline to brackish waterbody. Marine incursions likely introduced nutrients and enhanced lacustrine productivity, as indicated by the consistency between signals of marine invasion and bioavailable nutrient elements. Different origins contribute to organic matter accumulation at this stage, with prokaryotes being more dominant than eukaryotes. The E 1 f2 shale provides valuable insights into lacustrine organic-rich sedimentary processes and the responses of lacustrine systems to global events. • The depositional environment of the Paleogene lacustrine shale was reconstructed. • The lacustrine depositional process was correlated with a global climate event. • The impact of marine incursions on shale deposition was dissected. • Organic matter accumulation models in the Paleogene lacustrine shale were established. [ABSTRACT FROM AUTHOR]

The Meirenfeng Formation, a critical Paleogene stratigraphic unit within the Yangtze Sag in the East China Sea Basin, has long suffered from uncertain age estimation due to limited paleontological evidence, which has consequently hindered regional stratigraphic correlation. This study employed zircon U–Pb age dating through the LA-ICP-MS method to two tuff samples extracted from the CJ-2 well. The obtained ages are approximately 61.0 ± 1 Ma and 62.25±1 Ma, respectively, which confirms the sedimentary age of the Meirenfeng Formation as Paleocene Danian-Selandian. This age directly correlates it to the Paleocene Yueguifeng Formation in the Lishui-Jiaojiang Sag, a confirmed source of hydrocarbons. In addition, geochemical investigations conducted on the shale samples from the Meirenfeng Formation indicate a medium to good abundance of organic matter and a kerogen type of III. The regional seismic profile further reveals that the Meirenfeng Formation in the Yangtze Sag extends continuously to the Zhedong Depression, boasting a maximum residual thickness of up to 2000m. This suggests a similar Paleocene period of extensive stretching and rifting in the Zhedong Depression. This research offers the first robust age estimation for the Meirenfeng Formation in the Yangtze Sag, providing an essential geological foundation for accurate tectonic history reconstruction, Paleocene stratigraphic subdivision, regional correlation, and hydrocarbon prospectivity assessment within the East China Sea Basin. • The absolute age determined for the Early Paleocene Meirenfeng Formation in East China Sea Basin. • The Meirenfeng Formation can be correlated to the proven source rocks, Yueguifeng Formation. • Coeval rifting occurred in the Zhedong Depression and Taibei Depression during Paleocene period. • Thick Paleocene preserved in Zhedong Depression could be another potential hydrocarbon source rocks. [ABSTRACT FROM AUTHOR]

The tectonic evolution of the Mozambique Basin was controlled by the break-up of Gondwana which led to the development of extensional domains along the East African margin. As a result, multiple grabens systems were formed both onshore and offshore southern Mozambique. Two of them are the Palmeiras and Xai-Xai grabens, which are discussed in greater details in this study using an extensive seismic dataset, together with regional gravity and magnetic data. The data show that the Palmeiras Graben evolved from a single extensional phase in the Middle to Late Jurassic (Kimmeridgian?). In contrast, the Xai-Xai Graben records three extensional phases. The first extensional phase occurred in the Late Jurassic (Tithonian?) to Early Cretaceous (Berriasian), the second during the Aptian-Albian and the third in the Late Miocene. The tectonic evolution of these grabens strongly controlled their sedimentary infill during Late Jurassic and Early Cretaceous rifting. Volcanism associated to these tectonic events is documented by onshore and offshore boreholes, as well as by the presence of buried volcanic bodies, lava extruded along fault planes and intrusions of Mesozoic age. Furthermore, a volcano-sedimentary sequence and dome type volcanoes were imaged in seismic data. Differences in tectonic activity impacted the oil and gas potential of both the Palmeiras and Xai-Xai grabens. The sedimentary sequences deposited in the Palmeiras Graben were preserved due to a period of relative tectonic stability predominating from the Aptian to the present day. The burial of the Palmeiras Graben during this period of tectonic stability under a thermal subsidence favoured the generation and preservation of hydrocarbons. In contrast, the Xai-Xai Graben was impacted by intense tectonics, which led to a limited or restricted deposition of strata since the Late Cretaceous to the Paleocene – Early Eocene. As a consequence of a long lasting tectonic activity in the Xai-Xai Graben, uplifting and erosion of potential reservoirs and destruction of existing traps, impacted on the prospectivity for hydrocarbons. • Gondwana break-up led to the development of extensional domains along the East African margin. • Grabens systems were formed in both MCP and MB. • Two of them are the Palmeiras and Xai-Xai grabens. • Palmeiras Graben evolved from a single extension while the Xai-Xai Graben was formed during three extensional phase. • Tectonic events strongly influenced their sedimentary infill during Mesozoic. [ABSTRACT FROM AUTHOR]

Due to the lack of deep wells in the broader region, the mud volcanic deposits (mud breccia) are the only source of direct information for the deep stratigraphic units of the Mediterranean Ridge (MR), in the eastern Mediterranean. The study of this material, combined with the available seismic data, can improve the geological understanding of this frontier exploration area. In this paper, biostratigraphic and geochemical studies are performed on mud breccia deposits from five Mud Volcanoes (MVs) in the central MR, aiming to define the sediments' stratigraphic origin and assess the source rock potential of the individual formations. In addition, regional seismic data is used to reveal the spatial distribution of the major lithostratigraphic formations in the subsurface. Results indicate an Eocene-Miocene origin for the mud breccia of Gelendzhik, Nice, Moscow and Dublin MVs, whereas a Paleocene (?) and Cretaceous origin is suggested for the Toronto MV deposits. Most clasts represent hemipelagic mudstones/marlstones. Regarding the source rock potential of the area, it is considered that: (a) nine clasts of Miocene, Eocene and undetermined age, reflect the presence of immature and early mature, gas-prone source rocks of poor to moderate potential; (b) a small clast discovered in the matrix of Dublin MV originates from an excellent quality oil-prone source rock; and (c) the discovered solid hydrocarbons and oil droplets point to an active petroleum system in the region. Seismic interpretation defines the spatial distribution of the Post-Evaporite, Evaporite and Pre-Evaporite formations. The burial depth of the Pre-Evaporite formation (source layers of MV deposits) significantly varies from 20 to 4970 m inside the study area and is largely dependent on Evaporite thickness. • Seismic interpretation suggests 3 main formations (Post-Evaporite, Evaporite and Pre-Evaporite Fms). • Micropaleontological analysis reveals a Cretaceous to Tortonian origin for the mud breccia (Pre-Evaporite Fm). • Rock-Eval & organic petrographyanalysis reveal a poor-excellent oil/gas potential, both immature and oil window mature. • The discovered solid hydrocarbons and oil droplets point to an active petroleum system in the region. • The burial depth of the Pre-Evaporite formation varies from 20 to 4970 m in the study area. [ABSTRACT FROM AUTHOR]

The known fossil record of crocodyliforms in Europe during the Paleogene is significantly biased, in that the fauna of Western Europe is far better sampled and understood compared to that of Eastern Europe. We describe in detail all known crocodyliform remains from the middle Eocene (Lutetian) Ikovo locality in Ukraine. We conclude that at least two taxa were present: a moderate to large-sized Tomistominae indet. similar to the basalmost known tomistomines, and the small-sized basal alligatoroid cf. Diplocynodon sp. Despite its scarcity, this is the first basal alligatoroid material reported from Eastern Europe (as part of post-Soviet countries) and the easternmost record of diplocynodontines in Europe so far. An allegedly freshwater cf. Diplocynodon sp. contributes a rare faunal element to the vertebrate assemblage of the Ikovo locality, otherwise dominated by resident or facultative marine taxa. The fossil record and historical paleobiogeography of crocodyliforms from the Paleocene and Eocene of Europe are reviewed. As it has been already known, the middle Eocene fauna of crocodyliforms proves to be taxonomically diverse and complex. Its constituent lineages geographically originated in Asia or North America (Diplocynodontinae, Asiatosuchus -like crocodyloids, Planocraniidae), North America (derived alligatorines), Africa (Tomistominae), and Gondwana (ziphodont mesoeucrocodylians Iberosuchus and Bergisuchus), with possible subsequent speciation in Europe. We propose a novel hypothesis of Asian origins of European diplocynodontines, which will be explicitly tested in future studies. The revealed similarities between crocodylians and turtles from the Ikovo locality and those from Western Europe support the presence of a single Pan-European biogeographical zone during the middle Eocene, distinct from that of Asia. [ABSTRACT FROM AUTHOR]

The Late Cretaceous–early Paleogene interval is globally associated with transient to long-term changes in the stable carbon isotopic composition of marine carbonates (δ13C carb). Based on biostratigraphic reconstruction, this critical period of Earth's history is thought to coincide with the deposition of world heritage Paleocene phosphate deposits (phosphorites) in northwestern Morocco. However, the detailed stratigraphy of the Gantour basin, one of the most important Moroccan phosphate deposits, has not yet been constrained. For instance, the former "Montian" Stage has been used to tentatively approximate the Danian, whereas the succeeding Selandian Stage remains to be identified. Here, we develop a detailed organic carbon isotopic (δ13C org) curve from phosphorus-rich horizons of the western Gantour sedimentary sequence in an attempt to constrain their stratigraphic placement and depositional age model. Upsection, these strata host long-term negative and positive δ13C org trends that tend to correlate with global δ13C carb records of the Cretaceous–Paleogene and mid-Thanetian transitional boundaries. The data support the presence of Danian and Selandian rocks in the Gantour basin, which are succeeded by strata containing characteristic signatures of the well-known Cenozoic δ13C maximum at 58–57.5 Ma (the Paleocene Carbon Isotope Maximum). Our results shift the previously proposed Cretaceous–Paleogene transition in the Gantour basin further down into the older sediment C2M layer without interfering with recorded massive biological turnover in faunal diversity and abundance. Moreover, the refined stratigraphy suggests that the deposition of the Gantour phosphorites spanned ∼8.5 Myr. Our results confirm the utility of δ13C org chemostratigraphy for dating and correlating phosphate-bearing deposits of the Tethyan province. They have important implications for deciphering Paleocene phosphogenesis, the co-evolution of associated vertebrate groups, and for prospecting phosphorus-rich mineral deposits. • Datation of phosphate-bearing sequences from the Moroccan western Gantour basin. • δ13C org chemostratigraphy is an appropriate correlation tool. • The refined stratigraphy implies at least the presence of Danian, Selandian, and mid-Thanetian rocks. • Phosphate deposition over a ∼ 8.5 Myr long time period. [ABSTRACT FROM AUTHOR]

The timing, kinematics, and geodynamic evolution of the India-Asia continental collision are crucial to understanding the geological and geomorphological evolution of the Himalayan-Tibetan orogen. However, the debate over how and when the collision occurred persists due to disputes concerning the reliability of paleomagnetic data obtained on both sides of the suture zone. This paper presents a comprehensive analysis and evaluation of paleomagnetic studies to address this controversial issue. The study focuses on well-preserved Cretaceous-Paleocene rocks from the Lhasa and Tethyan Himalaya (TH) terranes over the past two decades. We conclude that: (1) the paleomagnetic data of the Linzizong Group of the Lhasa Terrane and the Zongpu Formation of the TH are in their primary origin and can be used for tectonic reconstruction; (2) the Tethys Himalaya Basin (THB) was generated due to the rifting of the TH from Greater India before the Late Cretaceous; (3) the southern margin of Asia was aligned in the NW-SE direction before the India-Asia collision. The study suggests a quasi-synchronous multi-stage collision where the TH collided with the Trans-Tethyan subduction system in Late Cretaceous-Early Paleocene times (∼65 Ma), followed by collision with Asia at 56–59 Ma. Finally, the India Craton collided with the TH, resulting in the synchronous closure of the THB at approximately 40 Ma. [ABSTRACT FROM AUTHOR]

Mercury (Hg) concentrations and Hg isotopes have been widely used to fingerprint geological volcanism. Mercury content, as a more accessible proxy, is more frequently used than mercury isotopes. With the deepening of research, however, it has been found that the Hg content of sediments can be strongly heterogeneous. The Paleocene–Eocene Thermal Maximum (PETM) was likely at least in part driven by magmatic activity based on multiple proxies, but existing PETM Hg records can be complex and sometimes ambiguous. To gain a global overview of the temporal and spatial distribution of Hg enrichment during the PETM, a compilation of new and existing mercury and associated data across this event from 19 globally distributed sites has been analyzed. Our findings indicate intercontinental Hg enrichment in the late Paleocene (∼120 kyr prior to the PETM). Hg further increased ∼30 kyr before, and within the onset of, the PETM carbon isotope excursion (CIE), supporting significantly increased volcanic Hg release and/or thermogenic Hg release via hydrothermal vent complexes (HTVCs) as the key trigger of the PETM. Evidence for magmatic activity during the CIE body is more complex and equivocal, and there is a general decline in Hg enrichment in the latter part of CIE body. This decline may indicate a decrease in volcanism, in-line with the general lack of tephra deposits close to the NAIP, and implies a decrease in highly explosive events capable of dispersing ash (and Hg) significant distances. Toward the end of and after the CIE, abundant tephras in the area proximal to the NAIP are contemporaneous with low Hg, suggesting a likely change in magmatic style and Hg flux, and emphasizing complexity in the expression of magmatism in sedimentary Hg data. • Global compilation of Hg data indicates that onset of PETM was associated with volcanism. • Intercontinental Hg enrichment began ∼30 kyr before the PETM. • Decreased Hg enrichment during the PETM may indicate a decrease in volcanism. • Conflicting evidence for volcanism from Hg, Hg-isotopes and ashes highlight complexity of magmatism. [ABSTRACT FROM AUTHOR]

The Himalayan orogen is an archetype of collisional orogens built by the continental collision between India and Asia in the Cenozoic, and it has been a natural laboratory for studying the tectonic evolution of continental collision zones. Various tectonic models have been proposed to interpret the formation and evolution of the Himalayan orogen. However, these models were primarily based on local observations of structural geology and petrology, and some of these models even contradict to each other. The widespread exposure of metamorphic rocks and their metamorphic features are crucial aspects for reconstructing the tectonic evolution of the collisional orogen, as it provides robust records of metamorphic pressure (P) and temperature (T) at different ages. In this study, we present a systematic review on the metamorphic features of crustal rocks from the Western through the Central to the Eastern Himalayas. In doing so, we outline the spatial and temporal changes of metamorphic features (including P – T paths and T/P ratios) at first and then discuss their tectonic implications. In general, the metamorphic evolution of the Himalayan orogen can be categorized into three periods: (1) pre-collisional period from the Early Jurassic to Paleocene, which is represented by low T/P Alpine type metamorphism forming high-pressure (HP) blueschists in the Western to Central Himalayas; (2) syn -collisional period from the Paleocene to Eocene, which is divided into two stages. The early stage from the Paleocene to early Eocene is characterized by continental deep subduction at low T/P ratios to form Alpine type HP to ultrahigh-pressure (UHP) eclogites in the Western Himalaya, whereas the late stage from the early to late Eocene is characterized by continental hard collision at medium T/P ratios to form Barrovian type medium-pressure (MP) amphibolite and HP granulite in the Central to Eastern Himalayas; (3) post-collisional period from the Oligocene through Miocene to Pliocene, which is also divided into two stages. The early stage during the Oligocene is represented by continuous metamorphism at medium T/P ratios. Tectonic reactivation for the transition from the moderate to high T/P metamorphism would occur locally in the early stage, but became extensive in the late stage when metamorphic T/P ratios were high enough to cause intensive anatexis in the Miocene, giving rise to Buchan type HT to UHT metamorphic rocks in the Central to Eastern Himalayas. The inspection of different metamorphic facies series throughout the entire Himalayan orogen indicates that the Indian continental crust was collisionally thickened at first and then underwent large-scale reworking through intracontinental extension in the post-collisional period. The deep subduction of oceanic and continental crust is characterized by Alpine type metamorphism at low T/P ratios, the continental hard collision is represented by Barrovian type metamorphism at medium T/P ratios, and the post-collisional reworking is indicated by Buchan type metamorphism at high T/P ratios. The difference in metamorphic T/P ratios is spatiotemporally distinguishable in the Himalayan orogen, documenting the tectonic transition from oceanic subduction through continental subduction and collision to post-collisional rifting along the convergent plate margin. Therefore, the secular change of metamorphic T/P ratios can be used to retrieve the change of geothermal gradients and dynamic regimes from syn -collisional compression to post-collisional extension in the lifetime of the convergent continental margin. As such, the orogenic wedge is a holistic model for the spatiotemporal occurrence of Himalayan sequences cross the collisional orogen, and the failed continental rifting is a viable mechanism for high T/P metamorphism and granitic magmatism in the intracontinental orogen. • Secular change of metamorphic thermobaric ratios during the Cenozoic is evident in the Himalayan orogen. • The Indian continental crust was deeply subducted to mantle depths in the Western Himalaya. • The Indian continental crust was significantly thickened during collisional compression in the Central and Eastern Himalayas. • The collisional orogen became an intracontinental orogen through active rifting in the post-collisional period. • The orogenic wedge is a holistic model for the formation and evolution of the Himalayan orogen. [ABSTRACT FROM AUTHOR]

Mercury (Hg) records in marine and terrestrial archives across the Cretaceous/Paleocene (K/Pg) boundary were examined as a proxy for Deccan Large Igneous Province (LIP) eruptions. We examined no less than twenty-six key sections/boreholes that are globally distributed, and show that Hg values have a log-normal distribution. The data have a similar trend to that across other major extinction boundaries in the Phanerozoic record. Questionable Hg/TOC anomalies have been ruled out, indicating excess Hg loading at the K/Pg boundary. Most Hg isotope values across the K/Pg boundary indicate a volcanic Hg source, based on the mass-independent (MIF) Δ199Hg values. However, negative Δ199Hg values suggest continental inputs in the Jhilmili section (India). Near-synchronous Hg and negative carbon-isotope excursion (CIE) patterns are identified in sediments associated with LIPs representing the paired release of Hg and isotopically depleted CO 2 , especially in the Latest Maastrichtian warming event (LMWE) that we attribute to the Deccan LIP. We compared the response of global biotic changes to Deccan volcanism and the Chicxulub impact. It appears that the end-Cretaceous mass extinction was a complex catastrophe caused by volcanism driving major climate fluctuations and ocean acidification, and perhaps exacerbated by the Chicxulub impact. [ABSTRACT FROM AUTHOR]

Paleoclimate reconstruction and aeolian deposits in China indicate a major environmental reorganization – the formation of a nonzonal monsoon-dominated climate pattern – in East Asia in the late Oligocene and the early Miocene. In contrast, a zonal planetary-wind-dominated climate pattern has prevailed during the Paleocene and Eocene. However, this classical paradigm describing the climate transition has been questioned by recent studies. Here, our study emphasizes the importance of considering orbital-scale climate oscillations to better understand and reassess the paradigm. By examining the halite and mudstone sequence in the Jianghan Basin and conducting numerical experiments using the Norwegian Earth System model, we propose the concept of a "green Yangtze" phenomenon, which utilizes orbital-scale climate oscillations to reconcile the wet and dry environmental indicators in Eastern China during the Paleogene. It is essential to differentiate the Paleogene climate, characterized by intense orbital-scale wet and arid oscillations, from the Neogene monsoon-dominated climate. The classic paradigm remains valuable in understanding the long-term mean environment, albeit without capturing the orbital-scale details. Future research should focus on uncovering orbital-scale variations to enhance our understanding of climate evolution and dynamics in East Asia during the Cenozoic. • The paradigm of Paleogene zonal and Neogene nonzonal climate patterns captures Cenozoic East Asian climate evolution. • Orbital-scale oscillations are crucial in differentiating the climate during the Paleogene and Neogene. • A green Yangtze phenomenon reconciles Paleogene wet and dry environmental indicators in Eastern China. [ABSTRACT FROM AUTHOR]

The Koum Basin is one of major intracontinental basins in northern Cameroon. It is part of the Upper Benue Trough and has genetic ties to the West and Central African Rift System. The main purpose of studying the Koum Basin sedimentary deposits was to re-examine the time of the deposition and constrain the palaeoenvironmental and paleoclimatic conditions during deposition. To accomplish this, we used a combination of sedimentologic, palynologic, mineralogic, and geochemical data. Claystone units interbedded with calcareous siltstones dominate sedimentary sequence, including few clay beds, fine to medium-grained sandstone, and rare marl layers. The palynomorph assemblage suggests a previously unknown Maastrichtian – Paleocene age in this basin. The sediments originated from intermediate igneous parent rocks with a relative contribution of felsic rocks. These rocks underwent low detritism (Si/Al: 2.51–4.43; K/Al: 0.11–0.36; Ti/Al: 0.05–0.10) and chemical weathering (CIA: 55–64; PIA: 56–68) in the source region. Consequently, deposits are immature (ICV values > 1) and weakly recycled (Si 2 O 3 /Al 2 O 3 ratios ≤5). The organic matter analysis and the palynoflora assemblage, reveal Type III kerogen with significant contributions of Type II-III and type II kerogens, as well as a continental paleo-depositional environment with open rainforest to savannah vegetation. The clay minerals distribution suggests moderate illitization and chloritization processes and thus moderate burial diagenesis at temperatures ranging from 70 to 90 °C, also attested by immature to mature Tmax values (≤436 °C) marginally. The low CIA values and very low kaolinite contents, indicate dry climatic conditions. In addition, two major-element-based discrimination diagrams show that the parent rocks of clastic sediments formed primarily in a continental arc system, with a moderate contribution from the rift system and a low contribution from the oceanic island arc, implying compressional conditions, which is consistent with previous studies on the tectonic background of the region during the late Maastrichtian to Paleocene period. • The first Maastrichtian – Paleocene record from the Koum Basin, Upper Benue Trough, northern Cameroon. • Illitization and chloritization processes point moderate burial diagenesis, and immature to marginally mature organic matter. • Pollen and spores, clay minerals, and CIA all hint to a semi-arid environment with open rainforest to savannah vegetation. • Compressional tectonic conditions were discovered in the Koum Basin at this period. [ABSTRACT FROM AUTHOR]

The space-time analysis of the evolution of Cretaceous-Paleogene magmatism by Díaz-Bravo et al. (2022), identifies the development of a continuous magmatic arc along the continental margin, contradicting the migration of the arc towards the continent as a consequence of flattening of the Farallon plate (Damon et al., 1981). This magmatism was developed simultaneously in the interior of the continent and interrupted during the Paleocene. Consequently, our conclusions are not an adaptation of magmatic ages in the context of planar subduction as suggested by Chávez-Cabello and Ramírez-Peña (2023). Including U–Pb ages from a few missing Cretaceous plutons in our analysis do not change our model at all but enrich it. The study of regional deformation was not part of the objectives of our work, but we pointed out some issues about the temporality of magmatism and deformation previously documented, trying to prevent future misinterpretations. We show here that magmatism was emplaced at the beginning and end of the Late Cretaceous deformation phase of the Mexican Fold and Thrust Belt, and it was absent during the Paleocene-Eocene deformation stage. We ruled out tectonic transport of the Cretaceous plutons, or we think that it should be negligible considering how far (hundreds of kilometers) are these and other plutons from the paleo-trench. Furthermore, plutons such as Pico de Teyra were not located in the thin-skinned cover and others such as El Milagro and La Pólvora do not present deformation features. A large syn-tectonic displacement scenario should be changed dramatically the texture of these rocks, but large parts of these plutons preserve magmatic textures and some of them do not show evidence of deformation. Also, is very likely that the P-T conditions in such large transportation, would induce recrystallization and resetting of some isotopic systems (i. e., K–Ar) but it is not observed or has not been documented. We highlight the contributions we have made to the knowledge of the intracontinental plutons studied and the adequate documentation of our work. Finally, we insist that pre-Mesozoic basement is little known in the study area, despite the documented geophysical data. • Cretaceous-Paleogene magmatism was established on the continental margin near the paleo-trench and landward. • Magmatism was emplaced at the beginning and end of the Late Cretaceous deformation phase of the Mexican Fold and Thrust Belt. • Most Late Cretaceous plutons in central Mexico preserve magmatic textures without deformation features. • Several models of planar subduction could explain the origin of magmatism related to the Farallon plate subduction. [ABSTRACT FROM AUTHOR]

• Six new C 2 -DBFs are tentatively identified. • DBFs and BNFs can be used as paleoclimate indicators. • DBFs can be used as a source rock age diagnostic correlation tool. Dibenzofuran, benzo[ b ]naphthofurans and a series of their alkylated isomers were identified in coal, coaly shale, and shale extracts from the Gippsland Basin (Victoria, Australia). The dibenzofuran series include C 0 -C 4 dibenzofurans, and the benzo[ b ]naphthofuran series are composed of benzo[ b ]naphthofuran, methylbenzo[ b ]naphthofurans, and possible dimethylbenzo[ b ]naphthofurans. Seventeen C 2 dibenzofurans isomers (including six new isomers) were tentatively identified in rock extracts from the Gippsland Basin. The distribution and contents of C 0 -C 4 dibenzofurans are different for Eocene and Paleocene rocks, providing a source rock age diagnostic correlation tool. Biological origin is the main factor that controls the abundance and distribution of dibenzofuran, benzo[ b ]naphthofuran and their alkylated isomers, based on investigation of source-, environment- and maturity-derived parameters. Variations in the C 1 dibenzofurans/dibenzofuran ratio and the benzo[ b ]naphtho[ 2,1-d ]furan/benzo[ b ]naphtho[ 1,2-d ]furan ratio may reflect local paleoclimate changes in the Gippsland Basin. [ABSTRACT FROM AUTHOR]

Unraveling the rifting history along the southeastern margin of the South China Block has important implications for establishing the origin and evolution of the South China Sea (SCS). However, the onset time of rifting associated with the opening of the SCS remains unclear. The Littoral Fault Zone is the largest boundary fault between the South China Block and the SCS, and its fault activity provides information about the evolutionary history of the SCS and crucial constraints on the opening of the SCS. Here we present new apatite (U Th)/He (AHe) ages obtained from the Sunset Peak and Tai Mo Shan, Hong Kong, along the footwall of the extensional Littoral Fault Zone, to constrain the timing of fault activity. The AHe age-elevation relationships and thermal modeling results document an accelerated exhumation during ∼60–55 Ma, which we interpret to be associated with extensional movement along the Littoral Fault Zone. The activity of this extensional fault at ∼60–55 Ma is considered to be coeval with the initial deposition of conglomerate at the bottom of the Pearl River Mouth Basin in the hanging wall of the Littoral Fault Zone. Integration of thermochronological data, magmatic characteristics, and seismic and drilling data support that the Paleocene extension occurred widely in the southeastern margin of the South China Block, representing a prelude to the seafloor spreading in the SCS. • New apatite (U Th)/He data in Sunset Peak and Tai Mo Shan, Hong Kong. • Accelerated exhumation at ∼60–55 Ma in response to extension of the Littoral Fault. • Paleocene regional extension is the preclude to the opening of the South China Sea. [ABSTRACT FROM AUTHOR]

The palaeoecology of Ginkgo through deep time, including its ecophysiology and heterophylly, remains poorly understood due to the limitation of quantitative methods. In this paper, we report well-preserved leaves of Ginkgo henanensis sp. nov. from the Paleocene Dazhang Formation of Luanchuan, Henan Province, China. Our understanding of the ecophysiology and heterophylly of the genus has been improved by the discovery. These fossils are distinguished by heterophyllous leaves that can range in morphology from bilobed to multi-lobed forms. Thus, unlike other Cenozoic Ginkgo with entire-margined leaves, this is the first well-established Cenozoic taxon that has exclusively lobed leaves similar to Mesozoic-type ginkgos. A useful leaf ecophysiological functional trait that offers quantitative insights into morphological heterophylly and the mechanism of leaf shape selection is the dry leaf mass per area (LMA) of Ginkgo. Leaf shape changes, including the evolution of heterophylly, are linked to functional adaptation. There are two groups of LMAs for four fossil G. henanensis specimens: 120.9 g/m2 to 131.3 g/m2, and 184.5 g/m2 to 187.4 g/m2. The results of the reconstructed fossil LMAs, which serve as quantitative evidence of G. henanensis ' heterophylly, also point to the existence of various leaf survival strategies within G. henanensis. Additionally, both groups of G. henanensis have LMAs that are higher than those of extant Ginkgo biloba , indicating that this species has a slower return ecological strategy than its current equivalent. This strategy may have helped to decrease the rate of nutrient cycling, which supported Ginkgo to thrive in a wider variety of ecological niches in the Paleocene than it does today. These findings close a knowledge gap in the evolution of Ginkgo. • Species similar to the Mesozoic multilobed Ginkgo still present in the Paleocene. • The feasibility of existing methods to reconstruct the leaf mass per area of fossil Ginkgo is tested. • Heterophylly of fossil Ginkgo are quantitatively proved. [ABSTRACT FROM AUTHOR]

Sub-surficial models predict the occurrence and geometry of strata, geological structures, inclusions, tectonic settings and so on. Robust data including geologic information, airborne gravity, and magnetic data, with constraining drill–depth data are here integrated to model the topography of the basement that underlies the Niger Delta sedimentary sequence. The aim was to elucidate the existence of a petroleum system from the unexplored depths of the delta near the basement, hypothetically controlled by the basement structures. Airborne total magnetic intensity (TMI) and Bouguer gravity anomaly (BGA) of the Niger Delta, obtained from the Nigerian Geological Survey Agency that were noise–filtered and corrected are used. The gradient of the geomagnetic field was removed from the magnetic data and the data was reduced to the equator (RTE). As precursory operations, sub-surficial lineament structures were delineated from these grids using the Tilt Derivative filters, and the depths were determined using the Source Parameter Imaging (SPI) technique. Subsequently, basement topography models were generated across four (4) profiles in a gravity-magnetic joint inversion scheme. Consequently, the strata that constitute the Niger – Delta 'cake' from the Cretaceous to Recent were modeled. The results showed that the Late Cretaceous Synrift Clastics (LCSC) formation presumed to directly overlie the basement may vary in thickness from 2.15 to 2.74 km. The lineament structures were found to dominantly trend in NE – SW direction. The depth to the basement, from the 2-dimensional models, ranges approximately from 13.18 to 19.35 km. It is postulated that while the Tertiary Niger Delta is characterized by lineaments engendered by diapiric instability of the over–pressured Paleocene – Pliocene marine shales, there exist other lineament structures beneath with NE – SW as the dominant trends, offshoots of Mid – Atlantic fracture zones including Chain and Charcot. Basement undulations, which are relicts of the vast subsidence Passive margins undergo during their formation are observed. These resultant synclinal structures create accommodation for the extensive deposition of the LCSC. The juxtaposition of this reservoir facie, the lineament-laden undulating Passive basement escarpment, and, the Paleocene – Pliocene Marine Shale formation could make for another petroleum system. • Lineament structures were delineated and trend dominantly in the NW – SE, NE – SW, and, N – S directions. • Depth values delineated from the BGA range from 0.9 to 9 km and RTE – TMI anomaly ranges from 3 to 23 km. • The Late Cretaceous Synrift Clastics (LCSC) formation directly overlying the basement escarpment range in thickness from 2.15 to 2.74 km. • The depth to basement values from the 2-D models range from 13.18 to 19.35 km. • Basement undulations, which are relicts of the vast subsidence Passive margins undergo during their formation, are observed. [ABSTRACT FROM AUTHOR]

Lower Paleocene marine siliciclastics of the Sobral Formation (Seymour Island, Antarctica) form an important component of a key southern high latitude reference section for the Maastrichtian–Eocene. The formation comprises a coarsening-upward, regressive succession (270 m thick), shallowing from prodeltaic, mud-rich to sandy nearshore sediments. Sedimentary facies analysis, integrated with macrofaunal and microfloral palaeoecological studies, indicate a wave-dominated, tidally influenced deltaic environment. Four depositional sequences (1–4) record the role of relative sea-level changes in controlling the stepwise progradation of the system. Prodeltaic and distal delta-front deposits (Sequences 1, 2), comprise coarsening-upward parasequences of mud-rich heteroliths and bioturbated fine-grained muddy sands displaying draped slump scars. The overlying erosional sequence boundary is marked by incised valleys filled with fluvio-estuarine sediments; succeeding sand-rich facies (Sequences 3, 4) represent the proximal delta front and delta platform. The macro-invertebrate and palynological datasets display contrasting responses to the regressive history of the formation. The macrofaunal record in the distal deltaic sediments reflects the marine influence, though a stratigraphic increase in diversity was controlled both by ecological factors and biotic recovery following the K–Pg event. The associated palynological assemblage also displays a strong marine signal and includes typical outer neritic – oceanic dinoflagellate cyst taxa. A sharp decline in macrofossil diversity and abundance in Sequences 3, 4 is compatible with ecological stress in shallow-water, restricted inshore settings. Though the palynological record at this level is terrestrially dominated, the marine component reflects the cosmopolitan nature of dinoflagellates, displaying the highest diversities in the formation. The regressive Sobral Formation ended a protracted c. 60 Myr history of regional subsidence and marine sedimentation; although amplified by two Danian sea-level falls of probable eustatic origin, the regressive trend heralded mid-Paleocene basin inversion potentially linked to the onset of regional tectonic reorganization that ultimately led to opening of the Scotia Sea. • Integrated sedimentology and palaeoecology of the Danian in Antarctica. • Stratigraphy and characterization of a wave-dominated, tidally influenced delta. • Impact of sedimentary regression on record of post-catastrophe biotic recovery. • Danian regression and mid-Paleocene inversion herald Scotia Sea opening. [ABSTRACT FROM AUTHOR]

The sedimentary rocks of the Paleocene Hangu Formation in the Yadgaar Section of the Upper Indus Basin in northern Pakistan, have been the subject of an integrated field, petrographical, and sedimentological investigation. The goals of this study are to improve our understanding of the sedimentary environment, facies shifts, and the impact of tectonism on the genesis of the investigated sedimentary facies. A better understanding of the intricate relationships between the aforementioned factors will clarify whether the regional tectonic drive has partial control over or complete command of the sedimentation processes. The results of this study shows that the Hangu Formation consists of four facies: bauxite, sandstone, coal, and limestone. The bauxite deposits formed in a karst environment with severe chemical weathering in a humid to extremely humid climatic setting. Thin coal laminae indicate a peatland environment that formed within a humid tropical climate. Sub-arkose, arenite, and arkose sandstone facies mark deltaic (sub-humid), coastal–near shore (humid to hot-humid), and high-energy fluvial (arid to semi-arid) sedimentary environments, respectively. Finally, the occurrence of marly limestone points towards deposition on a shallow marine carbonate platform within a coastal-brackish environment. The facies shift of the sediments provides evidence for a gradual transition from continental to marine conditions within the study area, together with episodic transgressive and regressive cycles as well as changing climatic and geomorphological conditions. In consequence, all these changes are controlled and shaped by the effects of Paleo-Tethys tectonism during the Indo-Eurasian intra-oceanic subduction. This advancement through the current work helps in understanding tectonic-sedimentary mechanics, i.e., how regional tectono-sedimentological processes influence the formation of sedimentary sequences. [Display omitted] • An integrated petrological and sedimentological study has been carried out on the Hangu Formation. • Lithofacies and microfacies approach used for the better understanding of the paleoclimate and sedimentary environment. • Insight of paleoclimate was implemented to reconfirm the sedimentary environment. • Integration of sedimentary environment, paleoclimate and facie shift is used to reconstruct the paleotectonic evolution. [ABSTRACT FROM AUTHOR]

The Paleocene-Eocene Thermal Maximum (PETM) was identified for the first time in two sections (Bongue and Dibamba) from the Douala sub-basin located in the Gulf of Guinea, Cameroon. This discovery was based on a multi-disciplinary approach including biostratigraphy and occurrence of benthic and planktic foraminifera and ostracods, major and trace element contents, mercury, organic carbon isotope (δ13C org values), total organic carbon (TOC), whole-rock and clay mineralogy. A combination of lithology, microfossil assemblage, and carbon isotope data indicate zone P5 and the top of the Paleocene enabling the definition of the Paleocene-Eocene boundary (PEB). A negative carbon-isotope excursion (CIE) spanning from the uppermost Paleocene deposits to the earliest Eocene sediments (PETM interval) shows a shift in δ13C org values of 1.5‰ in Bongue and 3.0‰ in Dibamba. In both sections, this interval is affected by widespread acidification, as revealed by carbonate dissolution and microfossil preservation (i.e., species are dwarfed, broken, thin shelled, and with holes). The very low carbonate content and the scarcity of microfauna indicate the severity of acidification during the PETM, especially in the early Eocene where only one species was identified (Igorina broedermanni). Mercury anomalies, TOC contents, and trace element concentration ratios, point to volcanic activity linked to the Cameroon Volcanic Line (CVL) intrusive magma, and a decrease in productivity prior to the PETM. In addition to climate change, our geochemical and mineralogical data support the hypothesis that other environmental perturbations such as an increase in productivity and detrital input, as well as a decrease in bottom water oxygenation occurred during the PETM in the Douala sub-basin. • The first to identify PETM in Cameroon, onshore part of Douala sedimentary sub-basin. • Latest Paleocene P5 zone, just below the PETM, revealed by microfossils assemblage. • Sustained severe ocean acidification correlates closely with the prominent CIE and major phase of faunal turnover. • Pre-PETM detrital supply conditions and ocean hydrographic change linked to the intrusive proximal volcanism, the present Cameroon Volcanic Line. • Major paleoclimate and sea level changes during the P-E transition. [ABSTRACT FROM AUTHOR]

This investigation combines a number of datasets to provide an enhanced and improved tectono-geomorphological framework with which to identify new possible structural lineaments in northwest Pakistan. The dataset includes satellite images and geographic information system (GIS) methods. The present study was carried out using the USGS ASTER DEM (30 m), Landsat 8 (OLI/TIRS) and surface field geology of the study area. Different band combinations, directional filters and principle component analysis (PCA) methods were used to identify the major structural styles and tectonic geomorphological pattern. The panchromatic band (Band-8) was applied to the Landsat 8 satellite images in order to increase the spatial resolution from 30 m to 15 m which aided in the investigation and comparative analysis of tectonic geomorphology and structural styles. Drainage patterns of Zindapir Anticline (ZA), Sakhi Sarwar (SS), Sulaiman Foredeep (SF) and Kingri Fault (KF) areas were generated using Strahler order of streams. The results suggested a combination of the dendritic network with a minor component of trellis pattern for ZP and SF areas, hence proposing a combined structural and stratigraphic/lithological control, whereas the KF area indicated an element of a rectangular pattern suggesting a more structural influence in the western part in comparison to the eastern region. The presence of water gaps (WaGs) and active drainage network indicate lateral growth and propagation directions of the ZP and SS frontal anticlines following the Paleocene Epoch. The geomorphic evidence coupled with satellite data show that the SFTB is tectonically active along with the adjacent SF. The stream courses are deflected or guided due to active folds and tectonics in the area characterized by the distinct fluvial erosional pattern on the flanks/limbs of ZA. Evidence from the study suggests that compressional deformation, uplift and erosion played a significant role in the shaping of the structural and depositional architecture of the basin. It is proposed that the deformation in the SFTB during the late Paleogene is related to the Indian-Eurasian oblique collision, while the subsequent late Tertiary collision of Indian Plate with the Afghan Block (an accreted part of southern Eurasia) further ensued compressive deformation. The results from this study elucidate the possible models proposed for this compressional regime with prevailing wrenching by presenting new data. The findings from this research reveal new tectono-geomorphological features and lineaments in the area that were not documented previously. • An improved insight into the tectonic geomorphology of fold-thrust belt and foredeep, NW Pakistan. • Advantage of using freely available datasets to better understand the active tectonics shaping the surface and drainage architecture. • The demarcation of a new set of structural lineaments is presented. • Both tectonics and erosion/sedimentation contributed to surface morphology. • Variable drainage patterns with structural influences and stratigraphic controls. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Cenozoic stress field sequences in the north Eastern Qinling Mt. are defined. • Cenozoic tectonic process in the north Eastern Qinling Mt. is rebuilt. • The tectonism is linked with the Pacific subduction and the Tibetan expansion. Abstract A series of NE and NW-trending Cenozoic faulted basins, located at the north margin of the Eastern Qinling Mountains, document Cenozoic intracontinental extension process in Central China. Based on fault kinematic analysis of the faulted basins, coupling with the stratigraphic sequence, we rebuilt a tectonic stress sequence of the faulted basins since the Cenozoic era. Combined with the previous chronological data, we define the Cenozoic faulted basin formation process including two stages of tectonic evolution. The first stage largely presents the NW-SE extensional rifting in a long period from the Paleocene to the Middle-Late Miocene due to northwestward subduction of the Pacific plate. It is marked by the basin occurrence along the north margin of the Eastern Qinling Mountains (e.g., the Sanmenxia, Lushi, Shangluo, and Weihe Basins) in the Paleocene to the Early-Middle Miocene in accordance with a NW-SE extension, and regional basin inversion in the Middle Miocene as the result of a NW-SE compression. The second stage is featured by the three-episode extension since the Middle-Late Miocene, which is probably affected by the combination of the northeastward growth of the Tibetan Plateau and the northwestward subduction of the Pacific Plate. The earliest episode of NW-SE extension caused by regional NE-SW compression in the Late Miocene to Early Pleistocene, which leads to the formation of the Yuncheng Basin. A gentle NE-SW extension subsequently dominated here in the Late Pleistocene, as represented by the widespread appearance of paleo-lakes in the basins. Then the youngest tectonic regime controlled this region, characteristic of a tectonic transpression (ENE-SWS compression and NNW-SSE extension), causing evidently strike-slip activities on the primary faults in the basins. [ABSTRACT FROM AUTHOR]

Abstract Back-arc basins and the related subduction systems have been extensively studied, however back-arc basins exhibiting episodic jumps of extension centers by the subduction of different ocean slabs are poorly known. The East China Sea Shelf Basin (ECSSB) comprises two eastward-younging subparallel depression zones, and its formation and evolution is accompanied by a complicated subduction history and regional tectonic events offer an excellent opportunity to decipher the various geological features of back-arc basins. Here, we review the tectonic and sedimentary features of the subbasins in the ECSSB and its adjacent regions and then reconstruct the evolution of the sedimentary paleogeography. The west depression zone (WDZ) of the ECSSB experienced rifting in the Late Cretaceous during the subduction of the Izanagi Plate at the eastern continental boundary. In the northern WDZ, the Changjiang Depression was mainly dominated by fluvial to lacustrine deposits. This depression experienced strong compression characterized by folds and erosion during the transition from a synrift to postrift setting at the end of the Paleocene. Then another compression event occurred that resulted in extensive folds and uplift accompanied by a large-scale alluvial fan in the eastern Changjiang Depression, coinciding with the subparallel subduction of the Izanagi-Pacific ridge in the early Eocene. However, the Lishui-Jiaojiang Sag characterized by diffuse extension rather than focused rifting in its late rifting period. This sag was mainly covered by paralic to marine deposits and experienced extensive erosion caused by tilted sequences from the late Eocene to Oligocene, which shared the same characteristics as basins around the Taiwan region. It is widely accepted that the formation and evolution of basins around Taiwan were controlled by the evolving of the South China Sea (SCS) and the related regional tectonics. Considering the eastward extent of SCS, it would seem that the southern ECSSB was part of the passive margin of SCS. Accordingly, the southern ECSSB might be significantly influenced by the SCS. The east depression zone (EDZ) commenced rifting in approximately the middle Eocene as inferred from the absence of the compressional event that occurred in the early Eocene and the existence of a thick layer reflection below the Pinghu Fm. (late Eocene) due to the subduction of the Pacific Plate. The depocenters of the ECSSB and the Okinawa Trough jumped eastward successively triggered by the three oceanic slabs of the Izanagi Plate at ~72 Ma, the Pacific Plate at ~50 Ma and the Philippine Sea Plate at ~15 Ma. Thus, a new model for the formation and evolution of the ECSSB is suggested in which a back-arc basin of episodic extension with jumping depocenters in respond to subduction of three oceanic slabs, meanwhile its differences between northern and southern part are caused by the dominant subduction and opening of SCS, respectively. The ECSSB and Okinawa Trough might formed mainly by rollback of the oceanic slab, possibly, due to slab stagnation and toroidal flow related to the subduction, however the effects of large-scale mantle flow cannot be exclusively identified in this research. In addition, further research in this region will give new insights into both the formation and evolution of the SCS and the continental breakup process. [ABSTRACT FROM AUTHOR]

Abstract Paleogeographic interpretations have been carried out in Lebanon by means of paleontological analysis. This study is complementary to previous records which have explained the paleogeographic setting of the western side of Lebanon during the Cenozoic. Extensive fieldwork and sampling were performed in the area of Zahle (west part of the Bekaa Valley). Samples collected from this locality provided diverse microfossil assemblages. The results show that there is a major change in the paleogeographic setting during the transitional period extending from early Eocene to Miocene. These changes in paleogeographic setting resulted from repeated episodes of emergence and submergence due to oscillating tectonic movements, leading to variations in the sedimentation patterns across the Bekaa Basin. The new findings of calcareous nannofossils in the chalky facies of Zahle area frame the paleogeographic settings during the Paleocene and early Eocene. Regression was clearly recognized during the early middle Eocene, which was revealed by the change in marine setting from the deep in the early Eocene (represented by the chalky facies), to the shallow settings in the middle Eocene where the nummulite banks were formed. This sedimentation pattern appears to coincide with major break in the sea level curve already reported by many researchers. During the Oligocene, the collision between the African-Arabian and Eurasian plates started causing further uplift of the Lebanese structures and consequent partial erosion (non-sedimentation) of the above-mentioned lithologies. The sedimentation pattern during the Miocene in Lebanon reveals a major change shifting from a primarily marine regime to fully lacustrine. Highlights • The calcareous nannofossils shed new light on the relative age their paleoenvironmental deposition. • Paleocene and Eocene samples represent the deep marine setting. • The analysis of the dynamic behavior of Nummulites provides evidences of the palaeoenvironment during that Eocene time. • The variety in sedimentation patterns and sea level fluctuation reflect different sub-basin architectures. [ABSTRACT FROM AUTHOR]

Graphic abstract Highlights • Taraklı Flysch sedimented in a foredeep during a continental collision. • The top of the Taraklı Flysch shows a "slide-blocks in shaly-matrix" lithofacies. • The top of the Taraklı Flysch is characterized by slide blocks of granitoids. • Permian age of granitoids is determined by U-Pb geochronology on zircon crystals. • The source area of the granitoids is identified in the Istanbul-Zonguldak margin. • The geodynamic setting of the Taraklı Flysch is reconstructed. Abstract In the Boyalı area (northern Anatolia), a thick succession of the Early Maastrichtian - Middle Paleocene Taraklı Flysch crops out. The Taraklı Flysch represents a foredeep sediment deposited during the final stage of collision between the Sakarya and Istanbul-Zonguldak continental margins, that developed as a consequence of the closure of the Intrapontide oceanic basin. The top of the Taraklı Flysch is characterized by a level of slide-block in shaly-matrix lithofacies that can be considered as the result of several fast catastrophic events predating the closure of the basin and its deformation. This level consists of slide-blocks surrounded by monomict pebbly-mudstones and pebbly-sandstones. Among the slide-blocks, the biggest one consists of quartz-monzonites and leucocratic granodiorites of Late Permian age (260.8 ± 2.2 Ma) dated by zircon LA-ICP-MS method. By comparison with the regional data, the source area of these granitoids can be identified in the Istanbul-Zonguldak terrane. This evidence suggests a new picture for the paleogeographic setting of the ultimate stage of the continental collision between the Istanbul-Zonguldak and the Sakarya continental margins. In this scenario the coarse-grained deposits of the Taraklı Flysch are supplied by an orogenic wedge, consisting of oceanic units topped by the Istanbul-Zonguldak terrane. This orogenic wedge represented the north side of the foredeep, while the southern one was represented by the still undeformed Sakarya continental margin. [ABSTRACT FROM AUTHOR]

Abstract The Selandian-Thanetian (S/Th) succession is extensively represented and well exposed along the eastern escarpments of the Kharga Oasis, Western Desert, encompasses the upper part of the Dakhla Formation, Tarawan Formation and the lower part of the Esna Formation. This study based on the qualitative and quantitative investigation of the planktonic and benthic foraminiferal assemblages aims to assess and specify the S/Th transition in terms of the biostratigraphic, paleoecologic and sequence stratigraphic analyses. The studied interval is subdivided into three 3rd order depositional sequences (Seq. 1, Seq. 2 and Seq. 3) separated by two sequence boundaries at the Dakhla/Tarawan (SB 1) and the Tarawan/Esna (SB 2) contacts, respectively. The S/Th boundary is placed at the Maximum Flooding Surface (MFS) of the second depositional sequence (Seq. 2) within the Tarawan Formation and lies at about 6 m above the base of a distinct thin layer related to the Mid-Paleocene Biotic Event (MPBE). The S/Th MFS is characterized by a relatively highest positive peak in the P/B ratio (90%) and the common occurrence of the bathyal benthic taxa. The reported MFS displays great correspondence with the eustatic sea-level related to the timing and extent that can be treated as a secondary criterion relevant for delineating and correlating the Selandian-Thanetian transition everywhere. Highlights • This work evaluates the Selandian-Thanetian transition. • The foraminiferal analyses are used to evaluate the paleoenvironmental conditions. • The studied interval is subdivided into three 3rd order depositional sequences. • The Selandian/Thanetian boundary is placed at the MFS of the second sequence. [ABSTRACT FROM AUTHOR]