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Herein, we present a diverse record of dinoflagellate cysts from the lignite-associated sedimentary succession (belonging to the Akli Formation) at Sonari Lignite Mine, Barmer Basin, Rajasthan State, western India. The dinoflagellate cyst assemblage implies a Danian to Ypresian age for the investigated succession and argues that the deposition of lignitic sequences along India's western margin is not coeval. We also identify two vertebrate (dominantly fish-yielding) units within the studied Akli Formation succession. The Ypresian fish genera (mainly represented by dental remains) include Ginglymostoma, Jaekelotodus, Brachycarcharias, Pycnodus and Myliobatis while the Selandian-Thanetian fish dental remains include Dasyatis. A discontinuous distribution of fish fauna during the early Paleogene (based on the temporal and spatial data) within the lignite-associated sedimentary successions of western and north India allows us to infer the prevalence of separated realms with variably restricted palaeoenvironmental conditions. Overall, the faunal evidence is indicative of dominantly estuarine to shallow marine conditions with enhanced freshwater influence during the Thanetian as compared to the Danian. Our study also argues in favour of the earliest appearance of dinoflagellate cyst Apectodinium in the near-equatorial region of the Tethys Ocean during the early Paleocene. (within Danian). [ABSTRACT FROM AUTHOR]

One new extinct species of the genus Atomaria Stephens, 1829 is described and illustrated: A. (Anchicera) telnovi sp. nov. from Rovno amber. It is the sixth species of the subgenus Anchicera in Eocene amber; two-thirds of all species and two-thirds of all reported Eocene amber silken fungus beetle specimens belong to this subgenus. The reasons for the relative abundance of Anchicera in the Eocene fossil resins are discussed. A key to extinct Eocene species of Atomaria is provided. [ABSTRACT FROM AUTHOR]

The Cenozoic stratigraphy of the Zagros records the ongoing collision between the Arabian and Eurasian Plates and the closure of NeoTethys. A Paleogene NW‐SE trending foreland basin was inherited from a Late Cretaceous precursor. Widespread progradation into the foredeep was a feature of both margins which, allied to ongoing tectonism, had by the late Eocene led to the narrowing and subsequent division of the foredeep into the Lurestan – Khuzestan and Lengeh Troughs, separated by the northward continuation of the rejuvenated Qatar‐Fars Arch. This sub‐division strongly influenced subsequent deposition and the petroleum geology of the area. In addition, the diachronous nature of the Arabian – Eurasian collision led to strong diachroneity in lithostratigraphic units along the length of the Zagros. Hence its petroleum geology is best understood within a regional sequence stratigraphic framework. This study identifies three tectono‐megasequences (TMS 10, TMS 11a, TMS 11b) and multiple depositional sequences. The Cenozoic contains a world class hydrocarbon province with prolific oil reservoirs in the Oligo‐Miocene Asmari Formation sealed by the evaporite‐dominated Gachsaran Formation, mostly contained within giant NW‐SE trending "whaleback" anticlines concentrated in the Dezful Embayment. Reservoirs in the SW are dominantly siliciclastic or comprise mixed siliciclastics and carbonates, whereas those to the east and NE are dominated by fractured carbonates. There remains untested potential in stratigraphic traps, especially in deeperwater sandstone reservoirs deposited along the SW margin of the foredeep. Late Miocene to Pliocene charge to the Asmari reservoirs was mostly from Aptian – Albian Kazhdumi Formation source rocks. In some fields, an additional component was from organic‐rich late Eocene to earliest Oligocene Pabdeh Formation source rocks confined to the narrowing Lurestan – Khuzestan Trough. Where mature, the latter source rock is also a potential unconventional reservoir target, although the prospective area is limited due to recent uplift and erosion. Deeper Jurassic source rocks contributed to the Cheshmeh Khush field in Dezful North. Silurian source rocks charged gas‐bearing structures in the Bandar Abbas region. [ABSTRACT FROM AUTHOR]

Boninites (BONs), high-Mg andesites (HMAs), and related lavas and dikes of Palaeogene ophiolites of the SW Pacific in Papua, New Guinea, New Caledonia, and the North Island, New Zealand, interpreted as having formed subsequent to forearc basalt (FAB) during subduction initiation (SI) are investigated to determine whether these are similar to second-stage lavas and dikes of other SI ophiolites and the IBM forearc. SW Pacific second-stage lavas and dikes are mostly high-Si BONs, but range to HMAs with the latter appearing to have preceded the formation of the former. Partial melting was due to flux-melting of a depleted source with the addition of hydrous and LREE-, Sr-, and Zr-enriched sediment melts to the mantle wedge subsequent to extraction of first-formed FAB. New Caledonia second-stage BONs are mostly consistent with ~5–15% partial melting of a source, which had undergone two previous melt extraction events and in New Zealand, second-stage HMA dikes are consistent as the result of 10–20% partial melting of a depleted source having undergone initial FAB extraction followed by a maximum of ~25% partial melting of a source produced subsequent to the first extraction event. Thermobarometry calculations of primitive second-stage BON and HMA lavas and dikes record potential temperatures generally similar to but pressures lower than MORB. Although most PUB ophiolite and both New Zealand HMA samples plot within the field of MORB with TP of about 1280–1350°C and pressures of ~0.8–1.80 GPa, all remaining second-stage BONs and HMA exhibit TP and pressures lower than MORB. A clear demarcation exists between New Caledonia BONs and PUB HMA, the latter of which records much higher TP and lower pressures than the former and range from ~1330 to 1420°C and from 0.7 to 1.40 GPa. These anomalously high temperatures for the PUB may infer a plume-induced SI event. [ABSTRACT FROM AUTHOR]

After about a century, the skull of the holotype and sole specimen of Arambourgia gaudryi from the Eocene of Quercy (France) is here redescribed. Its interest resides in its extreme morphology, such as its very small skull and altirostral condition, that raises questions about its maturity, taxonomic validity, and paleoecology. In order to reveal previously hidden anatomical details, we used computed microtomography (µCT-scan) data to digitally extract the bones of the cranium and mandible, as well as the endocranial structures. Here, we update the osteological description of A. gaudryi, outlining new characters and re-evaluating anatomical details. Comparing it with ontogenetic series of extant crocodylians, we confirm that the specimen is a mature individual of a dwarf species with pedomorphic features. Our phylogenetic analyses indicate that A. gaudryi is an alligatorine. Comparisons with other small alligatoroid taxa show that it is indeed a valid species. The depositional environment of the finding site suggests a continental context with a karstic network. Taking this into account, together with its peculiar anatomy, we propose that A. gaudryi was a semi-terrestrial animal occupying an ecological niche similar to that of extant juvenile or dwarf crocodylians. Finally, we discuss the current knowledge of the paleobiogeography of Alligatoroidea in Europe during the Paleogene. Arambourgia gaudryi was likely part of a group of small early globidontans that arrived in the Old World, probably from North America, around the end of the Paleocene and that dispersed to at least four localities of the ancient European archipelago. [ABSTRACT FROM AUTHOR]

The Paleocene deposits from the Cerrejón Formation (Colombia, South America) have provided abundant snake remains. All this material has been assigned to the giant snake Titanoboa cerrejonensis. Here, we describe six vertebrae from among the referred materials that do not correspond to Titanoboa. All six vertebrae are morphologically identical, of a similar size, and display a distinct morphology that differs from Titanoboa. This new and unnamed taxon is a large snake estimated to be around eight meters in total length. Anatomical comparisons show that these vertebrae possess certain features typical of the Palaeophiidae, a group of extinct snakes of uncertain relationships known almost exclusively from vertebrae. Among the Palaeophiidae, the new taxon resembles the more generalized forms assigned to the genus Palaeophis, but lacks the extreme aquatic adaptations that define forms assigned to the genus Pterosphenus. We regard the new taxon as an undetermined palaeophiine but do not assign it to Palaeophis as a number of features differ from that described genus. This new record expands the known diversity of aquatic snakes from the Paleogene of South America and provides a substantial new record for the paleogeographic distribution of the Palaeophiidae. The oldest records are from the Cretaceous of Africa, while Paleocene records are poorly known and restricted to Africa, North America, and Europe. The majority of vertebral forms assigned to Palaeophiidae are from the Eocene, principally from the Tethys region, with only one previous South American record coming from the Eocene of Ecuador. [ABSTRACT FROM AUTHOR]

Timing is a key data for understanding the origin of faulting. The Balcones fault system (BFS) extends ~600 km along the northern margin of the Gulf of Mexico oil basin and controls springs that supply the major cities in Texas, but its origin is unclear. We provide its first direct timing by applying U–Pb geochronology on seven calcite‐mineralized fault surfaces. We have found that this extensional fault system formed during the Palaeocene‐middle Eocene time (from 61.3 ± 2.7 to 45.4 ± 2.1 Ma), which is much earlier than previous estimates. We show that the formation of the BFS coincides with the largest clastic influx in the northern Gulf of Mexico basin that resulted from Laramide uplift and erosion. This timing and the location of the BFS along the Ouachita suture, support our interpretation of this fault system formed as the result of lithospheric flexure related to Paleogene sedimentary loading. [ABSTRACT FROM AUTHOR]

Sharks are virtually absent from coastal Antarctica since the Late Eocene glaciations, but this group exhibited a notable austral diversity during the Cretaceous and Paleogene. Several species have already been described from the Aptian-Eocene successions of the Larsen Basin exposed in the James Ross Island area (northern Antarctic Peninsula) and the predominantly deep-water Hexanchiformes have a record that, although still rare, has been continually increased. Four species of this group are currently known from that basin: Notidanodon pectinatus, Xampylodon dentatus, Rolfodon thompsoni, and Rolfodon tatere. Such records are especially concentrated in the Gamma Member of the Snow Hill Island Formation (or Herbert Sound Member of Santa Marta Formation), on James Ross Island. Here we described four teeth assigned to X. dentatus and one identified as R. tatere from upper Campanian sections of James Ross Island, highlighting the nomenclatural changes that led to the definition of Xampylodon and Rolfodon. Some specimens of X. dentatus presented here are considerably more complete or represent teeth of different positions than most previous records. The material assigned to R. tatere represents the oldest record of this species in the world, extending its time range by more than 10 million years. [ABSTRACT FROM AUTHOR]

Ray-finned fishes, which compose nearly half of living vertebrate diversity, provide an excellent system for studying the evolution of novel body forms. Lampriformes is a species-poor lineage of acanthomorph ray-finned fishes that has evolved two very different and highly specialized body plans suited to life in pelagic oceanic habitats: the deep, round-bodied bathysomes and the ribbon-like taeniosomes. Here, we present a new phylogenetic hypothesis and divergence time estimates for lampriform fishes based on an updated morphological dataset and DNA sequences from nuclear genes for all but one of the living lampriform families and 55% of recognized extant genera. Our analyses resolve two major clades in Lampriformes: the Bathysomi and the Taeniosomi. A time calibrated phylogeny shows that the origin of living lampriforms coincides with the aftermath of the Cretaceous–Palaeogene extinction and that anatomically modern pelagic morphotypes evolved 10 Myr after the start of the Palaeogene. [ABSTRACT FROM AUTHOR]

The quantitative estimation of key parameters of paleotemperature and paleoprecipitation is crucial for paleoclimate reconstruction. Geochemical data from modern sediments are highly consistent with climate data, and their relationship can provide an important reference for the quantitative reconstruction of the paleoclimate. In this study, detailed inorganic geochemical analysis was carried out using high-precision sampling of the Paleogene (LFD-1 well) Guchengzi, Jijuntun and Xiloutian Formations in the Fushun Basin located in the mid-latitudes of the Northern Hemisphere. The Eocene Guchengzi Formation (54.51–47.8 Ma) and Jijuntun Formation (47.8–41.2 Ma) in the Fushun Basin were found to have been deposited under a humid climate. The lower (41.2–40.1 Ma) and upper (40.1–37.8 Ma) parts of the Xiloutian Formation were characterized by semiarid and semihumid–semiarid climates, respectively, which is very similar to the paleoclimatic information reflected by organic carbon isotopes. The Eocene Thermal Maximum 2 (ETM2, ~ 53.7 Ma), Early Eocene Climatic Optimum (EECO, ~ 53.1–46.5 Ma, Eocene Thermal Maximum 3 (ETM 3, ~ 52.8 Ma), and Middle Eocene Climatic Optimum (MECO, ~ 40.7–40.1 Ma) events significantly enhanced chemical weathering during these periods. The rapid increase in pCO2 concentration leads to an increase in temperature, precipitation, and surface runoff, exhibiting strong chemical weathering. The mean annual temperature (MATa) and mean annual precipitation (MAPa, MAPb, and MAPc) were estimated using parameters, such as the corrosion index without potassium (CIA-K), CaO/Al2O3, and (Na2O + K2O)/Al2O3. Comparing MAPa, MAPb, and MAPc with the MAP estimated using pollen data, MAPa and MAPb were found to be more sensitive to the climate during high precipitation periods (precipitation > 1000 mm, Guchengzi Formation), and the recovered average precipitation was similar to MAP. In contrast, MAPc was more sensitive to the climate during low precipitation periods (precipitation < 1000 mm, Jijuntun, and Xiloutian Formations), with higher accuracy. To fully consider the influence of soluble inorganic salts Ca2+ and Na+, multivariate linear equations of CIA-K and CaO/Al2O3 with CIA, and CIA-K and CaO/Al2O3 with MAP were constructed, namely MAPd and MAPe. The results show that MAPe has the highest performance and can be effectively used to estimate the change of paleoprecipitation in Northeast Asia. [ABSTRACT FROM AUTHOR]

The U–Pb detrital zircon record of the Surat Basin, an important part of the Great Australian Superbasin, has already revealed important insights about sediment source terranes. However, owing to the high closure temperature of zircons, low-temperature thermal events that might have impacted the sediment are not recorded. Here, new 40Ar/39Ar detrital mica ages, which record low-temperature events as a result of isotopic resetting, are paired with published U–Pb detrital zircon ages from the same samples to provide a more complete interpretation of the tectonic and thermal history of the Jurassic-age Precipice Sandstone and Evergreen Formation. The 40Ar/39Ar geochronology of mica grains from five wells reveals two broad groups with distinct age populations: 1500–180 Ma and 150–45 Ma. Micas older than about 180 Ma are sourced from multiple terranes. The slight discrepancy in ages between the 40Ar/39Ar and the U–Pb systems of the same samples may represent differences in closure temperature. However, some micas, such as those dating to ca 180 Ma, may also reflect a thermal reset event. Similarly, the younger group of micas, split into Cretaceous and Paleogene populations, reflect the impact of post-depositional thermal events on the basin. Isotopic resetting of the micas was likely the result of hydrothermal fluids migrating through reactivated faults, fractures and/or porous and permeable sediments. The origin of the fluids during the Cretaceous can be linked to an eastern subduction zone and subsequent igneous underplating resulting in uplift and denudation. The exact source of the hydrothermal fluids for the micas of Paleogene age, recorded in samples collected from the base of the Evergreen Formation, however, remains uncertain. Importantly, 40Ar/39Ar dating of mica from sandstones permits the detection of post-depositional thermal events that may have implications for tracing fluid migration throughout the basin and reconstructing the Cretaceous–Paleogene tectonic history of the basin. Combining 40Ar/39Ar dating of micas with U–Pb dating of zircons reveals a more complete tectonic and thermal history of the Jurassic-age Precipice Sandstone and Evergreen Formation of the Surat Basin. 40Ar/39Ar dating of detrital micas reveals two broad groups with distinct age populations: 1500–180 Ma and 140–45 Ma. Ages older than ca 180 Ma are linked to multiple source terranes, including the Thomson and New England orogens, and the contemptuous magmatic arc. Ages younger than 150 Ma are most likely the result of post-depositional thermal resetting events, which may have implications for fluid movement throughout the basin. [ABSTRACT FROM AUTHOR]

Observations show that mesospheric clouds (MCs) have been increasing in recent decades, presumably due to increased mesospheric water vapor which is mainly caused by greater methane (CH4) oxidation in the middle atmosphere. Past warm climates such as those of the early Cretaceous and Paleogene periods are thought to have had higher CH4 concentrations than present day, and future CH4 concentrations will also likely continue to rise. Here, idealized atmosphere chemistry‐climate model experiments forced with strong polar‐amplified sea‐surface temperatures and elevated carbon dioxide (CO2) and CH4 concentrations predict a substantial spreading of MCs to middle and low latitudes, well beyond regions where they are currently found. Sensitivity tests show that increased water vapor from CH4 oxidation and cooling from increased CO2 and CH4 concentrations create favorable conditions for cloud formation, producing MC fractions of 0.02 in the low latitudes and 0.1 in the mid‐latitudes in the Northern Hemisphere when CH4 concentration is 16× higher than pre‐industrial. Further increases in CH4 result in a monotonic increase in low‐ and mid‐latitude MCs. A uniform surface ocean warming, changes in polar amplification, or the solar constant do not significantly affect our results. While the appearance of these clouds is interesting, their ice and liquid water content is not sufficient to cause a significant radiative effect. On the other hand, dehydration of the mesosphere due to these low‐ and mid‐latitude MCs could potentially lead to a reduction in atomic hydrogen, thereby affecting mesospheric ozone concentration, although further study is required to confirm this. [ABSTRACT FROM AUTHOR]

The Antarctic Digital Magnetic Anomaly Project is an international research effort to construct a magnetic map of the continent based on ground, satellite, marine, and aeromagnetic surveys. This paper reports the magnetic mapping of the shelf zone in the SE part of the Wilhelm Archipelago, West Antarctica, based on magnetic surveys conducted with Zodiac boats. A spectacular feature of this area is the strong magnetic anomaly of the Antarctic Peninsula (AP) batholith, which was the product of subduction-related Mesozoic–Cenozoic arc magmatism on the former margin of Western Gondwana. We constructed and analyzed a detailed magnetic map of magnetic field anomalies using field observations of rock exposures on the islands and magnetic properties of rocks from laboratory data. The oldest volcanic rocks of Jurassic to Lower Cretaceous age relate to N-NE trending bands of negative magnetic field. The largest feature in the study area is an Upper Cretaceous/Paleogene granodiorite complex that produces a positive magnetic anomaly. Many smaller anomalies are also present over gabbroid bodies of Cretaceous age. Two-dimensional magnetic modeling shows that heterogeneities in the upper crust may have magnetic susceptibilities in the range of 0.005–0.13 SI. Magnetic field anomalies also delineate an orthogonal system of tectonic faults, including the main NE fault along the Penola Strait (sub-parallel to the AP coastline) and four intersecting faults. These fault systems may be associated with different stages of continental margin evolution along the Antarctic Peninsula. [ABSTRACT FROM AUTHOR]

The shape of the ocean floor (bathymetry) and the overlaying sediments provide the largest carbon sink throughout Earth's history, supporting ~one to two orders of magnitude more carbon storage than the oceans and atmosphere combined. While accumulation and erosion of these sediments are bathymetry dependent (e.g., due to pressure, temperature, salinity, ion concentration, and available productivity), no systemic study has quantified how global and basin scale bathymetry, controlled by the evolution of tectonics and mantle convection, affects the long-term carbon cycle. We reconstruct bathymetry spanning the last 80 Myr to describe steady-state changes in ocean chemistry within the Earth system model LOSCAR. We find that both bathymetry reconstructions and representative synthetic tests show that ocean alkalinity, calcite saturation state, and the carbonate compensation depth (CCD) are strongly dependent on changes in shallow bathymetry (ocean floor =600 m) and on the distribution of the deep marine regions (>1,000 m). Limiting Cenozoic evolution to bathymetry alone leads to predicted CCD variations spanning 500 m, 33 to 50% of the total observed variations in the paleoproxy records. Our results suggest that neglecting bathymetric changes leads to significant misattribution to uncertain carbon cycle parameters (e.g., atmospheric CO2 and water column temperature) and processes (e.g., biological pump efficiency and silicate-carbonate riverine flux). To illustrate this point, we use our updated bathymetry for an Early Paleogene C cycle case study. We obtain carbonate riverine flux estimates that suggest a reversal of the weathering trend with respect to present-day, contrasting with previous studies, but consistent with proxy records and tectonic reconstructions. [ABSTRACT FROM AUTHOR]

We describe new macro- and microfossils recovered on a field expedition to the North Quarry of Poponguine, a locality in western Senegal that spans the Late Cretaceous through the Early Paleogene, albeit with a likely unconformity at the base of the Danian. Newly discovered macrovertebrates from the Maastrichtian Cap de Naze Formation include pycnodonts, dyrosaurids, and chelonians, the latter two the oldest and first Cretaceous representatives of these clades from Senegal. Screenwashing of this deposit revealed that the matrix also consists of abundant microscopic biological clasts comprising osteichthyan vertebrae, spines, and cranial fragments, shark dermal denticles, invertebrates, and numerous ovoid coprolites among other fragments. These microfossils document a much less conspicuous portion of the paleobiodiversity. We describe the stratigraphy of this new locality and incorporate it into a new correlated section that ties together three other Late Cretaceous–Early Paleogene fossiliferous localities of the Senegalese-Mauritanian Basin. The presence of fossiliferous Danian rocks, which are notably rare in West Africa, is elucidated in our section, which synthesizes prior geological and paleontological work around Poponguine and in the nearby coastal region of Ndayane. Primarily dated using the biostratigraphy of ostracods and foraminiferans, the correlated rock units include the Paki and the Cap de Naze Formations of the Late Cretaceous Diass Group and the Ndayane and the Poponguine Formations of the Paleocene Cap-Vert Group, deposits that capture ancient near shore marine environments. The localities described, although separated by only a few kilometers, exhibit dramatic differences in thickness across faulted blocks of the Diass Horst. Dyrosaurids, which are common fossils in nearshore marine outcrops of West Africa, have been hypothesized to be of African origin and to have dispersed to South America in the Late Cretaceous. This dyrosaurid specimen, although fragmentary, documents a western extreme in the geographic range of African dyrosaurids where the clade would have been well situated for broader trans-Atlantic dispersal. [ABSTRACT FROM AUTHOR]

Fossil scales from gar fish are made of bioapatite and are common in the continental sedimentary record from the Cretaceous to the present, prompting interest in using these fossil scales as geochemical archives. We investigated the diagenetic characteristics of the two different components of gar scales: ganoine, which has similarities to tooth enamel, and bone. We examined microscopic textural characteristics, spatially resolved trace element patterns, and apparent gar scale ages using the (U-Th)/He and U-Th-Pb systems, in modern scales as well as fossil scales from Cretaceous to Paleogene age strata in the North American Williston and San Juan Basins. Structural and textural characteristics of modern and fossil gar scales suggest that ganoine is more resistant to diagenetic alteration than bone. Trace element concentrations in fossil bone are at least an order of magnitude higher than in ganoine and can be spatially heterogeneous, indicative of a complex and prolonged diagenetic history. Trace element concentrations in fossil ganoine often decrease systematically with distance from the ganoine surface, which may be consistent with a fossilization model in which trace element concentrations are controlled by an inwardly propagating recrystallization front. However, (U-Th)/He dates of ganoine are substantially younger than expected based on basin thermal histories and compared to conventional detrital apatite (U-Th)/He dates from the same localities. The ganoine (U-Th)/He dates are also older than a few Ma for only the lowest effective uranium concentrations. We interpret the young (U-Th)/He dates and the date-effective uranium pattern to be indicative of either protracted or late-stage incorporation of trace elements, which is inconsistent with a recrystallization front model alone. The young (U-Th)/He dates may also reflect microstructurally-controlled low helium retentivity in gar scale ganoine, although this does not explain the observed date- effective uranium systematics. Late-stage incorporation of trace elements is supported by the U-Th-Pb systematics of ganoine, which require addition of U and Th at a time significantly later than the depositional age. Late-stage, or protracted, diagenetic uptake of parent nuclides in gar scale ganoine contrasts with recent studies of bioapatite from conodont elements, which instead appear to exhibit late-stage parent nuclide loss. We conclude that the (U-Th)/He system in gar scale bioapatite is not currently useful as a chronometer and suggest that applications of other trace element proxies to gar scale bioapatite be approached with caution. [ABSTRACT FROM AUTHOR]

The composition of the sub-arc mantle and the mode and nature of geodynamic processes during the India-Asia collision that controlled the melt evolution beneath the Gangdese belt (southern Tibet) are still unclear. Here, we present new U-Pb ages and Hf isotopes of zircon, and whole-rock geochemical and Sr-Nd-Pb isotopic data of the Paleocene-Eocene Najinla gabbros from the East Gangdese magmatic belt, aiming to track the transitioning magmatism formed from oceanic subduction to continental collision in the region. Zircon U-Pb analyses of these mafic rocks yield emplacement ages of 54 ± 1 Ma and 63 ± 1 Ma. The gabbros are characterized by variable SiO2 (45.87-55.44 wt%), MgO (1.03-8.18 wt%), FeOT (3.74-12.33 wt%), and Al2O3 (13.45-25.45 wt%) contents. Most samples exhibit high Al2O3 (17.15-25.45 wt%) and relatively low MgO (1.03-6.11 wt%), similar to typical high-alumina basalts and high-alumina basaltic andesites. The Najinla gabbros show characteristic subduction-related signatures with enriched large-ion lithophile elements and depleted high field strength elements. They have depleted Sr-Nd isotopic compositions with low and relatively homogeneous initial 87Sr/86Sr isotopic ratios of 0.7045-0.7049 and positive εNd(t) ratios of +2.2 to +3.2. The Najinla gabbroic rocks also have positive zircon εHf(t) values, ranging from +5.6 to +10.9. These results collectively suggest that magmas of the gabbros formed by partial melting of the asthenosphere with negligible crustal contamination during their emplacement. We propose that the mantle source of the Najinla gabbros was strongly influenced and metasomatized by subducted Neotethyan oceanic crust-derived fluids in the mantle wedge. Rollback of the subducted Neotethyan slab in the early Eocene led to partial melting of the subduction-modified mantle and the formation of these gabbros. [ABSTRACT FROM AUTHOR]

Data collated from subalkaline lavas and dikes of Palaeogene ophiolites of the SW Pacific in Papua, New Guinea, New Caledonia, and the North Island, New Zealand interpreted as having formed first upon subduction initiation, are investigated to determine whether these are MORB like, similar to other subduction initiation ophiolites and the IBM forearc. SW Pacific ophiolite subalkaline lavas and dikes are mostly tholeiitic basalt; however, calc-alkaline lavas comprise ~ 25% of New Zealand samples. Major element abundances of first-formed subalkaline lavas and dikes of SW Pacific ophiolites are broadly similar to MORB, however incompatible element abundances range from MORB-like to more depleted than MORB and similar to the most enriched IBM forearc basalt (FAB). The reason for the more enriched incompatible-element nature of first-formed lavas and dikes of SW Pacific ophiolites relative to the IBM FAB may be that the sources of the former, unlike the latter, based on recent studies were not subjected to a pre-subduction initiation melt extraction event. Partial melting estimates for first-formed lavas and dikes of SW Pacific ophiolites range from 12–23% of an initial MORB-like source to a maximum of 18% partial melting of this source after 20% melt extraction. Partial melting was due to decompression of a MORB-like source that received little to no slab-derived contributions. Thermobarometry calculations of primitive lavas and dikes with ≥ 8 wt.% MgO and Mg# ≥ 60 show that the mantle source of SW Pacific ophiolites records potential temperatures and pressures of 1341–1431°C and 1.1–1.8 GPa, similar to primitive MORB. These temperatures are at least 30–70°C lower than those required for Central American and IBM first-formed lavas supporting previous studies suggesting a plume-induced subduction initiation origin for Central America and the IBM. [ABSTRACT FROM AUTHOR]

The paleovegetation and paleoclimate characteristics are studied in the Palaeogene strata of Hetao Basin, Subei Basin and Qaidam Basin in China, and the Cretaceous Guyang Formation (K1g) in the Hetao Basin. These three basins receive high attention, different distribution areas, representative. Pollen evidence shows that: (1) The sporopollen assemblage of Palaeogene Linhe Formation (E3l) in Hetao Basin is characterised by Pinaceae-Ephedripites-Ulmipollenites-Chenopodipollis. It reflects that the ancient vegetation types were mainly coniferous and evergreen woody plants, and the climate was cold temperature. The sporopollen assemblage characteristics of the upper member of the Palaeogene Xiaganchaigou Formation (E32) in the Qaidam Basin are similar to it. (2) The sporopollen characteristics of the K1g in the Hetao Basin reflect that its ancient vegetation was dominated by evergreen woody plants and belongs to a warm and humid subtropical climate. (3) The assemblage of Palaeocene Funing Formation (E1f) in Subei Basin was Pterisisporites undulatus-Ulmipollenites minor-Taxodiaceaepollenites hiatus. The climate type was humid north temperate climate, vegetation was mainly deciduous trees and evergreen woody plants. (4) Leiosphaeridia/Granodiscus, Pediastrum and Botryococcus were also detected in the E1f of Subei Basin. The appearance of these algae indicates the special saline water environment and good hydrocarbon potential. [ABSTRACT FROM AUTHOR]

The early Eocene fossil assemblage of the London Clay (Southeastern England) is a key window to the early Paleogene diversification of teleost fishes in the open ocean. Despite their three-dimensional preservation that offers unique insight into skeletal anatomy, the London Clay fossils are still poorly described for the most part. †Whitephippus tamensis is a fossil teleost from this assemblage, known by several well-preserved specimens. Based on a complete description of the known material, including previously hidden structures (braincase, hyoid, and branchial arches) revealed through 3D microtomography, we reinterpret †Whitephippus as an early member of the teleost group Lampriformes. More specifically, the anatomy of †Whitephippus indicates that it is likely a member of the so-called 'pelagic clade' including modern opahs and oarfishes. This redescription of †Whitephippus provides the earliest definitive evidence of lampriforms conquering the pelagic environment, alongside numerous other teleost lineages. [ABSTRACT FROM AUTHOR]

The kinematics and deformation pattern along the Altyn Tagh fault (ATF), one of the largest strike‐slip faults on Earth is of great significance for understanding the growth of the Tibetan Plateau. However, the initial rupture along the ATF remains debated given the limited constraints on the depositional age of associated Cenozoic syntectonic strata. Here we investigated the syntectonic Cenozoic strata in the Xorkol Basin, associated with the strike‐slip faulting along the ATF. New uranium‐lead analyses of the carbonate deposits in the Paleogene strata yield dates of 58.9 ± 1.29 Ma, representing the initial rupture of the ATF. This first documented radioisotopic age coincides with the ca. 60 Ma onset timing of India‐Asia collision, highlighting its far‐field effect at the northern edge of the Tibetan Plateau. We infer that the deformation of the entire Tibetan Plateau started synchronously with the India‐Asia collision. Plain Language Summary: Carbonate U‐Pb dating techniques applied to rocks associated with the Altyn Tagh fault, a major fault in North Tibet, reveal that the fault started slipping about 58.9 million years ago, coinciding with the time when India collided with Asia. This finding provides new constraints on when and where this fault formed and suggests that the northern Tibetan Plateau started deformation earlier than previously thought. This result emphasizes that the entire Tibetan Plateau deformed simultaneously in the early Cenozoic. Key Points: Calcite U‐Pb dating yields ca. 59 Ma age for carbonate strata in the East Xorkol BasinXorkol Basin was a pull‐apart basin during the Paleocene due to the left‐lateral strike‐slip faulting along the Altyn Tagh faultWidespread Paleocene‐Eocene tectonism in Northern Tibet highlights the far‐field effect of the India‐Asia collision [ABSTRACT FROM AUTHOR]

The Arabia – Eurasia collision zone in the central part of the Alpine – Himalayan orogenic system has had a complex deformation history since the Palaeozoic. In Iran, the collision zone consists of the Alborz‐Talesh, Kopeh Dagh and Zagros foldbelts and the intervening Central Iran area. In this review paper, we summarize the structural architecture and tectonostratigraphic characteristics of these domains and attempt to correlate regional deformation events between them. The results show that six regional‐scale deformation phases can be recognized and correlated in Iran over a time interval extending from the Late Palaeozoic to the Late Cenozoic. Late Palaeozoic rifting in northern Gondwana and subsequent oceanic spreading resulted in the separation of the Central and North Iran blocks from the Arabian Platform. These blocks later converged and collided with the southern margin of Eurasia due to the subduction of the intervening PalaeoTethys lithosphere ("Cimmerian orogeny": Late Triassic). The convergent setting resulted in the initial development of the Alborz‐Talesh foldbelt in present‐day northern Iran, while extensional basins developed in the forebulge area in Central Iran. Continuing northward subduction of NeoTethyan oceanic lithosphere at the southern Eurasia margin produced Early Cretaceous back‐arc extension and associated volcanism in Central Iran and the Alborz‐Talesh area to the north. A phase of compressional deformation in the Late Cretaceous was related to the collision of a series of microcontinents derived from Northern Gondwana, including the Ercinjan and Bitlis massifs, with the Central Iran block, and is recorded in the Alborz‐Talesh foldbelt and in Central Iran. Further back‐arc extension in the late Paleocene – Eocene was accompanied by pervasive volcanism and volcaniclastic sedimentation throughout northern and Central Iran. The final closure of NeoTethys and convergence between the Arabian and Eurasian Plates evolved through phases of early Oligocene "soft" collision and middle Miocene "hard" collision. This was accompanied by thrusting in the internal parts of the Zagros foldbelt and by folding and subordinate thrusting in the more external parts, with related development of the flexural Mesopotamian Basin in the foreland to the SW. [ABSTRACT FROM AUTHOR]

Geophysical exploration of bauxite deposits has been carried out in the area of Posušje in Bosnia and Herzegovina, which were formed on an Upper Cretaceous carbonate substrate, whereas the hanging wall rocks can be Paleogene limestones and sedimentary clastic rocks. Karst terrains are demanding for geophysical exploration due to the relatively complex geological relationships and exceptional near-surface inhomogeneities that generate large noises and challenging conditions for taking field measurements. The fundamental question is whether geophysical research can detect exceptionally irregular karst bauxite deposits with relatively small dimensions. The basic idea is to combine several geophysical methods and a joint interpretation of several data sets to increase the efficiency of geophysical surveying in detecting complex bauxite deposits in karst terrains. Therefore, fundamental near-surface research methods, electrical tomography and seismic refraction are used. In addition, magnetometry was used to examine whether bauxite deposits yield potential magnetic anomalies that could help in detecting them. Research undertaken in the area of Posušje was carried out in the first step on already discovered and known bauxite deposits to determine whether geophysical responses correlate with the occurrence of bauxite deposits and to evaluate the effectiveness of each of the applied surface geophysical methods. Measurements were taken at several locations, and results for two micro-locations, Krstače and Mratnjača, are shown. Geophysical measurements were firstly performed on discovered bauxite deposits in order to reliably determine the possibility of identifying deposits in geophysical inverse models. Bauxite deposits were clearly recognised as characteristic geophysical responses in inversion models using both methods, electrical tomography and seismic refraction. Although the response of bauxite deposits is expressed in both models, resistivity and velocity, it is much more evident in resistivity models. The characteristic resistivity response was confirmed by the discovery of a new deposit. Therefore, the conclusion is that electrical resistivity tomography should be considered a basic method for exploring karst bauxite deposits. Seismic refraction provides a better characterisation of deposits and reduces the interpretation ambiguity. This solution can generally be applied to the problem of researching bauxite deposits in the Dinarides and similar geological models in the Mediterranean. Magnetometric measurements have shown that no magnetic anomalies could be associated with bauxite deposits, and only magnetometry was not successful in discovering bauxite deposits. [ABSTRACT FROM AUTHOR]

There are controversies about the climate evolution and driving mechanism around the Tibetan Plateau since the late Cenozoic. To better understand this issue, the Ningnan Basin on the north‐eastern margin of the Tibetan Plateau was taken as the research object. The Ningnan Basin was arid at 23–18 Ma under the influence of global climate change. The extensive deformation indicates that the uplift of the Tibetan Plateau and intracontinental pushing has influenced the Ningnan Basin and the paleoclimate began to be affected in 23 Ma. During the period of 17–13 Ma, the Ningnan Basin was warm and humid and was still under the influence of global climate change. During 8.5–8 Ma, the environment suddenly became dry. At the same time, the Tibetan Plateau was intensely uplifted, which strengthened the winter winds and weakened the summer winds, resulting in the aridity of the Ningnan Basin. [ABSTRACT FROM AUTHOR]

The Paleogene is a crucial period when terrestrial and marine ecosystems recovered from major disruptions and gradually approached their modern states. In the Qinghai-Tibetan Plateau and its surrounding regions, the Paleogene also represents a significant phase of tectonic evolution in the Qinghai-Tibetan Plateau-Himalaya orogeny, reorganization of Asian climates, and evolution of biodiversity. Due to limitations in research conditions and understanding, there are still many controversies regarding stratigraphic divisions in the Qinghai-Tibetan Plateau and its surrounding regions In recent years, extensive studies on sedimentary petrology, magnetostratigraphy, and isotope dating have been conducted in the region. Numerous fossils have been discovered and reported, contributing to a more systematic understanding of biostratigraphy. These studies have laid a solid foundation for the comprehensive investigation of the stratigraphy, biotas and paleogeographic evolution of the Qinghai-Tibetan Plateau and its surrounding regions during the Paleogene. In this paper, we integrate recent research on fossils, isotopic dating, magnetostratigraphy, and geochemistry to refine the stratigraphic divisions and correlation framework of different tectonic units in the region, building upon previous studies. Since the Second Tibetan Plateau Scientific Expedition and Research, the knowledge of Paleogene floras has gradually expanded. This paper discusses the biostratigraphic significance of extinct and newly appeared taxa based on the latest dating results of these plant species. The new understanding of fossil species such as the "Eucalyptus" and Arecaceae establishes connections between the Paleogene flora of the Qinghai-Tibetan region and the biotas of Gondwana, specifically Oceania and South America. The evolutionary history of key taxa near the Yarlung Zangbo suture zone indicates that the collision between the Indian and Eurasian plates occurred approximately 65–54 Ma. Paleoelevation reconstructions, based on plant fossils, suggest that the Hengduan Mountain had already formed their current topographic pattern prior to the Early Oligocene. The warm and humid lowlands adjacent to the main suture zones in the Paleogene Qinghai-Tibetan Plateau served as the primary pathway for biota exchanges. The relatively low elevation of the Himalaya during the Paleogene did not effectively block the moisture from the Indian Ocean. [ABSTRACT FROM AUTHOR]

Middle Eocene to early Oligocene intrusions, widespread in the Ruby Mountains– East Humboldt Range metamorphic core complex, Nevada, USA, provide insights into a major Paleogene magmatic episode and its relation to tectonism in the northeastern Great Basin. These intrusions, well-exposed in upper Lamoille Canyon, range in composition from gabbro to leucomonzogranite. They form small plutons, sheets, and dikes that intrude the metamorphic and granitic infrastructure of the core complex. Two types of Paleogene monzogranite were recognized. The first is exemplified by two of the larger intrusive bodies, the Snow Lake Peak and Castle Lake intrusions, which occur as sheet- like bodies near and at the structural base of metamorphosed Neoproterozoic and Cambrian Prospect Mountain Quartzite where it is inverted above Cambrian and Ordovician marble of Verdi Peak in the Lamoille Canyon nappe. Swarms of dikes are associated with these intrusions. U-Pb (zircon) ages range ca. 40– 33 Ma and typically display relatively simple and minor inheritance. The rocks have the lowest εHf (zircon) and εNd (whole rock) of any of the middle Cenozoic granites. The second type of monzogranite, Overlook type, typically occurs as thin, isolated dikes and leucosome- like bodies in Late Cretaceous granites of the infrastructure, with no obvious relationship to the large monzogranite bodies. Overlook- type monzogranite displays complex zircon inheritance, yields igneous ages ca. 37– 32 Ma, and has εHf (zircon) and εNd (whole rock) identical to those of Late Cretaceous granites in the core complex. These isotopic and field data indicate that Overlook- type monzogranite formed in situ through anatexis of host Cretaceous granites. A pervasive thermal event was required to stimulate this crustal melting. Gabbros from Lamoille Canyon and quartz diorite dated from 32 km away signal mantle- derived magmatism ca. 39– 37 Ma (U-Pb, zircon) was a driver of crustal melting and hybridization. Eocene 40Ar/39Ar apparent ages on hornblende and biotite are consistent with syn- to post- magmatic extensional exhumation and decompression. Thus, the core complex provides a window into trans- crustal magmatism and insight into how such magmatism affected the Nevadaplano orogenic plateau. This Paleogene thermal pulse, which may relate to removal of the Farallon slab by delamination of mantle lithosphere, involved partial melting of the upper mantle and transfer of magma and heat to the Nevadaplano crust. Lower- crustal melting of Archean(?) to Paleoproterozoic rocks resulted in Snow Lake Peak– type magmas, and middle- crustal melting of granite in the infrastructure yielded Overlook- type magmas. This crustal magmatism, as exemplified by the intrusions in the core complex, likely played a role in destabilizing the Nevadaplano and its later collapse during middle Miocene extension. The Paleogene intrusions and associated structural features also provide insight into the evolution of the core complex through either the buoyant upwelling of a melt- rich diapir (gneiss- dome model) or buoyant upwelling of the melt- rich middle crust synchronous with a west- rooted mylonitic shear zone (extensional shear- zone model). We favor a hybrid that incorporates both models. [ABSTRACT FROM AUTHOR]

We report fossils of the Halcyornithidae from the early Eocene London Clay of Walton-on-the-Naze (Essex, UK). The material includes remains of nine individuals of these small zygodactyl birds, which belong to at least seven different species, two of which are newly described. This documents a high species richness of halcyornithids in the London Clay, and these birds apparently underwent a significant radiation in the early Paleogene. One of the specimens includes a skull with a proportionally much smaller neurocranium than in Pseudasturides macrocephalus from Messel, suggesting an increased encephalization of halcyornithids towards the middle Eocene. A previously undescribed variation in sternum morphology of halcyornithids distinguishes the fossils we assign to the taxa Pulchrapollia and Cyrilavis and indicates that halcyornithids occupied disparate ecological niches. Furthermore, sternum morphology supports a sister group relationship between the halcyornithid taxa Pulchrapollia and Pseudasturides. The closest extant relatives of the Halcyornithidae remain elusive, but our new osteological data substantiate the hypothesis of a sister group relationship to the Messelasturidae, another group of Eocene birds with zygodactyl feet. [ http://zoobank.org/urn:lsid:zoobank.org:pub:DDC1768F-1389-4F36-92F6-46DA318A0C19 ]. [ABSTRACT FROM AUTHOR]

The Western Xihu Basin (WXB), part of the East China Sea Shelf Basin (ECSSB), demonstrates distinct structural differences between different sub-areas. Understanding the origin and mechanism of these differences is critical for unravelling the formation and evolution of the Western Xihu Basin and the ECSSB. Based on high-resolution 2D and 3D seismic data, we investigate the structural characteristics and evolution of the hinged margin and discuss the underlying formation mechanisms. The results suggest that, while controlled by NNE-, NE- and NW-striking major faults, there are distinct differences in the fault geometry, margin structure, fault displacement rate, and margin evolution in different basin areas. In contrast to the conventional division scheme which divides the WXB into three general sub-areas, our results suggest that the WXB should be divided into seven sub-areas with different tectonic structures and stress histories. The evolution of the WXB can be divided into three stages: (1) the synrift stage in the Palaeocene and early Eocene, when NNE-, NE- and NW-striking major faults were highly active and controlled the initial formation of the hinged margin structure; (2) late synrift stage in the late Eocene, when the faulting activity diminished, and the control of faults on the margin evolution decreased; (3) postrift stage from the Oligocene onwards, when active faulting ceased and sedimentation and differential basement subsidence became the main factors controlling basin evolution. The formation and reactivation of NW-striking faults under influence of the Izanagi-Pacific ridge subduction during the Mesozoic provided the basis for the differential evolution of the WXB in Cenozoic. [ABSTRACT FROM AUTHOR]

A new elasmobranch assemblage including 14 shark taxa, mainly lamniformes (9 taxa), is described from the Lower Eocene (NP 10–11) Kalinino Formation of the Alai River Basin, Baltai District, Saratov Region of Russia. The Nikulinka elasmobranch assemblage may have characterised inner neritic environments of the eastern part of the sub-boreal European paleobiogeographic region, being closely related to assemblages from the south-most sector of the boreal Western Siberian Province (southern Trans-Urals and Turgay straight). The absence of myliobatids in Nikulinka and Trans-Uralian localities may have been caused by the influence of Arctic water masses through meridional straits in early Ypresian. This is the first chondrichthyan assemblage from the Palaeogene of the Middle Volga Region, European Russia. [ABSTRACT FROM AUTHOR]

The Paleocene-Eocene thermal maximum (PETM; ca. 56 Ma) geological interval records a marked decline in calcium carbonate (CaCO3) in seafloor sediments, potentially reflecting an episode of deep- and possibly shallow-water ocean acidification. However, because CaCO3 is susceptible to postburial dissolution, the extent to which this process has influenced the PETM geological record remains uncertain. Here, we tested for evidence of postburial dissolution by searching for imprint fossils of nannoplankton preserved on organic matter. We studied a PETM succession from the South Dover Bridge (SDB) core, Maryland, eastern United States, and compared our imprint record with previously published data from traditionally sampled CaCO3-preserved nannoplankton body fossils. Abundant imprints through intervals devoid of CaCO3 would signify that postburial dissolution removed much of the CaCO3 from the rock record. Imprints were recorded from most samples but were rare and of low diversity. Body fossils were substantially more numerous and diverse, capturing a more complete record of the living nannoplankton communities through the PETM. The SDB succession records a dissolution zone/low-carbonate interval at the onset of the PETM, through which nannoplankton body fossils are rare. No nannoplankton imprints were found from this interval, suggesting that the rarity of body fossils is unlikely to have been the result of postburial dissolution. Instead, our findings suggest that declines in CaCO3 through the PETM at the SDB location were the result of: (1) biotic responses to changes that were happening during this event, and/or (2) CaCO3 dissolution that occurred before lithification (i.e., in the water column or at the seafloor). [ABSTRACT FROM AUTHOR]

Pycnodont fishes were a successful clade of neopterygian fishes that are predominantly found in shallow marine deposits. However, throughout their long 180 million year reign (Late Triassic–end Eocene), they made multiple incursions into both brackish and freshwater environments. This fossil record mostly consists of fragmentary dental material, but articulated specimens are known from Early Cretaceous lacustrine localities in Spain. This review article aims to document all non-marine occurrences of Pycnodontiformes throughout most of the Mesozoic and early Paleogene. This review highlights two interesting trends in the history of non-marine habitat colonization by pycnodonts: (1) a huge spike in non-marine occurrences during the Cretaceous; and (2) that most occurrences in non-marine localities occurred at the latest Cretaceous period, the Maastrichtian. The high number of colonization events within the Cretaceous lines up with extreme climatic events, such as high temperatures resulting in high sea levels which regularly flooded continental masses, allowing pycnodonts easier access to non-marine habitats. The increased presence of pycnodonts in brackish and freshwater habitats during the Maastrichtian might have played a role in their survival through the K/Pg extinction event. Freshwater habitats are not as vulnerable as marine ecosystems to environmental disturbance as the base of their food chain relies on detritus. Pycnodonts might have used such environments as a refuge and began to occupy marine waters after the K/Pg extinction event. [ABSTRACT FROM AUTHOR]

The release of over 4500 Gt (gigatonnes) of carbon at the Paleocene–Eocene boundary provides the closest geological analog to modern anthropogenic CO 2 emissions. The cause(s) of and responses to the resulting Paleocene–Eocene Thermal Maximum (PETM) and attendant carbon isotopic excursion (CIE) remain enigmatic and intriguing despite over 30 years of intense study. CIE records from the deep sea are generally thin due to its short duration and slow sedimentation rates, and they are truncated due to corrosive bottom waters dissolving carbonate sediments. In contrast, PETM coastal plain sections along the US mid-Atlantic margin are thick, generally having an expanded record of the CIE. Drilling here presents an opportunity to study the PETM onset to a level of detail that could transform our understanding of this important event. Previous drilling in this region provided important insights, but existing cores are either depleted or contain stratigraphic gaps. New core material is needed for well-resolved marine climate records. To plan new drilling, members of the international scientific community attended a multi-staged, hybrid scientific drilling workshop in 2022 designed to maximize not only scientifically and demographically diverse participation but also to protect participants' health and safety during the global pandemic and to reduce our carbon footprint. The resulting plan identified 10 sites for drill holes that would penetrate the Cretaceous–Paleogene (K–Pg) boundary, targeting the pre-onset excursion (POE), the CIE onset, the rapidly deposited Marlboro Clay that records a very thick CIE body, and other Eocene hyperthermals. The workshop participants developed several primary scientific objectives related to investigating the nature and the cause(s) of the CIE onset as well as the biotic effects of the PETM on the paleoshelf. Additional objectives focus on the evidence for widespread wildfires and changes in the hydrological cycle, shelf morphology, and sea level during the PETM as well as the desire to study both underlying K–Pg sediments and overlying post-Eocene records of extreme hyperthermal climate events. All objectives address our overarching research question: what was the Earth system response to a rapid carbon cycle perturbation? [ABSTRACT FROM AUTHOR]

Unraveling the Paleo-Kuril Arc's origins is key to understanding northwest Pacific tectonics. The Paleo-Kuril Arc is viewed as an intraoceanic arc from trench subduction between the Izanagi and Pacific Plates. Alternatively, several studies suggest the Paleo-Kuril Arc as a continental magmatic arc, hypothesizing the existence of a mid-oceanic ridge and Paleogene subduction, placing the Paleo-Kuril Arc near the Okhotsk Block's southern edge. This study clarifies these hypotheses, previously clouded by limited geochronological data on deposits in the Paleo-Kuril Arc. We conducted U–Pb dating to examine the origins of detrital zircons from the Cretaceous–Paleogene Tokoro and Nemuro Belts of the Paleo-Kuril Arc. Cluster analysis, merging new and existing data, identified two unique detrital zircon age clusters. The abundance of Precambrian zircons in Cretaceous–Paleocene Paleo-Kuril Arc sandstones (Type 1 Cluster) suggests a continental magmatic origin, supporting the ridge subduction model. However, an early Eocene shift to a consistent local volcanic source (Type 2 Cluster) highlights a significant provenance change. This geochronological evidence, indicating a separation from continental sources, calls for further research to decode the simultaneous development of sediment sources in different geological belts, potentially tied to the ridge subduction event. [ABSTRACT FROM AUTHOR]

During the re-mapping of the area for the Geological Atlas of Switzerland, a significant stratigraphic unconformity was discovered in the North Penninic (Valais) Bündnerschiefer and the Flysch series of the northern Prättigau. It separates different units of the Cretaceous Bündnerschiefer from the Palaeogene Flysch. We explain this observation by a basin conversion from extension to compression, which caused the initial deformation of the Bündnerschiefer in an accretionary wedge. Interlinked return-flow has created a new heterogeneous substrate for the flysch sediments and explains the different types of unconformities. The basin conversion coincided with high-grade metamorphism in the vicinity of the the South Penninic suture and the Austroalpine units, and the increased exhumation in the Austroalpine nappe stack. Detrital zircon dating confirms also a change from European to Austroalpine detrital sources in the flysch sandstones. We discuss a palaeotectonic model leading to hP/lT metamorphism of the Bündnerschiefer in the Late Eocene (c. 42 Ma). It appears that the flysch formations were also involved, but to a lesser degree by tectonic deformation from the late Early Eocene onwards, as the pervasive folding characteristic of the Bündnerschiefer is absent. This has been followed by a phase of S-directed backfolding. During the Oligocene and Miocene, more extensive deformation occurred by SE to NW compression and finally by probable westward thrusting and folding. Our main theme is the transition from passive to active continental margins, which in Alpine plate tectonic framework corresponds to the transition to flysch sedimentation by basin conversion. Our results show that the simultaneity of the transition from extension to compression, as indicated by the accumulation of flysch, shifted in time from south to north in the Alpine Tethys. [ABSTRACT FROM AUTHOR]

A splinter of charred wood was recovered from late Early Eocene volcanoclastic deposits underlying the lacustrine succession of the Messel-pit near Darmstadt (Hesse, Germany). Well-preserved anatomical details due to charring allow for an attribution of the splinter to the Oleaceae family. Within Oleaceae, the wood shows good agreement with the anatomical structure of recent members of the genera Olea, Chionanthus and Noronhia. However, due to the high variability of structural features within this group of genera, a reliable taxonomic placement is restricted to the monophyletic drupaceous subtribe Oleinae. The Splinter was cut loose from a tree of the local vegetation and charred by effects of the respective phreatomagmatic eruption, even under a low-fire regime. The specimen represents a rare example of a Pre-Quarternary wood that can be related directly to a radiometric age of 48.27–48.11 Ma (±0.22 Ma). [ABSTRACT FROM AUTHOR]

Premise of research. Macginitiea is an iconic and easily recognizable genus well known from the Paleogene of western North America and Kamchatka. Here we recognize new species and occurrences of Macginitiea from multiple sites in North America and discuss their implications for biogeography and evolution. Methodology. We studied leaves and inflorescences from multiple sites across North America. We used microcomputed tomography scans to illustrate the floret anatomy of Macginicarpa from Texas. Cuticles were examined using epifluorescence microscopy and maceration in Jeffrey's solution. Pivotal results. The distribution of Macginitiea suggests transberingial migration, similar to that in other platanoids like Platimeliphyllum. Macginitiea lived as far south as central Texas; few fossil platanoids are known from southern latitudes, even though most living Platanus species occur below 30°N. We document the cuticle anatomy of M. whitneyi , revealing a heavily striated cuticle with circular hair bases. Newly recognized species include those with a striking proclivity for basilaminar lobe development, including M. rannii sp. nov. from the Eocene of Wyoming, M. basilobata comb. nov. from the Paleocene of Montana, and M. rileyi comb. nov. from the Eocene of Texas and New Mexico. We also revise the taxonomy of Aralia wardiana (formerly Aralia digitata) and Platanus browni and show their affinities to Macginitiea. Using a broad concept of the gene regulatory networks governing lobe and stipule development, we hypothesize how different Macginitiea leaves could have developed their basilaminar lobes. Conclusions. We find that Macginitiea had a greater taxonomic diversity and a wider geographic range than was previously known. Among this diversity are several species with substantial basilaminar lobe development. Basilaminar lobes in modern and fossil platanoids tend to develop only when a leaf produces at or near the maximum number of lobes for that taxon. Influence of the same gene regulatory network may explain the similar appearance of stipules and basilaminar extensions in Platanaceae. [ABSTRACT FROM AUTHOR]

The Imini mining district (southern foreland of the intraplate Atlasic belt of Morocco) hosts the largest Mn resources of North Africa, consisting of two laterally extensive bodies of high-grade pyrolusite-rich manganese ore and a third discontinuous medium-grade coronadite-rich Mn ore in a ~ 10–15-m-thick Cenomanian–Turonian dolostone unit. Until now, the origin and timing of the Mn ore have been poorly constrained. New Pb isotopic ratios show that Triassic series (basalts and ferruginous sandstone) are likely the source of the metals. 40Ar/39Ar dating of K-Mn oxides shows that the Mn-rich orebodies formed during at least three periods: late Cretaceous to late Paleocene (> 58 Ma), late Eocene (ca. 36.3 Ma), and early Burdigalian to early Serravalian probably in two pulses at ca. 19–20 Ma and ca. 13 Ma. These periods coincide with three known building phases of the Atlasic relief during late Cretaceous, late Eocene, and the Early(?)-Middle Miocene. We therefore propose the Atlasic tectonics as the first-order control of the Mn mineralization. Periods with regionally high elevations modified the climate to wetter conditions that supplied meteoric water to feed temporary aquifers. Relief building created the required hydraulic head to sustain (1) fluid-rock interaction between O2-poor acidic fluids and the Triassic series, (2) migration of the metal-rich fluid, and (3) to overpressure fluid in the Imini depositional site. The decreasing thickness of Triassic series in front of the Imini anticline forced these low-temperature (< 100 °C) fluids to mix with oxygenated and alkaline ground waters in the karst system and precipitate Mn oxides. The N70°-oriented Atlasic tectonic structure controls the orientation of the Mn deposits. The late Eocene–Early/Middle Miocene uplifts generated additional supplies and/or in situ remobilization of the primary late Cretaceous medium-grade ore to form the high-grade pyrolusite-rich ore. [ABSTRACT FROM AUTHOR]

IODP Site U1509 (Expedition 371), New Caledonia Trough, provides a rare latest Cretaceous–Paleocene record from offshore northern Zealandia. We present new palynomorph and benthic foraminiferal assemblage data that show a transition from a latest Cretaceous vegetated sediment source region to a fully oceanic environment in the Paleocene. Latest Cretaceous (c. 68–66 Ma) non-calcareous claystone was deposited in upper bathyal paleodepths, with abundant plant microfossils that were likely transported in a northwest direction through the Aotea Basin region. A 2–3 Myr unconformity is identified at the Cretaceous/Paleogene boundary. Middle early–late Paleocene (c. 63.5–56 Ma) calcareous claystone shows evidence of deepening, deposited in middle bathyal or deeper paleodepths, and terrestrial input is minor. This latest Cretaceous to Paleocene deepening trend is consistent with inferred evolution of the Aotea and Northland basins further to the east, and other sparse northern Zealandia records, which show a common pattern of post-rift transgression consistent with long-term subsidence. Site U1509 allows for biogeographic extension and modification of the New Zealand Paleocene dinoflagellate zonation, description of a new dinoflagellate and pollen species, better inference of regional paleogeography, and may provide insights into the onset of western Pacific subduction initiation. [ABSTRACT FROM AUTHOR]

Various isotopic and palynological indicators have shown interspersed periods of aridity and humidity for the late Paleocene to early Eocene in central China, so the paleoclimate conditions remain unclear. This research investigates the environmental characteristics of a saline lake in the Jiangling depression, southwestern Jianghan Basin, from the Paleocene to the Eocene, using bulk-rock geochemistry in a 1280 m sediment core. The ratios of FeO/MnO, Al2O3/MgO, and C-value indicate a semi-humid to semi-arid climate in the early–middle Paleocene. There was a rapid shift to a humid climate during the late Paleocene to early Eocene, following a short time of intense dryness. The Eocene climate was arid, but experienced intermittent humidity. The variation trend of the CIA, CIW and PIA was similar to that of FeO/MnO, Al2O3/MgO, and the C-value, so chemical weathering of the surrounding rocks was controlled by climate change. The lake redox conditions in the Jiangling depression from the Paleocene to the Eocene were reconstructed using the ratios of U/Th, Ni/Co, and V/Cr. During humidity and alternations of aridity and humidity, the lake water received external water input, resulting in weak stratification, so the sediments were in oxidizing conditions. During aridity, lakes become endorheic, leading to sediments forming in reduced conditions. The salinity of the lake in the Jiangling depression from the Paleocene to the Eocene was determined through analysis of sedimentary sequences and the trend of the Sr/Ba ratio. In the early–middle Paleocene, lake salinity varied greatly. From the late Paleocene to the early Eocene, lake salinity decreased. In the Eocene, lake salinity increased and halite precipitated, but lake salinity finally decreased due to a humid climate. During the late Paleocene–early Eocene, the occurrence of multiple humid climates in the Jiangling depression were not merely regional effects. The most significant humidity was caused by a global hyperthermal (PETM), which caused a huge increase in precipitation in the whole of East Asia and even in low latitudes around the world. [ABSTRACT FROM AUTHOR]

Structural landform evolution and hydrogeochemical analyses are crucial for understanding the characteristics of karst groundwater systems and the development of deep karst formed by complex aquifers in a tectonic collision zone. Detailed structural landform evolution analysis was carried out along the large‐scale anticlinorium to investigate the temporal evolution of karst aquifer systems and karstification. Results showed that the tectonic activity included weak horizontal compression and slow vertical uplift during the Triassic to Middle Jurassic, forming a denuded clastic platform. This period was mainly preserved in the geological record as burial karst. From the Late Jurassic to the Early Cretaceous, the study area was strongly compressed by S–N‐trending stress, and developed E–W‐trending high‐angle imbricate thrust structures, which controlled the formation of folded and fault‐blocked mountains. Vertical multilayered strata underwent a strong horizontal extrusion, forming a large‐scale anticlinorium with secondary folds and faults. With the exposure of carbonate rocks due to rapid crustal uplift, karst began to develop, forming a vertical multilayer karst aquifer system and controlling the distribution of karst groundwater. The Fangxian faulted basin was formed from the Late Cretaceous to the Paleogene, whereby landforms were dominated by intermountain basins. Slow crustal uplift caused the retreat of the denudation line to the east, leading to an increase in hydrodynamic conditions and karstification, and the initiation of early karst groundwater systems. Since the Neogene, intermittent and rapid crustal uplift has led to the deepening of rivers, resulting in the formation of peak clusters and canyons, the development of deep karst, and the complete formation of karst groundwater systems. Combined with hydrogeochemical and borehole data, local, intermediate, and regional karst groundwater systems were identified. It has vital significance to the geological route selection or construction of deep‐buried tunnels and the utilization of karst groundwater. [ABSTRACT FROM AUTHOR]

There are few studies focused on spore and pollen clumps in paleopalynological samples, and these are only reports from the Northern Hemisphere. These aggregates may be of animal or floral origin. The goal of this contribution is to provide the first detailed study of spore and pollen clumps from the Southern Hemisphere, and to discuss their possible origin, botanical affinities, and pollination modes, based on their morphological characteristics, preservation and comparison with putative living representatives. Three fern spore clumps and 18 angiosperm pollen clumps were recognized in Maastrichtian-Danian La Colonia Formation sediments that outcrop at Chubut Province, Patagonia, Argentina. Most clumps are monospecific and composed of undamaged elements but some of them have two types of spore/pollen with corroded and/or fragmented exines. These findings represent the most diverse and abundant record of fern and angiosperm clumps from the Late Cretaceous and early Paleocene so far known from South America and the Southern Hemisphere. These results are indicative of the need for comprehensive large-scale studies on pollination of modern taxa and careful processing of palynological samples to lessen the already large bias in paleopalynological interpretations. The paucity of information on clumps in the fossil record has impaired our comprehension of dispersion/pollination in deep time. [ABSTRACT FROM AUTHOR]

We discuss the tectonic structure, seismic stratigraphy and evolution of the NW Sulu Sea using reprocessed 2D reflection profiles. The NW Sulu Sea is located between the Palawan continental shelf and the Cagayan Ridge and represents the northern part of the Sulu Sea, a marginal sea resulting from Paleogene extension and subsequent Neogene contraction due to convergence between the Palawan and the Philippine blocks. The basin consists of six seismo‐stratigraphic units overlying crystalline basement. Syn‐orogenic depocenters contain calibrated Middle Miocene to, possibly, Lower Miocene units, while rift‐related depocenters consist of uncalibrated but tentatively dated Paleogene to Lower Miocene units. Thickness and depth maps of the main units and bounding horizons differentiate the Piedra‐Blanca and the Rasa domains, separated by the NW‐Sulu‐Break major tectonic structure. Fault‐bounded rift‐related depocenters are strongly segmented. We interpret that NW‐SE and NE‐SW trending zones accommodate shape and trend variations of these depocenters. We suggest that these zones may link rift segments, recording different extensional deformation. Miocene thrusting and folding in the Piedra‐Blanca Domain and mudflow with associated gravitational structures in the Rasa Domain influenced the deposition of syn‐orogenic units. Rift structures inherited from rift segmentation may have conditioned the style and distribution of contractional deformation during the subsequent incipient reactivation during contraction. In the context of SE Asia, our results support that the timing of rifting of the NW Sulu Sea overlaps with the opening of the South China Sea and the North Palawan margin, which may indicate a common geodynamic driving force triggering extension. Plain Language Summary: The SE Asia region includes several basins partially floored by oceanic crust, frequently containing or bounded by volcanic island arcs. These basins are known marginal seas and, although it is critical to decipher the geodynamic evolution of the entire region, the structure and tectonic history of most of these marginal seas are still insufficiently known. The Sulu marginal sea lies between the Sulu Archipelago and the Palawan, Mindanao, Negros and Panay islands. The Cagayan Ridge separates the NW and SE Sulu seas, which show a contrasting seafloor morphology, resulting from Paleogene extension and subsequent Neogene contraction. In this work, we study the structure and tectonic evolution of the NW Sulu Sea based on the re‐processing and interpretation of seismic reflection profiles acquired in 1982 and 1987. We analyzed and calibrated the seismo‐stratigraphy of the sediment infill, determined the main tectonic and gravitational structures and the geometry and spatial distribution of depocenters. Our results show for the first time the basin‐wide overall structure and constrain tectonic models, describing the opening and, particularly, the contractional deformation of the NW Sulu Sea. This provides further information to understand the formation of the Sulu Sea and the evolution of convergent systems in SE Asia. Key Points: A multi‐stage tectonic evolution shaped the Piedra‐Blanca and Rasa structural domains separated by the gentle NW‐Sulu‐Break structureNW‐SE and NE‐SW trending accommodation zones define the geometry and location of the rift‐related oldest basin depocentersThrusts and associated folds deformed the Piedra‐Blanca and mudflows affected the Rasa domain during the contractional basin reactivation [ABSTRACT FROM AUTHOR]

Middle Eocene interbasaltic deposits of Hareø, West Greenland, have yielded a rich leaf and fruit record, which was described in the second half of the nineteenth century. In this study, we describe dispersed spores and pollen from the Aumarûtigssâ Member of the Hareøen Formation in order to obtain a more comprehensive picture of the late middle Eocene vegetation of West Greenland. The spore/pollen assemblage, derived from a resinite-rich coal bed, comprises 123 taxa, of which 14 belong to mosses, ferns and fern-allies, 14 to gymnosperms, and 95 to angiosperms. The most diverse groups of angiosperms are Fagales, comprising 27 taxa, and Rosales, represented by nine taxa. Along with conifers belonging to Pinaceae, these groups reflect the temperate character of the Hareø flora. In addition, a few 'exotic' elements include cycads probably belonging to an extinct temperate lineage that was widespread across the Northern Hemisphere during the Paleogene, palm trees, members of Mastixioideae and Santalaceae, both of which were characteristic elements of more southern warm temperate floras of Europe. A detailed comparison with macrofossil and spore/pollen assemblages of roughly coeval sites from Axel Heiberg Island (Canada), Spitsbergen (Arctic Ocean), and ODP site 151-913B in the Norwegian-Greenland Sea, show a highly consistent picture of the vegetation during this time. [ABSTRACT FROM AUTHOR]

A series of well-exposed Paleogene sedimentary successions in the Kohat Basin of northwestern Pakistan (western Himalayas), are used to document the development of Paleogene sedimentary sequence deposited in a clastic–carbonate–evaporate distally steepened to a homoclinal ramp setting. Larger benthic foraminifer stratigraphy, sedimentology and microfacies were used to reconstruct the depth of deposition of the sediments and to aid in reconstructing the subsidence history of the sedimentary basin through the Paleogene. Based on the timing of the cessation of marine sedimentation and the subsidence analysis of the Paleogene rocks of the Kohat Basin, we conclude that a proto-closure of the basin occurred in the early Eocene (Ypresian) at ca 50–49.5 Ma, followed by return of marine sediments, with full closure of the Tethys seaway in the middle Eocene ca 40–41.2 Ma (Lutetian), potentially resulting in diachroneity of emergence of basins along strike of the orogen. Paleogene Larger Benthic Foraminferal biostratigrphy and facies information in the Eastern Tethys segment of the Kohat Basin, Pakistan are presented. Distally steepened-homoclinal ramp deposits were found. The proto-closure of Tethys occurred around 49.5 Ma with complete closure at 41.2–40 Ma due to India-Asia collision. [ABSTRACT FROM AUTHOR]

Present study aims to locate potential reservoir zones in the Paleocene, Eocene and Oligocene sequences by analysing well log data of nine vertical wells in the exploration block MB-OSN-2004/1 in the Bombay offshore basin, Gulf of Cambay, India. The geophysical logs such as gamma-ray (GR), caliper (Cali), resistivity (LLD, LLS, and MSFL), photoelectric effect (PEE), neutron porosity (NPHI), and density (RHOB) are used to study the petrophysical characteristics of the identified reservoirs in this field. The relevant information from other sources like available report, mud log, and other open hole wireline log data, and local knowledge about the field are integrated with the petrophysical analysis. The cross-plots and mud log data show that the wells mainly consist of three types of lithology: shaly-sand, shale, and limestone, however, coal layers and pyrite are present at some places. Cross plots of thorium and potassium (from spectral gamma-ray log) show that the type of clay is mixed-layers of illite, montmorillonite and kaolinite in the Pipavav and Panna formations. Three of the nine drilled wells C-47-1, MTC-1, and MB-3-1 are identified by the petrophysical investigation as gas-bearing, principally in the Pipavav and Panna formations, with saturation ranging from 55% to 60% and porosity varying from 10% to 40%. Gas-bearing layers' thickness varies from 5 to 40 m and are primarily composed of clastic sediment with mixed carbonates in some locations. The remaining wells are water-bearing because the wells penetrating the silt formations are abundant in clay minerals, which keep the reservoir from releasing fluid and decrease its permeability. In addition, gas cannot rise because impervious shale layers are present in the columns of sand and calcareous sand. [ABSTRACT FROM AUTHOR]

The Western Ghats‐Sri Lanka biodiversity hotspot is home to three endemic Lygosomine (Reptilia, Scincidae) skink genera—Kaestlea, Ristella and Lankascincus. Phylogenetic reconstructions in the past have suggested a sister relationship between the Western Ghats endemic Ristella and the Sri Lankan endemic Lankascincus, while the placement of Kaestlea has been uncertain. We reconstruct a global, genus‐level, multi‐locus phylogeny of the sub‐family Lygosominae to ask if these endemic genera share an immediate common ancestor, that is, did they arise from a single dispersal event? Furthermore, to understand the possible centres of origin and dispersal routes of these three genera of Indo‐Sri Lankan skinks, we construct a time‐calibrated phylogeny and perform ancestral range evolution. We find that Kaestlea does not share an immediate ancestor with Ristella + Lankascincus. Therefore, their presence in the Indian subcontinent results from two independent colonization events. Both these dispersal events likely occurred during the late Palaeocene‐early Eocene from the Asian landmass. Our molecular dating and ancestral range evolution analyses add further evidence of probable transoceanic dispersal in skinks and early land connections between the Indian subcontinent and Asia. It also reveals that these skinks were some of the earliest lizards to disperse into the Indian subcontinent. [ABSTRACT FROM AUTHOR]

Isolated fossil bones from freshwater Upper Cretaceous (Maastrichtian) deposits in the Mahajanga Basin of northwestern Madagascar are identified as belonging to a gonorynchiform fish. Multiple elements representing the same bone, including opercles, hyomandibulae, frontals, and basioccipitals, indicate that only a single gonorynchiform species is present. The most diagnostic element is here named as a new genus and species, †Vango fahiny; the other elements likely belong to the same taxon. The Madagascan gonorynchiform material shares features with members of the subfamily Chaninae and is assigned to that group. It is similar to the extant milkfish Chanos chanos but can be easily distinguished from that species by numerous features, such as the basioccipital and maxilla being relatively shorter than those of C. chanos, and the opercle being overall rounder and having a shorter auricular process. The presence of a chanid in Madagascar in the Maastrichtian most likely represents an invasion of a marine lineage into fresh waters. The previously known Cretaceous fossils of gonorynchiforms are spread throughout the Tethys Sea in mid-latitude to northern regions from the east (e.g., Lebanon, Europe) through to the southwest (e.g., Mexico, Brazil). †Vango faniny gen. et sp. nov. represents the first Mesozoic/Paleogene record of gonorynchiforms in East Gondwana, comprising primarily Antarctica, Australia, Madagascar, and the Indian subcontinent. [ABSTRACT FROM AUTHOR]

A paleokarst system developed in the Upper Jurassic–Lower Cretaceous carbonate complex has been recognized in the Carpathian Foreland area. Well logs testing and core data as well as an acoustic imager, a microresistivity scanner and six-arm dipmeter images were used to identify and analyze the character of the paleokarst features. A detailed interpretation of microresistivity and acoustic image logs allowed for the identification of different types of karst forms, such as caverns; multidirectional fractures, including fractures widened by dissolution; and the type of sediments filling them. The analysis of the seismic survey was conducted by linking the paleokarst characteristic features recognized in the seismic image to the karst intervals determined from borehole data. The set of seismic attributes calculated from the analyzed 3D seismic data, including the RMS amplitude, instantaneous frequency, consistent dip, variance, sweetness and relative acoustic impedance, helped to delineate the zones of the paleokarst distribution. Within the interpreted paleokarst surface developed in the carbonate formations in the study area, there are sinkholes, limestone pavements and valleys. Furthermore, in the northwestern part of the analyzed area, the development of paleokarst forms is related to the presence of a relatively deep branch of a paleovalley formed in the Paleogene, as well as to numerous discontinuities developed in carbonate formations. The development of this type of larger karst form was probably controlled primarily by tectonic faults. The research conducted by the authors of this paper showed the widespread presence of paleokarst features in Upper Jurassic–Lower Cretaceous carbonate formations in the study area. A good spatial identification of the paleokarst surface can be important in a regional context, since the highest part of the profile of carbonate formations is the most important reservoir for geothermal or hydrocarbon resources in this region. [ABSTRACT FROM AUTHOR]

Atera Fault clay gouges were collected for age dating near Kawaue, Nakatsugawa City, Central Japan, and the results integrated within its complex geological history. The results form an internally consistent data set constrained by extensive geochronological data (AFTA, ZFTA, CHIME) and support the application of gouge dating in constraining timing of brittle deformation in Central Japan. The Atera illite age data complete recently obtained limited illite fault gouge age data from underground exposure in the Toki Granite; the new illite age data are identical within error. The age of the heterogenous welded tuff breccia zone (Atera 1) ranges from 40.6 ± 1.0 Ma to 60.0 ± 1.4 Ma, whereas ages of the fault core gouge sample (Atera 2) range from 41.8 ± 1.0 Ma to 52.7 ± 1.2 Ma. The finest < 0.1 µm fraction of the fault breccia and fault core gouge yield ages around 41 Ma, identical within error. The new illite age data indicate brittle faulting and a following geothermal event occurring in the Paleogene–Eocene, similar to the nearby Toki Granite area and confirm they were both synchronous with a post-intrusive pluton exhumation. The Atera Fault illite age data provide additional insights into an integrated, regional-scale record of the tectonic displacement of Central Japan and might be influenced by large-scale tectonic processes such as the Emperor sea mount kink around 55 to 46 Ma with fault initiation around 50 Ma and brittle fault cessation or reactivation around 40 Ma in the Eocene. [ABSTRACT FROM AUTHOR]