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Detailed sedimentological, geochemical, palynological, and aquatic-microfossil analyses on a new composite profile (Para-Reference Profile Schöningen 13 II and Zeugenblock 13 II [2018]) exposed at the archaeological excavation site of Schöningen 13 II reflect several phases of newly recorded lake level fluctuations and vegetation changes. A pronounced deforestation and the expansion of grasses and herbal plant communities characterize the first steppe (open woodland) phase, which follows the interglacial forest communities. A succeeding tripartite woodland phase predominantly marked by Betula and Pinus is followed by another rather dry steppe phase and a second woodland period, which includes the famous archaeological “spear horizon” 13 II-4ab. Transition into a cold period is indicated by progressive desiccation of the lake and a shift to a steppe/tundra vegetation. Novel 3D images of the 10 most characteristic phases of the Reinsdorf sequence have been constructed based on the botanical data (macro remains as well as palynomorphs), terrestrial vertebrate faunal, geochemical, sedimentological, and previously established data from aquatic microfossils. In addition, a tentative correlation between the post-interglacial phases of the Reinsdorf sequence and Marine Isotope Substages 9d–9a, based on biostratigraphical as well as sedimentological data, is proposed.

The Lemau Formation is a rock formation that forms the Bengkulu Basin in the Bengkulu Strip. The rocks in this formation contain hydrocarbon reserves in the form of coal. There has yet to be any research on the palynomorphs in the coal-bearing rocks in this formation. Palynomorph analysis was performed on nine samples from the P.T. Bara Indah Lestari, Seluma. The study aims to reconstruct the paleoenvironment and age of the coal-bearing rocks. The sampling technique uses stratigraphic measurements and hydrogen peroxide preparation. There were four changes in the depositional environment, namely the deposition of BIL 10-BIL 11 in the form of a freshwater peat swamp environment and BIL 12 in the form of a mangrove environment in the Early Miocene marked by the presence of Florschuetzia levipoli. The environment changed to a lagoon, indicated by the presence of foraminifera lining test and dinocyst in the deposition of BIL 13-BIL 15 samples in the Middle Miocene with a marked presence of Alnipollenites verus. The environment changed again during the deposition of BIL 16-BIL 18 to become a mangrove environment in the Middle Miocene. Overall, the paleoenvironment of the Lemau Formation is a freshwater peat swamp to a lagoon. Environmental changes are possible due to tectonic activity and climate change.

Archaeological remains of brachyurans (e.g. crabs) are often overlooked as potential paleoenvironmental and paleoclimatical proxies in contrast to other marine and terrestrial invertebrates such as mollusks and landsnails. The potential for fine-scale regional paleoclimate reconstruction based upon these organisms' behavioral ecology has yet to be examined. We present novel isotopic analyses of the remains of a semiterrestrial freshwater crab (Potamon potamios) endemic to southwest Asia recovered from the archaeological site of Khirbat al-Mudayna al-’Aliya (KMA). KMA lies on a southern tributary of the Wadi al-Mujib in the Hashemite Kingdom of Jordan, approximately 40km east of the Dead Sea. Excavations here recovered architecture, artifacts, and ecofacts dating to a single-period occupation during the early Iron Age (∼1000cal BCE). Oxygen and carbon isotopes from these brachyuran remains were analyzed in conjunction with a two-year isotopic and morphometric study of the modern potomonautid population near the archaeological site and at nearby wadi systems to assess whether the isotopic values of modern crab populations correlated with variables such as temperature, including isotopic study of the pools in which crabs were found. In turn, these data could be used to reconstruct paleoclimate or paleoenvironment in the archaeological population. The high correlation in oxygen isotope values between crab carapaces and the water of the pools in which they were sampled suggest that variability in isotopic values of crab specimens recovered from KMA is tracking ancient human capture of these organisms across potentially different pools. Further, intra-year variability in isotopic values in modern crab carapaces as well as the similarity of isotopic values across wadi systems with different environments suggest thatP. potamiosremains cannot be used as reliable paleoenvironmental indicators. The implications of this research will have significance for archaeologists and other researchers in the study of paleoenvironment and paleoecology, and bears upon human mobility, resource acquisition, and human-nonhuman animal relationships.

International audience; The late Carboniferous–early Permian represents a key period in the Phanerozoic history, given the major global geodynamic and climate modifications. The aim of this work is to better understand the context and characteristics of the sedimentation recorded in the continental environments of eastern equatorial Pangea at this time, through the example of the Autun Basin (northeastern Massif Central, France). The Autun Basin contains the historical stratotype of the Autunian continental stage, and its stratigraphy was recently improved by accurate numerical ages. This basin formed in an extensional tectonic context during the latest stages of the Variscan orogeny, and it is essential to study its paleoenvironmental evolution to provide new insights into the sedimentary evolution of contemporaneous surrounding basins. Using field and subsurface data, we propose a refined sedimentological model for the Autun Basin, relying on updated facies interpretations, organic matter content fluctuations, and sequence stratigraphy concepts and correlations. The continental environments of the lower sedimentary succession of the Autun Basin, previously considered to be fluvial and lacustrine, are herein re-interpreted as mainly lacustrine, comprising fine-grained organic matter-rich deposits, and supplied by coarser-grained deltaic siliciclastic sediments, without preservation of strict fluvial sedimentation. The determination of the sequence stratigraphy cycles, strengthened by the quantification of the organic matter content, and reflected by the temporal succession of progradational and retrogradational trends, is used to determine new correlations between several sections, as well as to reconstruct the paleoenvironment evolution at the Carboniferous–Permian transition. This study provides evidence that the sedimentation area of the Autun Basin at the time of its filling was much larger than the preserved basin area, and suggests connections with contemporaneous neighboring French basins, pointing to a large sedimentary system in the northeastern Massif Central area rather than narrow and isolated basins.

The present study aims to investigate the origin, type, thermal maturity and hydrocarbon generation potential of organic matter and paleo-depositional environment of the Early Paleocene (Danian) Hangu Formation outcropped in the Kala-Chitta Range of Northwest Pakistan, Eastern Tethys. Organic-rich shale and coal intervals were utilized for geochemical analyses including TOC (total organic carbon) and Rock–Eval pyrolysis coupled with carbon (δ13Corg) and nitrogen (δ15Norg) stable isotopes. The organic geochemical results showed that the kerogen Type II (oil/gas prone) and Type III (gas prone) dominate the investigated rock units. The TOC (wt%) and S2 yield indicate that the rock unit quantifies sufficient organic matter (OM) to act as potential source rock. However, the thermal maturity Tmax°C marks the over maturation of the OM, which may be possibly linked with the effect attained from nearby tectonically active Himalayan Foreland Fold-and-Thrust Belt system and associated metamorphosed sequences. The organic geochemical analyses deciphered indigenous nature of the OM and resultant hydrocarbons. The δ13Corg and δ15Norg stable isotopic signatures illustrated enrichment of the OM from both marine and terrestrial sources accumulated into the Hangu Formation. The Paleo-depositional model established using organic geochemical and stable isotopic data for the formation supports its deposition in a shallow marine proximal inner shelf environment with prevalence of sub-oxic to anoxic conditions, a scenario that could enhance the OM preservation. Overall, the formation holds promising coal and shale intervals in terms of organic richness, but due to relatively over thermal maturation, it cannot act as an effective source rock for liquid hydrocarbon generation and only minor amount of dry gas can be expected. In implication, the results of this study suggest least prospects of liquid hydrocarbon generation potential within Hangu Formation at studied sections.

This article is the result of archaeological and paleoenvironmental investigations carried out within the scope of the ANSOR project in the Sorraia valley (Coruche), on the left bank of the Lower Tagus. In the analysis of settlement dynamics between 5500 and 1800 a.n.e. we considered four moments: 1) The first peasant societies of the ancient Neolithic; 2) The Middle and Late Neolithic; 3) Chalcolithic; 4) The Early Bronze Age. The Sorraia valley was also framed in the framework of the Center and South of Portugal during the period under analysis. Interpretative models are presented for changes in the implantation patterns in the four stages under study, oscillating between paleoenvironmental factors and the socio-economic changes registered in the old peasant societies., Este artículo es el resultado de las investigaciones arqueológicas y paleoambientales realizadas en el ámbito del proyecto ANSOR en el valle de Sorraia (Coruche), en la margen izquierda del Bajo Tajo. En el análisis de la dinámica de asentamiento entre el 5500 y el 1800 a.n.e. consideramos cuatro momentos: 1) Las primeras sociedades campesinas del Neolítico Antiguo; 2) El Neolítico Medio y Reciente; 3) El Calcolítico; 4) La primera Edad del Bronce. El valle de Sorraia se sitúa también en el marco del Centro y Sur de Portugal durante el periodo analizado. Se presentan modelos interpretativos de los cambios en los patrones de implantación en las cuatro etapas estudiadas, dependiendo de los factores paleoambientales y de los cambios socioeconómicos registrados en las antiguas sociedades campesinas.

The present study focuses on archaeobotanical analyses performed at the Phoenicians site of Motya, a small island (ca. 45 ha) located in the Stagnone di Marsala, in western Sicily.The study of macro-remains focused on two closed contexts: a votive favissa by the sacred area of “Cappiddazzu”, and a disposal pit in Area D, both dating between the 8th and the 6th century BC. In the latter context, palynological analyses were also performed. The study allows to reconstruct sacred and secular aspects of human- environment interactions of Phoenicians at Motya, also providing information regarding past environment. Concerning the ritual sphere, ceremonial meals likely accompanied animal sacrifices. Food and flower offerings are also attested. Interesting is the finding of officinal plants and plants toxic to livestock. From the secular perspective, information was gathered on human diet, crop processing, import products and land exploitation. Finally, a combination of palynology and anthracology has allowed to describe the environment and highlight changes that occurred with time.

Application of Brantingham's (2003) neutral model of stone tool raw material procurement to a real landscape with real stone source locations, and the location of a known archaeological site.

(IF 3.09; Q1); International audience; Holocene palaeoecological studies in tropical Africa are rare because most lakes either dried out at the termination of the African Humid Period or have since filled up. However, tropical sedge marshes can be an alternative to perform long-term ecological studies. The Lopé National Park (LNP) in Gabon is a mosaic of forest and savanna enclosed in the equatorial forest, where open areas facilitated the development of peat marshes accumulating several-meter-thick sediment. In order to reconstruct the historical dynamic in these marshes through a local and regional point of view, we compared sedimentological, continuous X-ray fluorescence, and stable isotopic analyses on sediment cores from six herbaceous marshes in the LNP. A reliable chronological frame was based on 50 14C dates, over the last 2500 years in most sites, and reaching 9,000 years in one marsh. We show that the origin of these marshes is a major hydrological change, 3450 and 2300 years ago, that affected the entire region, almost concomitantly with the diffusion of Iron Age population. The sedimentation within marshes is homogenous with low intra-site variability. In contrast, high inter-sites variability evidences that the functioning of the marsh itself exerts a much more significant influence than in lakes. However, a regional event is recorded between 1400 and 800 years ago, concurrently with an archaeological trace hiatus throughout the forest hinterland of West Central Africa.Introduction

The Sichuan Basin is one of the largest petroliferous basins in China. The continental fluvial‒lacustrine sediments of the Upper Triassic Xujiahe Formation and the Lower Jurassic Zhenzhuchong Formation yield diverse fossil organisms and host one of the most important gas reservoirs in thebasin. However, paleontological implication for the paleoenvironment and hydrocarbon source is less documented. Here, we report, for the first time for this basin, results from palynofacies analyses combined with thermal alteration data in the Early Mesozoic deposit of the Qilixia section, northeastern Sichuan Basin. The results show that, organic matters in sediments are dominated by phytoclasts, with less abundant palynomorphs and a few amorphous organic matters (AOMs). Four palynofacies assemblages were identified, reflecting depositional settings in a general proximal and oxicfluvial‒deltaic environment, with two distal-proximal sedimentary cycles. The prominent dominance of opaque phytoclasts within the lower Zhenzhuchong Formation may be related to frequent wildfires across the Triassic-Jurassic transition. Palynofacies data (especially the relative abundanceof opaque phytoclasts) may reflect 405 kyr eccentricity cyclicity pattern. The palynofacies and thermal alteration index (TAI), combined with geochemical data indicate the presence of type III kerogen in mature to post-mature phases, suggesting gas potential of the Xujiahe and Zhenzhuchong formations in the northeastern Sichuan Basin. This study provides significant implications for better understanding the paleoenvironment variationsduring the Triassic-Jurassic transition and the future gas exploration in this area. Also funded by the National Science Foundation of China (NSFC41702004, 41790454, 41572014, 41688103), Strategic PriorityResearch Program (B) of the Chinese Academy of Sciences(XDB18000000, 26000000), the State Key Laboratory ofPalaeobiology and Stratigraphy (20172103, 20191103)

The growth history of the Tibetan Plateau provides a valuable natural laboratory to understand tectonic processes of the India–Asia collision and their impact on and interactions with Asian and global climate change. However, both Tibetan Plateau growth and Asian paleoenvironments are generally poorly documented in pre-Pliocene times and reflect limited temporal coverage for different parts of the plateau. In this paper, the 238 m thick Cenozoic sediments in the Hongzhuang section of the Xunhua Basin were tested and analyzed via paleomagnetic and environmental magnetic methods. The formation age was determined, and the evolution history of the regional climate environment was analyzed. The magnetostratigraphy study shows that the sediments record a continuous sequence of geomagnetic polarity changes from C5ACn to C10r, which spans an interval of approximately 30~14.3 Ma from the early Oligocene to the middle Miocene. The magnetic susceptibility of the Hongzhuang section is basically similar to the deep-sea oxygen isotope fluctuation, indicating that the monsoon climate change indicated by the magnetic susceptibility is affected by global temperature. It is worth noting that at ~27 Ma and ~15 Ma, there is a negative correlation between magnetic susceptibility and deep-sea oxygen isotope, and magnetic susceptibility lags behind the increase in deep-sea oxygen isotope. Combined with the change in the sedimentary rate curve, we explain the asynchrony between the magnetic susceptibility and the deep-sea oxygen isotope around ~27 Ma and ~15 Ma. As the uplift of the plateau leads to the enhancement of the East Asian summer monsoon, the soil formation in the region is strengthened, resulting in an increase in magnetic susceptibility. At the same time, the rapid uplift of the plateau caused the erosion of the surrounding mountains to strengthen, and the input of near-source materials may promote the increase in magnetic susceptibility.

The organic-rich shale of the Permian Taiyuan Formation (TYF) and Shanxi Formation (SXF) in the Southern North China Basin (SNCB) is considered a potential shale gas source. The shale was formed in a marine-continental transitional sedimentary environment, which has rarely been studied, with the enrichment mechanisms of organic matter (OM) remaining unclear. This study investigated the controlling factors and enrichment mechanisms of OM by analyzing the total organic carbon (TOC) content, paleoclimate, paleoproductivity, sedimentation rate, redox, and paleosalinity. The TOC of the TYF ranged from 0.92 to 7.43 wt.%, with an average of 2.48 wt.%, which was higher than that of the SXF (TOC = 0.36–5.1 wt.%, average of 1.68 wt.%). These geochemical indices suggest that both the TYF and SXF were deposited in warm and humid paleoclimates, with relatively high biological productivity and sedimentation rates. During the deposition process, the TYF experienced frequent transgression and regression events, leading to an enhancement of water reducibility, a relatively high sedimentation rate, reduced OM oxidation, and rapid deposition of OM, which were conducive to the preservation of OM. Moreover, a high biological productivity increased respiratory oxygen consumption in the water column, which could lead to OM accumulation. However, the regression event experienced by the SXF reduced the paleoproductivity and sedimentation rate and increased water oxidation, leading to a decrease in OM. The main controlling factors for the enrichment of OM in the TYF and SXF were the sedimentation rate, paleoproductivity, and redox conditions, thus establishing the enrichment models for OM in the TYF and SXF. This study is conducive to understanding shale enrichment mechanisms and guiding shale gas exploration.

The ca. 300 ka Paleolithic sites of Schöningen in northern Germany yielded a number of localities with archeological and paleontological remains representing a rich paleoenvironmental record of the late Middle Pleistocene in northern Europe. An important line of research focused on the ichnology of two localities: Schöningen 13 I-Fs2 and Schöningen 13 II-2 Untere Berme. Here we present the first detailed study of these fossil footprints, which provides insights on Schöningen's paleoenvironment and a snapshot of the mammals once living in the area. Herds of elephants and other species of herbivores congregated along the muddy shores of a paleolake during birch, pine and grass-rich woodland phases. In addition, three potential hominin footprints, probably belonging to a late Homo heidelbergensis, are recorded at Schöningen 13 II-2 Untere Berme. This confirms the complementary potential of ichnology in reconstructing a reliable picture of prehistoric sites.

This study investigated, in detail, the characteristics of the Late Triassic fine-grained sediments in the third member of the Xujiahe Formation (Xu-3 Member), in the Western Sichuan Depression, and the paleoenvironmental evolution during their deposition through petrological interpretation, mineralogical composition characterization, and element geochemical analysis. According to the mineralogical composition, the Xu-3 Member can be divided into two petrological types, namely clayey fine-grained felsic sedimentary rocks and lime fine-grained felsic sedimentary rocks. The main mineral components are siliceous, clay, and carbonate minerals. Through the cluster analysis of major elements, all samples could be divided into two types with different major elemental characteristics. Trace elements exhibited distinct Sr depletion, relative enrichment of large ion lithophile elements, and high field strength elements. Two REE enrichment patterns were observed, which could be attributed to differences in the provenance area and tectonic background. The paleoclimate of the sedimentary area was warm and humid, but it was hotter and drier in the southern and central parts of the depression. The change trend of paleo-productivity was consistent with the paleoclimate. The waters in the sedimentary environment were mainly brackish water to saline water, with fresh water in the southern part of the depression. The paleo-redox conditions of the waters were mainly sub-oxidation to sub-reduction, but the southern part of the depression was more oxidative. The provenance area experienced a moderate degree of chemical weathering under a warm and humid paleoclimate, same as the depositional area. However, the depositional environments differed between the northern and south-central parts of the depression.

Despite belonging to an important time slice in the geological history, the Eocene shallow-marine beds of the Alborz region in Iran have received little attention from researchers. We selected two stratigraphic sections (Mojen and Kalateh) ascribed to the Ziarat Formation as suitable representatives for the current analysis, emphasising on their constituent microfacies and paleoenvironmental implications. The biotic communities are characterised by larger benthic foraminifera (LBF), coralline algae, corals, and bivalves as the major carbonate facies components. The microfacies gradients and paleoenvironmental analysis suggest deposition in a shallow-marine oligotrophic ramp environment within two platform stages. Both these stages indicate an increase in water depth from the inner to the middle ramp settings with spatial distribution of the LBF and other benthic components. Our data support the previous view that the early Eocene witnessed an increase in LBF taxa with near obliteration of the coral reefs in the sedimentary platforms across the Tethys. The corals reinitiated building reefal structures in the Middle Eocene, marking an important phase in the Tethyan paleoenvironmental evolution.

By performing scanning electron microscopy, microscopic observations, whole-rock X-ray diffraction analysis, organic geochemistry analysis, and elemental analysis on drill core specimens and thin sections, in this study, we classified the shale types of the Wufeng Formation-Member 1 of the Longmaxi Formation in western Hubei, southern China, and explored the development characteristics and formation environments of the different shale types. The results show that (1) the shales of the Wufeng Formation-Member 1 of the Longmaxi Formation are composed of three types of shale: siliceous shale, mixed clay-siliceous shale, and clay shale. The siliceous shale is a type of shale unique to deep-water environments; clay shale is the main type of shale formed in shallow-water environments; and mixed clay-siliceous shale falls between the two. (2) The changes in shale type are characterized by multiple depositional cycles in the vertical direction with strong heterogeneity and an obvious tripartite character, and the siliceous shales gradually thicken as they laterally extend northwestward, with their last depositional cycle gradually ending at a later time. (3) The Late Ordovician-Early Silurian paleoenvironment can be divided into six evolutionary stages (A, B, C, D, E, and F) from early to late. In particular, the sea level was relatively lower in stages A and F when the bottom water was mainly oxygen rich with higher terrigenous inputs and a lower paleoproductivity, which led to the formation of clay shales poor in organic matter but rich in terrigenous quartz clasts. The sea level was higher in stages B, C, and D when the bottom water was anoxic with lower terrigenous inputs and a higher paleoproductivity, which led to the formation of siliceous shales rich in organic matter and biogenic silica. The total organic carbon (TOC) contents of siliceous shales decrease in the order of stage C > stage D > stage B, which is mainly attributed to the different degrees of water restriction in the three stages and the consequently different paleoproductivities. Stage E corresponds to the mixed clay-siliceous shales, the depositional environment of which is between those of the siliceous shales and the clay shales, thereby resulting in the mineral composition and TOC content of the mixed clay-siliceous shales being between those of the other two shale types.

The Research 2013 of the multi-layered archaeological settlement “Irkineyevo. Site Yelchimo-3” allowed to discover a stratified complex of the Upper Paleolithic site, aged 12–11 thousand years ago, in the Northern Angara region. The geological position of the cultural horizon connected with a complex of alluvial soils in a middle part of deposits of the first terrace rising above the floodplain of the Angara River, the preservation of archaeological materials in situ context, the zoo-archaeological collection in combination with the stone inventory provided highly informative data. The goals of research included the reconstruction of paleoenvironment and life support ways of the ancients in conditions of a point archaeological object. Spatial analysis showed the localization of cultural remains reflecting a cycle of multi-event activity in a hunting camp. The level of food life support is characterized by the species composition of the fauna. With the dominance of the reindeer remains the bones of birds, wolfs, roe deer and primeval bison were met here. The activity carried out on the site included the organization of the temporary camp, arrangement of a fire and resting place, food preparation and consumption, butchering of animals and preparation them to transportation. The main task of the inhabitants of the site was meat preparation for the future. Raw stone processing was situational in nature. Among the knapping products: wedge-shaped cores, flakes; blade-like flakes and micro blade-like flakes. The collection of tools consists of scraping-cutting tools (including retouched flakes), pebbly hammer-stones, and a piece of the red deer point. The analysis fulfilled by the authors indicated that the episode of the hunting camp functioning had a single-shot character during the autumnwinter period. The duration has been determined by the ratio of the number of harvested animals and the acts of hunting activity.

International audience; Located in the western part of the Paris Basin, the Eure catchment is marked by a several thousand years old human occupation. At the interface between several cultural groups since the Neolithic period (Gord, Artenac and Brittany), the Eure valley is a key archeological area for performing geoarchaeological investigations. The aim of this multiscale approach is to combine (I) geomorphological mapping in order to underline the geomorphological dynamics impacts on the taphonomy of settlement and archeological remains in the middle Eure valley; (II) geophysical surveys (Electrical Resistance Tomography) to obtain a 2D view of the sediment structures of palaeochannels; and (III) percussion drilling of sedimentary cores and sedimentological analyses. In addition, the sedimentary records of the Eure valley are a crucial indicator to reconstruct the hydro-sedimentary dynamics of the Eure catchment and the relationships between societies and their environment during the Late Holocene.; Localisé dans la partie occidentale du Bassin parisien, le bassin-versant de l’Eure présente une occupation humaine plurimillénaire. À l’interface entre plusieurs groupes culturels dès le Néolithique (groupes du Gord, de l’Artenac et de Bretagne), la vallée de l’Eure est un espace archéologique clef qui offre un cadre de recherche privilégié pour mettre en œuvre une approche géoarchéologique multiscalaire et diachronique combinant : (1) cartographie géomorphologique, comme outil permettant d’appréhender les biais taphonomiques dans la préservation des gisements archéologiques, (2) prospections géophysiques (tomographie de résistivité électrique) pour une reconstitution 2D de l’architecture du remblaiement alluvial, (3) acquisition et traitement des données stratigraphiques par carottage et analyses sédimentologiques. L’apport des archives sédimentaires fluviatiles est également mis en avant afin de reconstituer la trajectoire hydro-sédimentaire de l’Eure durant l’Holocène.

Este artículo presenta una revisión de los trabajos disponibles sobre las ocupaciones humanas tempranas y las condiciones medioambientales en el Magdalena Medio. Nos enfocamos en la temporalidad de la transición del Pleistoceno al Holoceno con el fin de evaluar la potencialidad de la región para albergar sitios con evidencias del uso del paisaje por parte de sociedades de cazadores recolectores. Para lograr esto, caracterizamos la zona, elaboramos el contexto paleoambiental y relacionamos los sitios arqueológicos, con lo cual aportamos a la generación de hipótesis sobre la dispersión humana durante ese período. This article presents a review of the available work on early human occupations and environmental conditions in the middle valley of the Magdalena river. The focus is on the temporality of the transition from the Pleistocene to the Holocene epoch in order to assess the potential of the region to house sites with evidence of landscape use by collecting hunter societies. To achieve this, the area was characterized, the paleoenvironmental context was elaborated, and the archaeological sites were related, thereby contributing to the generation of hypotheses about human dispersion during the period.

The early uplift of the Tibetan Plateau (TP) had a profound influence on the paleoenvironment and paleoclimate. However, we still have little information about the link between the paleoclimatic changes and flora ecosystem caused by the uplift. The Eocene fluvial-lacustrine sequences in the Gonjo Basin, eastern TP, provide excellent archives of the paleoecological and paleoclimatic responses to the surface uplift of the TP. In this study, we investigated a section of the middle Eocene Ranmugou Formation (47.8–>44 Ma) and used the sporomorphs assemblages, sedimentology, and geochemistry of the evaporites to reconstruct the paleoclimate and paleovegetation. The palynological assemblages and coexistence analysis reveal that the middle Eocene ecosystem in the Gonjo Basin was dominated by warm and humid temperate deciduous broad-leaved forests. The 87Sr/86Sr ratios (0.709942–0.710062) of all of the gypsum samples are higher than those of contemporaneous seawater, while the δ34S values (10.3–11.0%) are much lower, indicating a lacustrine environment. Combined with published palynological and paleoelevation data for eastern Tibetan lacustrine basins, we infer that the paleoenvironment changed from warm and humid deciduous broad-leaved forests during 47.8–>44 Ma, to cool and arid temperate forest during 44–40 Ma in the Gonjo Basin, and to arid and cool steppe-desert vegetation in the late Eocene Nangqian Basin. The changes in the paleoclimate and vegetation were primarily driven by the surface uplift of the Central Watershed Mountain, the high topography of which blocked the moisture from the Asian Eocene monsoon.

The bird fauna of the Loutra Almopias Cave comprised eight orders, 22 families, 41 genera and at least 47 species (68 different taxa) established based on 551 avian bone finds. The Loutra Almopias Cave is a new (26th) Pleistocene avian locality in Greece. About 92.5% of the material was dated to the Earliest Holocene (11.230 ± 110 y. BP), coming from the upper chamber of the cave, whereas an older assemblage was dated to the Late Pleistocene (37,880 y. ± 370/360 BP), coming from the floor chambers of the cave. Here is provided the first fossil record of 13 species in Greece (Buteo lagopus, Francolinus francolinus, Lagopus lagopus, Bonasa bonasia, Dryocopus martius, Lulula arborea, Bombicylla garrulus, Cinclus cinclus, Sylvia borin, Carduelis carduelis, Loxia curvirostra, Plectrophenax nivalis, and Emberiza cirlus). Three genera (Francolinus, Anthus and Riparia/Ptyonoprogne) were established for the first time in Pleistocene deposits in the country. The record of Fr. francolinus was the first one for the Balkans and Eastern Europe. At both sites inside the cave, regardless of their different age, the habitat preferences of the identified bird species indicated that the surrounding paleoenvironment included both grassy openlands (dominated by gramineans) and woodland (coniferous or mixed woods). In addition, rocky habitats were represented in the surroundings of the locality. The presence of small species of Perdicinae (26%) and corvids (34%) indicated the former existence and prevelance of open grassy fields and rocky environments. The Alpine chough was the most abundant species at both localities. In the Earliest Holocene it comprised 29.5%, whereas in the Late Pleistocene it reached 25.6% of the material. Such a representation suggests a natural non-human accumulation of the material, probably due to the feeding behavior of Bubo bubo. The Late Pleistocene record (19 taxa; 41 finds) included Falco sp. cf. F. peregrinus, Perdix perdix, Perdix sp., Alectoris graeca, Alectoris sp., Lagopus cf. lagopus, cf. Bonasa bonasia, Columba livia, Columba palumbus, Bubo bubo, Melanocorhypha calandra, Anthus sp., Turdus sp., Pica pica, Pyrrhocorax graculus, Loxia curvirostra, Coccothraustes coccothraustes, Pyrrhula pyrrhula, Fringillidae gen. indet., non-Passeriformes indet. and also suggests the site has been used by the eagle owl. The climate probably used to be drier and cooler than in the Earliest Holocene. The record of 17 woodland species from the Earliest Holocene that were absent in the Late Pleistocene could be explained by the more humid and moderate climate at the very end of the Pleistocene.

The Okhotsk Sea, which connects the high latitude Asian continent and the North Pacific, plays an important role in modern and past climate changes due to seasonal sea ice coverage and as a precursor of the North Pacific Intermediate Water. The long-term glacial-interglacial changes of sea ice coverage and its impacts on terrigenous transport and surface primary productivity in the Okhotsk Sea remain, however, not well constrained. Base on the paleomagnetic, rock magnetic, micropaleontological (diatom), and geochemical studies of the marine sediment core MD01-2414 (53°11.77′N, 149°34.80′E, water depth: 1,123 m) taken in the central Okhotsk Sea, we reconstruct the terrigenous sediment transport and paleoceanographic variations during the past 1550 thousand years (kyr). Seventeen geomagnetic excursions are identified from the paleomagnetic directional record. Close to the bottom of the core, an excursion was observed, which is proposed to be the Gilsa event ∼1550 thousand years ago (ka). During glacial intervals, our records reveal a wide extension of sea ice coverage and low marine productivity. We observed ice-rafted debris from mountain icebergs composed of coarse and high magnetic terrigenous detritus which were derived from the Kamchatka Peninsula to the central Okhotsk basin. Still during glacial intervals, the initiation (i.e., at ∼900 ka) of the Mid-Pleistocene Transition marks the changes to even lower marine productivity, suggesting that sea-ice coverage became larger during the last 900 ka. During interglacial intervals, the central Okhotsk Sea was either devoid of sea-ice or the ice was at best seasonal; resulting in high marine productivity. The weaker formation of Okhotsk Sea Intermediate Water, lower ventilation, and microbial degradation of organic matter depleted the oxygen concentration in the bottom water and created a reduced environment condition in the sea basin. The freshwater supplied by snow or glacier melting from Siberia and Kamchatka delivered fine grain sediments to the Okhotsk Sea. During the stronger interglacial intervals after the Mid-Brunhes Transition (i.e., Marine Isotope Stages 1, 5e, 9, and 11), strong freshwater discharges from Amur River drainage area are in association with intensified East Asian Summer Monsoon. This process may have enhanced the input of fine-grained terrigenous sediments to the central Okhotsk Sea.

The growth of the southern piedmont of the Himalayan boundary and its depositional setting has changed since uplift of the Himalaya due to continental Indian-Eurasian collision, which has resulted in variation in magnetic minerals in marine- and terrestrial-facies sediments. In this paper, we utilize rock magnetism data from the late Cretaceous to middle Eocene strata, including the Amile and Bhainskati formations from the Lesser Himalaya (western Nepal), to understand the mechanism controlling magnetic susceptibility (χ). The active tectonics strongly influenced saturation isothermal remanent magnetization (SIRM), HIRM, and hysteresis loops, forming both low-coercivity minerals in sediments with low χ from the terrestrial facies (zones I, IIIA, and V) and high-coercivity minerals in the sediments with high χ from the marine facies (zones II, IIIB and IV). Thermomagnetic κ-T curves and frequency-dependent χ (χfd%) values show that sediments with low χ and high χ carry magnetite with coarse non-superparamagnetic (SP) grains and hematite with SP grains, respectively. Comparing the χ data with the lithologic, sedimentary environments, geomorphic features, and sea level data, we propose that low χ values were mainly produced by an increase in terrigenous detrital influx during the regression period of the Tethys Sea, while high χ values formed in marine sediments, which prompted the appearance of ferromagnetic-antiferromagnetic and paramagnetic minerals during the transgression of the Tethys Sea.

The lakes at the southern Mongolian Plateau are sensitive to the variation of EASM changes during the Holocene, and hence the lacustrine records of these lakes provide prospects for understanding how lake environmental changes respond to EASM variation at different timescales. The interpretation of proxy indexes of lacustrine sediments is complex due to the various climatic or/and environmental factors influencing the processes during deposition and after deposition. In this study, the elements and colors of an 11.7-m lacustrine record from Chagan Nur at the southern Mongolian Plateau of northern China were analyzed to constrain the lake environmental changes during the Holocene. The results show that stable elements of Al, Si, K, Ti, Fe, and Rb are more related to surface erosion or/and vegetation coverage, and the variation of Sr is related to the lake-level change in Chagan Nur. The element and color of the lacustrine records show that a small and shallow lake environment occurred at Chagan Nur during 11.7–10.5 ka, the lake level had increased during 10.5–7 ka, and then the lake shrank with strength surface erosion during 7–6.2 ka and from 2 ka to the present. The lake level and surface erosion changes of Chagan Nur have shown a direct response to EASM precipitation changes as reconstructed from the pollen record from the Chagan Nur Lake and other records from northern China.

The organic-rich shale of the Upper Cretaceous Qingshankou Formation is an important hydrocarbon source rock in Northeast China. In this study, taking the lacustrine shale in the Qingshankou Formation as an example, geochemical analysis, including total organic carbon (TOC), Rock-Eval pyrolysis, maceral compositions, X-ray diffraction (XRD), and biomarker analyses, were carried out on twenty-four shale samples to evaluate the geochemistry and environmental features of this shales. The Qingshankou lacustrine shales contains mainly Type I/II1 organic matter and is oil prone, with a good to excellent source rock. Vitrinite reflectance and Rock-Eval pyrolysis parameters show that the Qingshankou lacustrine shales is mainly in the mature stage and within the oil window. Biomarker composition of the shales provide evidence that the Qingshankou lacustrine shales was formed in a reductive sedimentary environment with relatively high salinity water. The organic matter came from a mixture of plankton, bacterial and land plants.

The characteristics of paleosedimentary environments are of great significance for the enrichment of organic matter (OM) and hydrocarbons in lacustrine shale. This study analyzed mineralogy, well logging data, organic geochemical parameters (total organic carbon and pyrolyzed hydrocarbon), inorganic geochemical parameters (major and trace elements), and multiple geochemical proxies based on inorganic geochemical parameters. These were used to reconstruct the paleosedimentary environment of the lower 1st Member of the Shahejie Formation (Es1L) to reveal OM and shale oil enrichment mechanisms and establish a shale oil enrichment model. The (Fe2O3+Al2O3)/(CaO + MgO), Sr/Ba, Rb/Sr, Cu/Al, and Th/U parameters indicate that the Es1L in Raoyang Sag was deposited in a paleoenvironment dominated by arid paleoclimate, reducing conditions, and saltwater. Paleoclimate, clastic influx intensity, preservation conditions, paleoproductivity, and paleosalinity all affect OM abundance. The OM accumulation in the shale of Es1L was mainly controlled by the high primary productivity of surface water due to algal blooms and moderate salinities, which was achieved using stratified water columns with low oxygen conditions in bottom water. As the main valuable sites for shale oil storage, carbonate mineral depositions are of great significance for oil enrichment. As the dominant lithofacies for oil enrichment, carbonate-rich shale and calcareous shale lithofacies were deposited under a drier paleoclimate, low clastic influx intensity, strong reducing conditions, high paleoproductivity, and moderate salinity paleoenvironment. Additionally, the profile of the shale oil sweet spot was determined through the combination of lithofacies, logging, and paleosedimentary environment data.

Significance Competition for common resources can make some species groups thrive and others decline. Flowering plants rose to dominance between 125 and 80 Ma, undergoing an explosive radiation that is believed to have impacted long-established plant groups like gymnosperms. Here, we show that the decline of conifers is strongly and directly linked to the increasing diversity of flowering plants. Both the fossil record and molecular data converge in clarifying the effects of abiotic or biotic factors on the speciation and extinction rates of conifers. These results imply that long-term biological interactions through clade competition can play a more important role in the rise and demise of major organism groups than mass extinctions., Competition among species and entire clades can impact species diversification and extinction, which can shape macroevolutionary patterns. The fossil record shows successive biotic turnovers such that a dominant group is replaced by another. One striking example involves the decline of gymnosperms and the rapid diversification and ecological dominance of angiosperms in the Cretaceous. It is generally believed that angiosperms outcompeted gymnosperms, but the macroevolutionary processes and alternative drivers explaining this pattern remain elusive. Using extant time trees and vetted fossil occurrences for conifers, we tested the hypotheses that clade competition or climate change led to the decline of conifers at the expense of angiosperms. Here, we find that both fossil and molecular data show high congruence in revealing 1) low diversification rates, punctuated by speciation pulses, during warming events throughout the Phanerozoic and 2) that conifer extinction increased significantly in the Mid-Cretaceous (100 to 110 Ma) and remained high ever since. Their extinction rates are best explained by the rise of angiosperms, rejecting alternative models based on either climate change or time alone. Our results support the hypothesis of an active clade replacement, implying that direct competition with angiosperms increased the extinction of conifers by pushing their remaining species diversity and dominance out of the warm tropics. This study illustrates how entire branches on the Tree of Life may actively compete for ecological dominance under changing climates.

espanolLos fosiles de invertebrados marinos se han considerado herramientas importantes para la recolecta de datos por edades y la interpretacion estratigrafica de los depositos de paleogenos de Asia Central, sin embargo, aun no se ha proporcionado informacion de la cuenca de Kopet-Dagh (NE Iran). En esta investigacion, se discuten los horizontes fosiliferos de la Formacion Chehelkaman en las secciones Sheikh y Ghaleh-Zou (que nunca antes se habian reconocido), ambos en el area Sheikh Syncline. Estos lechos sedimentarios se superponen a la Formacion de Pesteligh siliciclastica terrestre y son la primera evidencia de inundacion marina de la transgresion del Paleogeno en el centro de Kopet-Dagh. Los estudios paleontologicos sistematicos de fosiles de moluscos en esta sucesion condujeron a la identificacion de: diez generos, doce especies, dos subespecies de bivalvos, cinco generos y cinco especies de gasteropodos. El conjunto pertenece a cuatro horizontes fosiliferos diferentes: (1) Conjunto Dominado por Turritellidae (TDA), (2) Pycnodonte-Turkostrea horizonte, (3) Cordiopsis - Cardium horizonte, (4) Camas de concha Globularia en la seccion Sheikh y solo horizonte TDA en la seccion de Ghaleh-Zou. La edad de toda la sucesion es Ypresian tardio (Cuisian medio temprano). Esta edad esta basada en Cordiopsis subathooensis - Turritella subathooensis co-ocurrencia de la zona con las zonas de nannofosiles NP12 y NP13. El TDA en ambas secciones confirma la abundancia de nutrientes y su orientacion bimodal demuestra los efectos de las ondas oscilatorias en lugar de las paleocorrientes unidireccionales. Las altas tasas de bioerosion, incrustacion, fragmentacion, desarticulacion y corrosion de las conchas en Pycnodonte - Turkostrea horizonte revela altos volumenes de nutrientes y condiciones ricas en energia. Este intervalo, cubierto por la Cordiopsis - Cardium horizonte en una disposicion de pavimento, representa las condiciones estables despues de una tormenta. Los lechos de conchas de Globularia intercalados con lechos de marga, indican estabilidad y una tendencia cada vez mas profunda del medio ambiente terminando en lutitas y margas mas profundas de la Formacion Khangiran. EnglishMarine invertebrate fossils have long been considered important tools for age dating and stratigraphic interpretation of the Paleogene deposits of Central Asia, however information has not yet been provided from the Kopet-Dagh Basin (NE Iran). In this research, fossiliferous horizons of the Chehelkaman Formation at the Sheikh and Ghaleh-Zou sections (which have never been recognized previously), both in the Sheikh Syncline area, are discussed. These sedimentary beds overlay the terrestrial siliciclastic Pesteligh Formation and are the first evidence of marine flooding of the Paleogene transgression in the central Kopet-Dagh. Systematic paleontological studies of molluscan fossils in this succession led to the identification of ten genera, twelve species and two subspecies of bivalves and five genera and five species of gastropods. The assemblage belongs to four different fossilif-erous horizons: (1) Turritellidae Dominated Assemblage (TDA), (2) Pycnodonte - Turkostrea horizon, (3) Cordiopsis-Cardium horizon and (4) Globularia shell beds in the Sheikh section and only TDA horizon in the Ghaleh-Zou section. The age of the whole succession, based on Cordiopsis subathooensis - Turritella subathooensis Zone cooccurrence with nannofossil zones NP12 and NP13, is Late Ypresian (early middle Cuisian). The TDA in both sections confirms the abundance of nutrients and their bimodal orientation demonstrates effects of oscillatory waves rather than unidirectional paleo-currents. High rates of bioerosion, encrustation, fragmentation, disarticulation and corrosion of the shells in the Pycnodonte - Turkostrea horizon reveals high volumes of nutrients and energy-rich conditions. This interval, overlain by the Cordiopsis - Cardium horizon in a pavement arrangement, represents the stable conditions after a storm. The Globularia shell beds inter-bedded with marly beds indicate stability and a deepening trend of the environment, terminating to deeper marine shales and marls of the Khangiran Formation.

The Lucaogou Formation in the Jimusar Sag of the eastern Junggar Basin is an important sedimentary stratum accumulating huge amounts of lacustrine tight oil in China, where organic-rich rocks are commonly observed. Focusing on the Lucaogou Formation, a precise analysis of the inorganic and organic petrology and the inorganic geochemistry characteristics was conducted. The paleoclimate and paleoenvironment during sedimentation of the Lucaogou Formation were established, and the key factors that were controlling the accumulation of organic matter during this time were identified. The results of this study suggest that during the sedimentation of the Lucaogou Formation, the paleoclimate periodically changed from a humid environment to an arid environment. As a result, the salinity of the water and the redox environment fluctuated. During the sedimentation period, the lake showed sufficient nutrient supplies and a high primary productivity. The interval studies in the Lucaogou Formation were divided into five sedimentary cycles, where the first, second, and fifth sedimentary cycles consisted of cyclical paleoclimate fluctuations varied from a humid environment to an arid environment and shifted back to a humid environment with levels of salinity from low to high and decreased again. The third and fourth cycles have cyclical fluctuations from a humid to an arid environment and corresponding salinity variation between low and high levels. During the period when organic-rich rocks in the Lucaogou Formation deposited in the Jimusar Sag, the paleoclimate and the water body were suitable for lower aquatic organisms to flourish. As a result, its paleoproductivity was high, especially during the early period of each cycle. A quiet deep water body is likely to form an anoxic environment at the bottom and is also good for accumulation and preservation of organisms. Fine-grained sediments were accumulated at a low deposition rate, with a low dilution of organic matter. Therefore, high paleoproductivity provided a sufficient volume of organisms in the studied area in a quiet deep water body with an anoxic environment and these were the key factors controlling formation of organic-rich rocks.

Although palms are recognized as a plant group of tropical and sub-tropical ecosystems, in South America they can also be found in temperate savannas under certain conditions. Therefore, since these plants have been widely used as palaeoindicators in warm and humid climates, it is important to know what phytolith contribution these plants have made in temperate environments. El Palmar National Park (Argentina) protects the largest remnant of savanna palm, Butia yatay (Mart.) Becc., one of the southernmost palm communities in the continent. This modern analogue study assessed the variability of silica phytoliths in 15 selected species of plants, 20 mulch samples (organic horizon) and 60 soil samples that were collected in all the plant communities selected for this study: dense palm trees (DPT), shrubbery with isolated tall palms (SIP), psammophile steppe (PS) and humid psammophile steppe (HPS). Our results show that grasses exhibit the most diverse forms. Palms, sedges and dicots can be distinguished by the different proportions of several diagnostic morphotypes. Palm tree communities can be characterized based on a presence a high proportion of globular echinate and trapeziform sinuate/oblong phytoliths. Psammophile steppes have a high proportion of bilobate, polylobate and cross phytoliths and a low presence of globular echinate. Humid psammophile steppes show a high presence of bilobate, cross and dicot phytoliths with a low proportion of trapeziform sinuate/oblong phytoliths and an absence of globular echinate morphotypes. The ratio of palm to grass phytoliths allowed us to obtain differences between the palm groves, psammophile steppe and humid psammophile steppe ecosystems. These analyses can then be used to determine this type of ecosystem in temperate humid savannas. Phytolith assemblages provide an important record for the characterization of the plant-soil system and production-incorporation system in mixed communities as a tool in the construction of palm trees paleoenvironments. Fil: Patterer, Noelia Isabel. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Universidad Autónoma de Entre Ríos; Argentina Fil: Zucol, Alejandro Fabián. Universidad Autónoma de Entre Ríos; Argentina. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina Fil: Fernández Pepi, María Gabriela. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Brea, Mariana. Universidad Autónoma de Entre Ríos; Argentina. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina

The palynological content of the Lagarcito Formation at the East of the Sierras de Guayaguas, San Juan province, central-western Argentina, is analyzed. The study of the Albian palynoflora of the Lagarcito Formation at the La Yesera section, Sierras de Guayaguas, allowed the identification of 64 fossil taxa from eighteen productive samples. A detailed botanical assignation of the palynomorphs, and the statistical analysis of the palynoflora, was performed in order to characterize the local and regional plant distribution. Differences in the palynofloristic content of the three lacustrine episodes productive in palynomorphs, were discussed. At the base of the section, ferns and bryophyte spores dominate the palynoflora. The second and third lacustrine episode showed a prevalence of gymnosperms mainly represented by the monosulcate Cycadopites-Monosulcites complex. The freshwater algae corresponding to the aquatic community are abundant through the section. The presence of interstratified gypsum towards the top of each lacustrine episode indicates a drastical reduction in the lacustrine system due to high levels of evaporation. The comparison of the studied microflora with the palynoflora recovered from the La Cantera Formation in the same basin gave evidence of more humid conditions up in the stratigraphic column. Fil: Mego, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Pramparo, Mercedes Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Vento, Barbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina

We report on an accumulation of mummified southern elephant seals (Mirounga leonina) from Inexpressible Island on the Victoria Land Coast (VLC), western Ross Sea, Antarctica. This accumulation is unusual, as elephant seals typically breed and molt on sub-Antarctic islands further north and do not currently occupy the VLC. Prior ancient DNA analyses revealed that these seals were part of a large, Antarctic breeding population that crashed ~1,000 yr ago. Radiocarbon dates for Inexpressible Island mummies range from 380 to 3,270 yr before present, too old to have been created by Scott's Northern Party in 1912 and varying too widely in age to represent a catastrophic death assemblage. Skeletal measurements reveal that most Inexpressible Island mummies are adult or subadult males. The presence of male elephant seals on Inexpressible Island until several hundred years ago suggests that, at a minimum, it served as a haul-out site for the large Antarctic population and may have hosted a breeding colony. The conditions that allowed this Antarctic population to use the Ross Sea, the factors spurring its decline, and the implications for the adaptability and sensitivity of the species to environmental change all merit further study.

En Tunisie centrale, les accumulations carbonatées continentales quaternaires, dépôts lacustres et/ou palustres et encroûtements, sont très développées. Le bassin de Hajeb El Ayoun offre un bel exemple pour l'étude de ce type de carbonates. L'étude pétrographique et minéralogique met en évidence trois principaux faciès : 1/ des calcaires lacustres caractérisés par la présence de débris de lamellibranches et de tests de gastéropodes, 2/ des calcaires palustres caractérisés par des traits d'exposition subaérienne importante (microkarsts et fentes de dessiccation) et enfin, 3/ les encroûtements calcaires à traits pédogénétiques tels que les glæbules dans les sédiments meubles. Dans les dépôts, limoneux comme calcaires, le cortège des minéraux argileux est le plus souvent dominé par les palygorskites, ce qui indique un milieu lacustre confiné pour l'ensemble sédimentaire inférieur et des conditions climatiques arides à semi-arides pour les matériaux au-dessus des calcaires lacustres et/ou palustres. In central Tunisia, Quaternary continental carbonate accumulations of lacustrine and/or palustrine types are well developed. The Hajeb El Ayoun basin provides a good example to study these deposits. Petrographic and mineralogical investigations show three facies: 1/ lacustrine limestones with broken lamellibranches and gastropods tests, 2/ palustrine limestones, which are marked by an important subaerial exposition as indicated by microkarsts and desiccation cracks, and 3/ calcareous crust with pedogenetic features such as glaebules in loose deposits. Palygorskite is most often largely dominant among the clay minerals of silty and calcareous deposits, indicating a confined lake environment for lower materials and arid to semi-arid climatic conditions for those above the lacustrine and/or palustrine limestones.

The Pontocaspian (Black Sea - Caspian Sea) region has a very dynamic history of basin development and biotic evolution. The region is the remnant of a once vast Paratethys Sea. It contains some of the best Eurasian geological records of tectonic, climatic and paleoenvironmental change. The Pliocene-Quaternary co-evolution of the Black Sea-Caspian Sea is dominated by major changes in water (lake and sea) levels resulting in a pulsating system of connected and isolated basins. Understanding the history of the region, including the drivers of lake level and faunal evolution, is hampered by indistinct stratigraphic nomenclature and contradicting time constraints for regional sedimentary successions. In this paper we review and update the late Pliocene to Quaternary stratigraphic framework of the Pontocaspian domain, focusing on the Black Sea Basin, Caspian Basin, Marmara Sea and the terrestrial environments surrounding these large, mostly endorheic lake-sea systems. © 2018 The Authors

Prior to the development of the modern Amazonian drainage network during the Late Miocene-Early Pliocene, large areas of western Amazonia may have been occupied by an extensive lacustrine and wetland environment known as the Pebas and Acre systems. These depositional systems are thought to have formed in response to foreland subsidence east of the uplifting Andes. Based on the occurrence at a present-day elevation of 1600 m of fossil pearly freshwater mussels of the genus Anodontites (indet. species) in intermontane Chota Basin of northern Ecuador (the westernmost South American fossil record for this genus), we discuss their potential implications for understanding of westernmost limit of the Miocene wetland ecosystem and consequently a later timing for the regional uplift of the Eastern Cordillera. © 2018 Elsevier Ltd

Analysis of the sedimentary environment during the clastic formation process is of great significance for reservoir evaluation and desert prediction. This paper focused on the Paleocene in the West Lishui Sag, East China Sea Basin. XRF fluorescence diffraction and carbon and oxygen isotope tests were carried out on core samples from four wells. Based on the geochemical characteristics of the samples and the changes in the elemental ratios, combined with the lithologic characteristics and sedimentary structure of the samples, the paleoclimate, paleosalinity, paleobathymetric, paleoredox, paleotemperature, and other paleoenvironmental characteristics were analyzed. The results show that the characteristics of major and trace elements were similar in the lower Mingyuefeng Formation (E1m2), Upper Lingfeng Formation (E1l1), Lower Lingfing Formation (E1l2), and Yueguifeng Formation (E1y). The Paleocene in the West Lishui Sag was mainly in the reducing environment of brackish-salt water with weak water stratification. The water depth showed a trend of becoming deeper, then shallower, and then deeper. The paleoclimate in the West Lishui Sag was warm on the whole. However, the content of Sr became smaller after later deposition, so the calculated paleowater temperature was higher. In addition, oxygen isotopes were affected by diagenesis, resulting in a negative oxygen isotope value. The paleoproductivity was low, and the hydrocarbon generation potential was poor. The content of nutrient elements mainly came from terrigenous input rather than biological origin, and terrigenous intrusion characteristics gradually increased from E1y to E1m2. The study also shows that paleoproductivity was affected by the paleoclimate and paleowater depth. Warm and humid climate and deep water body were conducive to the accumulation of paleoproductivity.

Archaeological work began in 1928 at Yinxu (also known as Yin Ruins), the site of the capital of the late Shang Dynasty, and the continuous excavations have yielded the discovery of numerous remains and relics. The late Shang Dynasty was the zenith of China’s Bronze Age, and research on various aspects of Yinxu has gained attention among Chinese and international archaeologists. The layout of Yinxu, especially the water conservancy systems, has become a popular subject of research in recent years. Nevertheless, quantitative research is lacking in the existing literature. Using geographic information systems (GIS) allows such research to be carried out. This study used the hydrology and density analysis modules of ArcGIS software to study the water system and urban layout of Yinxu quantitatively. The results show that the water conservancy system altered the surface runoff pattern of the city and effectively harnessed limited local water resources. The system, centered on artificial channels, was built during the Second Phase of Yinxu, largely because of climate change and the city’s expansion. Its construction, in turn, profoundly affected the layout of the city. Dwellings and handicraft workshops clustered around areas with abundant water resources; together with the Huan River, the large-scale water conservancy facilities acted as partitions that practically isolated the “central zone”, creating a wall-less defense system that differs from other capital cities in the Bronze Age of China.

Natural gas generation is the result of organic matter degradation under the effects of biodegradation and thermal degradation. Early Cambrian black shales in the Upper Yangtze Region are rich in organic matter and have shown great shale gas potentiality in recent years. Nevertheless, the enrichment mechanism and distribution of organic matter in these black shales between different sedimentary settings, such as intra-platform basin, slope, and deep basin, are still poorly understood. In this paper, based mainly on elemental geochemistry, a comprehensive study of the marine redox conditions, primary productivity, sedimentation rate, terrigenous input, hydrothermal activity, and water mass restrictions was conducted on the Early Cambrian Niutitang black shale in the Upper Yangtze Region. Our data showed that an intra-platform basin received a higher terrigenous input and that it deposited under more restricted conditions than the slope and deep basin settings. The primary productivity in the slope and deep basin settings was higher than that in the intra-platform basin setting. In the intra-platform basin, the productivity increased from its inner part to its margin. For the slope and deep basin settings, the high paleoproductivity generated large amounts of organic matter and its preservation was synergistically affected by the redox conditions. In contrast to the slope and deep basin, the preservation of organic matter in the inner part of the intra-platform basin was mainly controlled by redox conditions because the paleoproductivity in it was much lower than in the slope and deep basin settings. The intra-platform basin margin was the most favorable area for accumulating organic matter.

The Chaoyang profile represents a rare multi-period, continuous and complete sequence of aeolian paleo-deposits with a stable sedimentary origin and multi-stage paleoclimatic cycles. Benchmark profiles including soil types at different pedogenic stages can be used for the recognition and classification of paleosols and paleoclimate reconstruction. The loess–paleosol sequence benchmark profile (LBP) is also helpful in comparing the results of paleoenvironment reconstruction from different ecological regions. In this study, a loess–paleosol profile derived from thick loess in Chaoyang city of Liaoning province, Northeast China, was investigated as a well-preserved LBP that included various paleosol types. To determine the nature and origin of the Chaoyang profile, the geographic, stratigraphic and morphological characteristics were described in the field. Bulk samples from 42 horizons were collected for chemical and physical analysis, and sub-sampling of 946 samples at 2 cm intervals from the surface to the bottom were taken to measure grain size distributions and magnetic susceptibility. Results showed that the 19.85 m thick loess–paleosol profile had been continuously deposited since 423 ka BP. The upper part (0–195 cm), or UPP, was predominantly of aeolian loess deposition origin but was mixed with water-reworked materials from a nearby secondary loess source. The middle part (195–228 cm), or MIP, was also indirectly affected by the water-reworking process through the leaching of materials from the overlying UPP. The lower part (228–1985 cm), or LOP, was characterized by four reddish stratigraphic layers interbedded with five yellowish ones, indicating several types of paleosols developed under different ecological environments. The multi-stage paleoclimatic cycles as evidenced by morphological and physical characteristics as well as age dating and magnetic susceptibility correlated well with the Lingtai section and LR04 benthic δ18O. Because of these attributes, the Chaoyang profile can be deemed as a benchmark loess–paleosol profile for the recognition and classification of paleosols and paleoclimate reconstruction in Northeast China. The differences in morphological and physical properties between paleosols and loess suggest different soil fertility and agronomic properties and need further studies to assess their functionality with climate fluctuation.

This study is aimed at comparing ostracod assemblages during the Eocene-Oligocene transition that were identified in the Paleogene succession at twenty-two previously studied locations across the seven geographical regions of Turkey. The formations deposited in the Eocene-Oligocene and the paleogeographic distribution and paleoenvironmental properties of the ostracods that were identified in these formations were investigated in the following different geographical regions of Turkey: the Aegean (Denizli), the Eastern Mediterranean (Mut, Karsantı Baseni), Southeastern Anatolia (Adıyaman), Eastern Anatolia (Malatya-Darende, Elazığ), Central Anatolia (Karaman, Ulukışla, Sivas, Ankara), Northern Anatolia (Batı Pontidler/Kastamonu) and Northwestern Anatolia (İstanbul, Çatalca/GD Trakya, Kırklareli, Tekirdağ). The ostracod biozones in the acme-zone category were studied in these geographical regions. The zones were identified and chosen by successions or rock assemblages. The study revealed that the Eocene-Oligocene ostracod species demonstrated lacustrine, lagoonal, lagoon-littoral, epineritic, epineritic-infraneritic and infraneritic-bathyal environmental conditions. It was observed that, especially in the Aegean, Northwestern Anatolia and Southern Anatolia/Eastern Mediterranean regions, marl and silty sandstone in the upper and bottom levels of the Oligocene, in which coal settlement is observed, were usually deposited in lagoons containing ostracods. Furthermore, in the studied regions the co-occurrence of ostracod species living in maritime conditions with ostracod species living in lagoonal conditions can be explained by sea-related excessive shoaling in the basins. In Turkey, judging from environmental properties of the ostracod species, the transgression of the sea declined from northeast to northwest during the Eocene–Oligocene. © 2018, Pleiades Publishing, Ltd.

The Chiba composite section (CbCS) in the Kokumoto Formation, Kazusa Group, central Japan is a thick and continuous marine succession that straddles the Lower–Middle Pleistocene boundary and the well-recognized Matuyama–Brunhes paleomagnetic polarity boundary. Although recent studies extensively investigated the CbCS, its chemostratigraphy, particularly around the Lower–Middle Pleistocene boundary, is poorly understood. Therefore, in this study, we performed multiproxy sedimentological and geochemical analyses of the CbCS, including the Chiba section, which is the Global Boundary Stratotype Section and Point for defining the base of the Middle Pleistocene Subseries. The aim of these analyses is to establish the high-resolution chemostratigraphy and to reconstruct the paleoenvironments of its sedimentary basin in detail. We used the K/Ti ratio as a broad proxy for the clastic material grain size of the sediments. Although the K/Ti ratio generally varies throughout the studied interval, the K/Ti ratio especially during Marine Isotope Stage (MIS) 19a shows a variation pattern like those of the foraminiferal oxygen isotope (δ18O) records. The records of the C/N ratio of bulk samples and carbon isotope ratio of the organic carbon (δ13Corg) suggest that the organic matter in the CbCS sediments during MIS 19c mostly originated from marine plankton, whereas the organic matter during MIS 18 and 19a was characterized by a mixture of marine plankton and terrestrial plants. These records are clearly indicative of changes in mixing ratio of marine vs. terrestrial organic matter in association with glacial–interglacial cycles from the late MIS 20 to the early MIS 18. In addition, we calculated the mass accumulation rates (MARs) of organic carbon, biogenic carbonate, and terrigenous material for quantitative interpretations on the paleoenvironmental changes. MAR calculations revealed that the contribution of marine organic carbon relative to terrestrial organic carbon increased during MIS 19c, and that the contribution of the terrigenous material relative to biogenic carbonate decreased during MIS 19c. Furthermore, we observed relatively large variations in the total organic carbon and total nitrogen contents during MIS 19a. These variations were probably caused by the relative decrease in bottom-water oxygen level, which is also supported by our trace-fossil data, although it is not certain whether the increase in organic-carbon flux at ~ 760 ka was due to the synchronous increase in biogenic productivity in surface water. Such a relative decrease in bottom-water oxygen level was partly due to the increased ocean stratification because of the northward displacement of the Kuroshio Extension Front.

The eastern China coastal plain is an ideal area for studying the human–environment interaction during the Neolithic period as there are multiple Neolithic sites in this area. Located in the Ningshao Coastal Plain of the south bank of Hangzhou Bay in eastern China, the Hejia Site is part of the late Hemudu Culture sites and includes the late Hemudu Culture, the Liangzhu Culture, and the Qianshanyang Culture. Based on palynology, charcoal, X-ray fluorescence (XRF), and magnetic susceptibility (χ), combined with accelerator mass spectrometry 14C dating and analysis of the archaeological cultural layers, we explored the paleoenvironmental evolution and human activities at the Hejia Site. 1) Pollen records suggest that the vegetation type was evergreen and deciduous broad-leaved mixed forest during the Middle Holocene. Cr/Cu and low-frequency magnetic susceptibility (χlf) reveal that the climate underwent through warm and wet (Hemudu Culture Period IV)–cool and dry (Liangzhu Culture Period)–warm and wet (Qianshanyang Culture Period) periods. 2) During the Middle Holocene, the intensity of human activities, related to the transformation of the natural environment, increased obviously. The increasing Poaceae pollen (>37 μm) indicates that the ability of prehistoric humans in managing crop fields gradually increased from the late Hemudu Culture Period to the Liangzhu Culture Period. The charcoal concentration results suggest that the occurrence of high-intensity fire events during the late Hemudu Culture Period might be caused by the slash-and-burn operation, while those that occurred during the middle Liangzhu Culture Period might be caused by the increasing fire demand owing to the greater ancestors’ lives and production activities in the Liangzhu Culture Period.

The Late Ordovician Mass Extinction wiped out 85% of animal species in two phases (LOME1 and LOME2). The kill mechanisms for the extinction phases are debated, but deteriorating climate and the expansion of marine anoxia appear to have been important factors. Nevertheless, the spatial extent and intensity of marine anoxia and its temporal relationship with the extinctions are not well understood. Here, we review existing global paleoredox proxy data based on molybdenum (Mo) and uranium (U) isotopes from four paleocontinents combined with new Mo isotope data from Dob's Linn, Scotland. Individually, these sedimentary records demonstrate significant redox fluctuations, but our coupled dynamic oceanic mass balance model for the evolution of the marine Mo and U cycles reveals that globally expansive ocean anoxia is best constrained by δ238U in carbonates from Anticosti Island that record expansive anoxia during LOME2. In addition, we consider periodic sulfidic anoxia developing in well-ventilated parts of the shallow oceans (e.g. during warmer periods with greater solar insolation) to have produced temporarily high seawater δ98Mo values during LOME1 in accordance with trends to high values observed in the sedimentary records. In this view, oceanic oxygen loss had a causal role during both extinction phases in the Late Ordovician.

[EN] The motillas are the first settlements in La Mancha during the Bronze Age. They are preferably positioned in the floodplain or the riverbed of the main rivers that cross La Mancha Plain. Researches in the motilla of Azuer (Daimiel, Ciudad Real), revealed the existence of a well (around 18 m depth) inside the fortified complex. The well object could be the calcareous levels of the Pliocene Mancha Occidental regional aquifer. It could be the Europe´s oldest groundwater exploitation system. New geological and hydrogeological investigations obtain relevant advances: all the motillas have a groundwater reservoir that could be exploited under extreme climatic conditions, by a dug well made with prehistoric methods. This confirms the hypothesis of de Motillas Culture development in during an extreme dry period, and groundwater catchment like a decisive factor., [ES] Los yacimientos arqueológicos conocidos como motillas constituyen los primeros poblamientos en la región natural de La Mancha en la Edad de Bronce. Se sitúan en la llanura de inundación o en el cauce de los principales ríos que atraviesan la Llanura Manchega. Los trabajos de investigación llevados a cabo en la motilla del Azuer (Daimiel, Ciudad Real), determinan la existencia de un pozo en el interior del recinto fortificado, de al menos 18 metros de profundidad, que podrían alcanzar los niveles calizos que forman el acuífero superior de la llanura Manchega, de extensión regional. Se considera el sistema de aprovechamiento de las aguas subterráneas más antiguo de Europa. El estudio de la geología e hidrogeología de la Mancha y las nuevas investigaciones llevadas a cabo en otras motillas, han permitido confirmar la existencia de niveles o formaciones en el subsuelo capaces de disponer de recurso de agua suficiente en condiciones de extrema sequía, a profundidad y condiciones asequibles para la época. Se confirma la viabilidad de la hipótesis de la existencia de pozos de aprovechamiento de agua en el interior de las motillas, ante un escenario climatológico de extrema aridez

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:20:53Z No. of bitstreams: 0 Made available in DSpace on 2014-05-27T11:20:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-09-01 The Lagoa Dourada is a circular-shaped pond formed on the Furnas Formation (Devonian of the Paraná Basin), filled by late Pleistocene - Holocene sediments. It lies in the hydrographic basin of the Guabiroba River, a tributary of the Tibagi River situated in the Campos Gerais region of the State of Paraná, southern Brazil. The pond is about 200 m in diameter and the maximum water depth is 5.4 m. Geological, chemical, textural and mineralogical studies on a core sample of the sediments collected from the Lagoa Dourada, 12.2 m thick, was obtained for investigations of paleoenvironmental changes as well as to provide additional data to support previous reconstructions based on palynomorphs and diatoms. Within the period recorded in the core, the pond has been filled by sandy material introduced by springs at the northern edge of the pond as well as by muddy material brought in by floodwaters of the Guabiroba River. Thus, the sandy layers could be interpreted as evidence of drier climates with consequent diminution of fluvial overflow, but with maintenance of the sandy deposits coming from springs. The occurrence of euhedral pyrite in the sediments, locally associated with gypsum, may indicate periods of increase in the organic matter content or an increase in the water salinity, what could be related to greater evaporation under drier paleoclimate regimes. Three cycles defined by an increase in the total carbon content of the sediments of the pond were observed. These cycles seem to correspond to an increase in the isotope ratio 13C/12C (δ13C). Several hypotheses can be suggested to explain the presence of these cycles, including the alternation of wetter or drier climatic phases. The convergence of the sedimentological data obtained during this study with previous microfossil paleoclimatic (pollens and diatoms) indicators and radiocarbon dating suggests that a drier paleoclimatic phase occurred around 8720±150 years B.P. The evidence for a second drier phase in more recent times is less consistent. This subsequent phase could correspond to the drier phase in southern and southeastern Brazil between 5000 and 3000 years B.P. as suggested by other paleoclimatic studies. UEPG-Univ. Estadual de Ponta Grossa, Paraná IGUSP-Inst. de Geociencias du USP, São Paulo CENA-USP-Ctr.Estud.Nucleares Agric., Piracicaba UNESP-Univ. Estadual Paulista, São José do Rio Preto UNESP-Univ. Estadual Paulista, São José do Rio Preto

Frontiers in Earth Science 9, 1-17 (2021). doi:10.3389/feart.2021.599986, Published by Frontiers Media, Lausanne