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Shark teeth from representatives of four families, including Lamnidae, Hemigaleidae, Carcharhinidae and Sphyrnidae belonging to five genera, namely Isurus, Lamna, Hemipristis, Carcharhinus and Sphyrna, were recorded and documented for the first time from the South Garo Hills District of Meghalaya from the Baghmara and Chengapara formations of the Garo Group of rocks of Oligo-Miocene age. They show close affinity and similarities to the Miocene shark tooth assemblages recorded from the Baripada beds of Orissa and the Surma basin of Mizoram. These selachian assemblages from South Garo Hills point to a shallow marine, nearshore coastal environment well connected to the open sea. Thus, the present study provides new insights on the palaeodiversity and palaeoenvironmental setup of the Miocene sediments of South Garo Hills of Meghalaya and also enhances the existing knowledge of chondrichthyan diversity in India during the Miocene time. [ABSTRACT FROM AUTHOR]

The shells of freshwater mussels, commonly found at archaeological sites associated with the Kodjadermen-Gumelnița-Karanovo VI human groups (5th millennium BCE, Romania and Bulgaria), were a significant dietary component for this population. The organic matrix of these ancient shells is often well-preserved and can be analysed using stable isotopes. This study establishes the empirical relationship between the isotopic composition of the acid-insoluble shell organic matrix (AIM) and the soft tissues of modern Unio tumidus. A quality criterion for AIM (C:N ratio 3.6 (3.3–<3.8)) was defined, and isotopic offsets (Δ15NAIM-defatted body = +0.95‰, Δ13CAIM-defatted body = +0.93‰ for soft tissues; Δ15NAIM-muscle = +1.7‰, Δ13CAIM-muscle = +0.3‰ for the adductor muscle) were determined. Our data suggest that the Gumelnița mussels were omnivorous, with a similar trophic level to carp and pond turtles, sourced from diverse water bodies (rivers, lakes ...) based on δ13C values. [ABSTRACT FROM AUTHOR]

Low‐lying islands in tropical regions are vulnerable to near‐term sea‐level rise and hurricane‐induced flooding, with substantial human impact. These risks motivate researchers to elucidate the processes and timescales involved in the formation, growth and stabilization of coastlines through the study of Holocene shoreline dynamics. Little Ambergris Cay (Turks and Caicos Islands) is a low‐lying carbonate island that provides a case study in the nucleation and growth of such islands. This study investigates the sedimentology and radiocarbon chronology of the island's lithified sediments to develop a model for its history. The island's lithified rim encloses a tidal swamp populated by microbial mats and mangroves. Preliminary radiocarbon data supported a long‐standing inference that the island is Holocene in age. This study integrates petrographic, sedimentological and new radiocarbon data to quantify the age of the island and develop a model for its evolution. Results indicate that the ages of most lithified sediments on the island are <1000 cal yr bp, and the generation and lithification of carbonate sediment in this system supports coastline growth of at least 5 cm/year. The lithification of anthropogenic detritus was documented, consistent with other evidence that in recent centuries the lithified rim has grown by rates up to tens of centimetres per year. A unit of mid‐Holocene age was identified and correlated with a similar unit of early transgressive aeolianite described from San Salvador, The Bahamas. It is proposed that this antecedent feature played an important role in the nucleation and formation of the modern island. Results extend an established Bahamian stratigraphic framework to the south‐western extreme of the Lucayan archipelago, and highlight the dynamism of carbonate shorelines, which should inform forward‐looking mitigation strategies to increase coastal resiliency to sea‐level rise. These results inform interpretation of the palaeoenvironmental record of carbonate environments, underscoring their geologically rapid pace of lithification. [ABSTRACT FROM AUTHOR]

Understanding the stable hydrogen isotope (δ2H) composition and fractionation in lipid biomolecules of primary producers, such as terrestrial and aquatic plants, is crucial for deciphering past environmental conditions, as well as applying compound-specific stable isotope analysis for the study of metabolic and ecological processes. We conducted a new tracer experiment to explore the δ2H composition of algal fatty acid biomarkers, focusing on freshwater algae, which form the base of aquatic food webs. We selected a range of algal species widely found in freshwater ecosystems and cultivated them under controlled conditions. First, we added 2H2O to ambient water as a tracer to investigate the net hydrogen isotope fractionation during algal lipid synthesis at isotopic equilibrium, which is particularly informative for paleo-geochemical studies. Then, we conducted kinetic experiments to quantify the time needed for algal fatty acids to achieve isotopic steady-state conditions in response to the change in ambient water δ2H values. Our findings revealed substantial variability in hydrogen isotope fractionation among different algal taxa and various fatty acids. Based on taxa, different fatty acids exhibited faster integration of water hydrogen than others, but they were not necessarily in the order of the biosynthetic pathway. This experiment underscores the complexity of hydrogen isotope fractionation and the requirement for controlled laboratory studies to properly apply compound-specific stable H isotope analysis techniques in ecological and paleo-environmental studies. [ABSTRACT FROM AUTHOR]

The Greenland Ice Sheet is highly sensitive to climate change, leading to significant retreat along its edges. This rapid ice loss contributes to rising sea levels and impacts the Earth's climate stability. Understanding the extent of recent glacier retreat is crucial in order to determine if it is unprecedented or within ranges of natural variability. Palaeoenvironmental studies aim to identify past glacial phases and landscape changes using advanced dating methods such as cosmic ray exposure (CRE) dating. In NE Greenland, CRE dating has helped establish the timing of glacial oscillations, yet a comprehensive understanding of glacial fluctuations during specific periods still needs to be developed. This study aims to chronologically constrain the postglacial landscape evolution of two NE Greenland valleys from the Young Sund–Tyrolerfjord area (74°N, 20–25°E) from the onset of deglaciation and throughout the Holocene to better understand glacial and postglacial changes. The chronological framework relies on 27 10Be cosmic‐ray exposure ages that constrain our interpretation of the geomorphological features in both valleys. Inconsistencies were observed in the ages dataset, highlighting potential bias associated with nuclide inheritance and post‐glacial dynamics. Despite limitations, the CRE results confirm the general pattern observed in NE Greenland: (i) major deglaciation and disconnection of glaciers from the main glacial systems during the Lateglacial and Early Holocene with a rapid but not homogeneous deglaciation within the range from ~14.3 to 11.9 ka; (ii) no evidence of glacial activity during the Middle Holocene, probably associated with the withdrawn position of the ice masses’ fronts; and (iii) glacier expansion during the Late Holocene, with a Little Ice Age advance as the last significant period of glacial regrowth. [ABSTRACT FROM AUTHOR]

The alluvial filling of the middle basin of the Drâa River (southeastern Morocco) has recorded hydrogeomorphological responses to environmental changes. A systematic study of the Holocene fluvial terraces along an upstream-downstream section of about a hundred kilometers, combined with a sedimentary multiproxy study, was carried out on the alluvial archives of the Drâa's river. The stratigraphic field studies, combined with granulometric and geochemical X-ray Fluorescence analyses and radiocarbon dating, enable us to propose, for the first time, a reconstruction of the major stages in the morpho-hydrodynamic and paleo-environmental evolution of the middle Drâa river over the past 3500 years. Our results highlight six morpho-hydrodynamic and paleoenvironmental phases. Between 3500–2700 and 1800–1600 cal BP, the Drâa river was highly active, associated with torrential activity, reflecting arid climatic conditions. The lack of sedimentary record observed between 2800 and 2350 cal BP points either to a phase of erosion, or to a minimal and discontinuous activity that left no traces in the studied archives. The periods 2350–1800 (Roman Warm Period) and 1600–550 cal BP (Medieval Climate Anomaly) are characterized by strong fine and more regular alluviation punctuated by episodes of low energy of the Drâa floodplain, sometimes favoring fluviosols development that showed similar characteristics in the three outcrops studied. Finally, from 550 cal BP the fluvial records generally shows signs of anthropization, marked by the formation of anthrosols characteristic of fluvial oasis construction, and associated with the presence of ceramics and hearths, in which eolization features are frequent. The comparison of Drâa evolution in a broader paleohydrological and climatic context, integrating other Moroccan studies and regional data, shows solid connection with the river, lakes, and marine archives from the southern Mediterranean to the Western Sahelian steppe zones, revealing a clear response of this large hydrosystem to regional climatic variations. [ABSTRACT FROM AUTHOR]

The Ili‐Balkhash region in southeastern Kazakhstan hosts morphologically diverse dormant desert dune fields and presents an interesting opportunity for geomorphological and palaeoenvironmental studies. Because the morphology of aeolian dunes is primarily driven by wind dynamics, the dormant dunes in the study area may reflect past wind conditions. We assess their concurrence with modern ERA5 wind data to test whether there has been a change in wind regime since the dunes' last phase of activity. Our approach includes dune mapping, the quantification of dune orientations, the modelling of modern bedform orientations, and optically stimulated luminescence (OSL) dating for temporal context. The centrepiece of our methodological contribution is a novel semi‐automated mapping workflow using geographic object‐based image analysis (GEOBIA) and machine learning (ML) on Sentinel‐2 satellite imagery. Within the scope of a case study, we map dune fields in the Ili‐Balkhash region and quantify dune orientations. We further apply the maximum gross bedform‐normal transport (MGBNT) concept to model bedform orientations matching modern wind regimes for each of the sites. We find that strong winds show better alignment with observed dune orientations than wind regimes comprising all wind speeds. Furthermore, bedform orientations in some of our study sites, namely those that are located in the open plain southeast of Lake Balkhash, do not reflect modern winds. The divergence between dune orientations and wind regime suggests changes in local wind dynamics since the dune fields' last phase of activity. [ABSTRACT FROM AUTHOR]

The paleoenvironmental evolution of the Abrolhos Depression (AD) on the southern Abrolhos Shelf during the global post-Last Glacial Maximum (LGM) transgression is investigated through benthic foraminifera analysis. Downcore sediment samples (core DA03A-5B) collected at a depth of 63 m provide insights into the formation and paleoenvironmental variations of AD over the past 18 kyr BP. The core is divided into four biofacies based on foraminifera assemblages. At the base, the presence of carbonate concretions indicates a karstic surface, marking the initiation of the paleolagoon formation at approximately 13 kyr BP with low density of foraminifera, where species such as Elphidium sp. and Hanzawaia boueana (EH Biofacies) were more abundant. During the Younger Dryas (YD) (12.8–12.5 kyr BP), the AD exhibits two distinct phases: an initially confined lagoon environment with reduced circulation characterized by the dominance of the species Ammonia tepida (At Biofacies), followed by increased circulation characterized by higher density, richness, and diversity of benthic foraminifera. The end of the YD is identified by a significant biofacies change, indicative of a shallow marine environment, where the dominant species were A. tepida and Elphidium excavatum (AE Biofacies), supported by sedimentological and geochemical proxies. This paleoenvironmental shift is associated with Meltwater Pulse (MWP) -1B, suggesting a connection to a shallow marine environment. As sea levels continue to rise, the AD transitions into an open marine setting. However, around 8 kyr BP, a change occurs with the absence of A. tepida and the occurrence of planktonic and other benthic foraminifera typical of the outer shelf, indicating depths greater than 50 m (HQ Biofacies). The findings highlight the complex interplay between climate fluctuations, sea-level changes, and the formation of coastal environments during the LGM transgression. This study contributes to our understanding of paleoenvironmental dynamics, adding valuable insights to the evolutionary history of AD. The results emphasize the importance of integrating benthic foraminifera analysis, radiocarbon dating, and geochemical proxies to reconstruct paleoenvironments accurately. Overall, this research enhances our knowledge of global continental shelf evolution during the post-LGM transgression and provides valuable information for future paleoenvironmental studies. [ABSTRACT FROM AUTHOR]

Key message: This article presents ring width chronologies derived from samples extracted from historical timber buildings in the French central Pyrenees. Two chronologies for fir (Abies alba Mill.) were dated for two periods: 1446–1655 and 1679–1952 AD. These chronologies are suitable for dendroarchaeological and paleoenvironmental studies, or for reconstructing past climates. Dataset access is at https://doi.org/10.48579/PRO/KH6HPC and associated metadata at https://metadata-afs.nancy.inra.fr/geonetwork/srv/fre/catalog.search#/metadata/edba546e-3769-4f06-959b-f0d8db7fbcdb. [ABSTRACT FROM AUTHOR]

Numerous Priabonian and Oligocene tuff layers within the Eastern and Central Europe Paratethys and Tethyan sedimentary basins attest for extensive volcanic activity during that period. However, the sources of these eruptions are completely unknown. Using precise radioisotopic dating, along with their stratigraphic relationships, we correlate some of these tuff layers with Rupelian eruptions from the Rhodope Massif, South Bulgaria. Three major silicic eruptions of ignimbrites and ash falls, namely Dazhdovnitsa, Borovitsa and Perelik, with ages of 33.2 Ma, 32.8 Ma and 31.6 Ma, respectively, have been identified in the Rhodope Massif. The ejected tephra was dispersed over more than 1,000,000 km2 and the combined estimated volume of thousands cubic kilometers, which marks this period as one of the most voluminous sequence of volcanic eruptions/explosions in Europe in the Rupelian Stage. The areal coverage and estimated volumes meet the requirements for volcanic supereruptions and the wide geographic occurrence of the products can be used as stratigraphic isochronous marker horizons for correlating, dating, and synchronizing deposits and events in geologic and paleoenvironmental studies. Further, the volcanic products were deposited during the early Rupelian anoxic Paratethys events and we explore the possible influence of volcanic eruptions on the process of anoxia. [ABSTRACT FROM AUTHOR]

The history of fires in southwestern Tuscany (Italy), from the Colline Metallifere to the coast of northern Maremma, is presented with an observational perspective at local and regional scale. The area was studied as part of the nEU-Med project, which investigates resources management, agricultural practices and political strategies in two coastal plains, the Cornia and Pecora valleys, between the 7th and 12th centuries AD. Four cores, selected for palaeoenvironmental studies, were analysed for microcharcoals (C3 and C7 - Cornia Valley, ∼last 7500 years; P3 and P4 - Pecora Valley, ∼last 3200 years). Microscopic charcoal particles are ubiquitous and particularly high in the most recent pollen zone of the diagrams: most records belong to the 10–50 μm size class (>90%), followed by the 50–125 μm size class (<7%) and the rest are records of size >125 μm. The last size class includes large microcharcoals indicating local fires. Several potential fire activity increases (PFAIs) are visible as peaks in the diagrams. In the Cornia Valley, ancient phases of local fires were recorded at ∼5600 BC; not strictly local fires were scattered in the valley at ∼4600 BC, ∼3500 BC, and until ∼400-1450 AD, when the peaks testify to the spread of fires with increasing human activity. In the Pecora Valley, scattered local fires are observed at ∼900 BC, between ∼300 BC and ∼50 BC, and in the later phases from ∼400 AD to ∼1050 AD. Therefore, the increase in fires is visible in the last millennium in both valleys. Fire was probably used to open the landscape, as fluctuations of pollen curves of mixed oakwood (mainly deciduous Quercus) and Erica suggest. The extensive presence of shrubby heather vegetation testifies to the occurrence of repeated fires. In the Cornia Valley, besides oaks, the main fuel source were Corylus avellana and Ostrya carpinifolia/Carpinus orientalis. In the Pecora Valley, cores show a synchronous increase in AP and NAP pyrophytes until ∼400-500 AD, followed by a decrease in AP pyrophytes. Considering forest dynamics, a too short return time for fires affects the biodiversity of woody plants, as woods could not fully recover and several tree species may not have reach sexual maturity, resulting in less sprouting and recolonization. In these valleys, the recovery of large-sized microcharcoals, the presence of heather shrub vegetation, and the trend of AP/NAP pyrophytes suggest that fires have increased significantly in the last ∼1200 years (∼800-1400 AD). [ABSTRACT FROM AUTHOR]

Cuttings and logs from four boreholes in the Mediterranean Sea, offshore the northwestern side of the Nile Delta, Egypt (30°00'–30°24' N, 31°18'–31°30' E), were examined lithostratigraphically, biostratigraphically and paleoenvironmentally. Five planktonic foraminiferal zones were determined assigning the studied boreholes to be late Miocene-Early Pliocene in age. These zones are Globorotalia mediteraneaneana Zone Sphaeroidinellopsis seminulina Zone, Globorotalia margaritae margaritae Zone, Globorotalia puncticulata Zone and Globorotalia inflate. Studying benthonic foraminifera indicated a general shallowing upward trend in all boreholes and tracking the distribution of the foraminiferal assemblages by counting the total number of foraminifera and planktic/benthic ratios provide a history of the progression of deltaic facies with secondary cycles of sea-level change. [ABSTRACT FROM AUTHOR]

Fecal sterols are traditionally ascribed as important biomarkers for animal excrement, and have been widely used to identify the source of organic matter and to reconstruct paleoecological changes in Antarctic terrestrial, aquatic, and marine ecosystems. However, the in situ microbial hydrogenation of cholesterol to coprostanol could have significance as a proxy to infer paleoenvironmental studies in Antarctica, particularly in anoxic sediment. Here, we report that abundant coprostanol, which was traditionally deemed as a biomarker for human sewage contamination, was found in three anoxic sediment profiles (AC2, BI, and CH1), which were strongly influenced by animal excrement at North Victoria Land, western Ross Sea, Antarctica. Our results suggest that the high concentrations of coprostanol in these three sediment profiles were not due to animal excrement, since coprostanol is not present in penguin guano and is a minor component in seal excrement. Coprostanol/cholesterol and coprostanol/(coprostanol + cholestanol) ratios suggest that coprostanol in the sediment cores of AC2 and BI was primarily derived from bacterial hydrogenation of cholesterol introduced by penguin guano. Coprostanol in CH1 sediments is related to human sewage due to intensive research activities from 1968 to 2006 in this region. However, the low abundance of coprostanol and the ratios of coprostanol/cholesterol and coprostanol/(coprostanol + cholestanol) in a relatively oxidizing sediment core (IIL1) infer that coprostanol was likely contributed by seal settlement. Together with high-throughput sequencing of the 16S rRNA gene, the conversion of cholesterol to coprostanol by anaerobic bacteria (e.g., Eubacterium coprostanoligenes) could occur in anoxic aquatic systems. Our results suggest that the presence of coprostanol in Antarctic lacustrine sediment with anoxic conditions does not necessarily indicate seal activity and human waste as the microbial hydrogenation of cholesterol to coprostanol should also be considered. [ABSTRACT FROM AUTHOR]

The article focuses on intact stalked crinoids from the late Aptian of North East Spain, offering insights into the Mesozoic Marine Revolution in the Tethys. It provides a detailed description of the deposit and paleoenvironmental interpretation, including crinoid predation and preservation. It explores the fossilized remains preserved in a series of strata, analyzing the orientation and preservation states of crinoids to infer their behavior before death and burial.

Aim: Few palaeoenvironmental studies have been performed in Araucaria‐Nothofagus forests, which are highly vulnerable to ongoing threats from climate change and anthropogenic activities. The primary goal of this work is to reconstruct past environmental changes related to fire disturbances over the last 1800 years in Tolhuaca National Park (TNP), Chile. Location: TNP, Araucanian region (38.2°S; 71.8°W), Northwestern Patagonia, Chile. Taxa: Araucaria araucana (Araucariaceae), Nothofagus spp. (Nothofagaceae). Methods: We completed charcoal and pollen analyses to create two new palaeoecological records that span 1800 years. We compared the lake‐based reconstruction with the available local tree‐ring fire scar chronologies from the last 430 years. Using these data, we compute forest index changes, biomass burning trends and compare with estimates of archaeological radiocarbon density. We place our inferences with context of published regional palaeoclimatic proxies from the Patagonian‐Andean region. Results: Our results showed that fire activity was higher than present between 200 and 1500 CE, with peaks around 200–400 CE and 1100–1500 CE. Periods with high fire activity are associated with reduced forest cover, as Araucaria declined when mixed‐severity fire regime occurred for extended periods. Pollen assemblages suggested a shift from dry to wet climate conditions at 1500 CE, and from 1750 CE onward, the arrival of exotic species reflected the land‐use changes related to forest clearance and transhumance practices. Main Conclusions: The palaeoenvironmental reconstructions showed changes in vegetation, fire and climate over the past 1800 years in TNP. Wildfires have been the main disturbance process modifying the vegetation structure in the Araucaria and Nothofagus forests. Since 1750 CE intensive post‐Hispanic land‐use changes (forest clearances by fire and logging) took place in the study area, reducing the native vegetation cover. Climate variability, modulated by SAM‐like and ENSO‐like conditions, influenced the fire activity (availability and flammability of fuels), concomitantly with high archaeological density. The recent (after 2000 CE) increase of catastrophic wildfires may negatively affect the conservation strategies of Araucaria‐Nothofagus forests. [ABSTRACT FROM AUTHOR]

The Croatian Natural History Museum (CNHM) houses rich fossil collections from the Neogene deposits of Northern Croatia, comprising numerous scallops (Bivalvia: Pectinidae). During the Middle Miocene (Badenian = Langhian and early Serravallian), this region was located at the southwestern margin of the Central Paratethys. The value of the CNHM's historical collections has been presented through taxonomic revisions and biostratigraphic, paleoenvironmental and paleogeographic study. Methods included the cross-checking of specimens from museum boxes with all available published data, systematic revision of scallops, recording the abundance of each taxon, defining the preservation state of the specimens, measuring the morphometric elements and taking photographs of each specimen. After the conducted revision of 624 specimens, the number of registered taxa in the collections was reduced from 52 to 33, and their stratigraphic distribution has been updated. The species Lissochlamys excisa (Bronn, 1831) has been recorded for the first time at the southwestern part of the Central Paratethys. The southernmost Badenian record of Delectopecten vitreus (Gmelin, 1791) known so far has been described. Six types of pectinid habitats have been distinguished, based on the provided paleontological and lithological data, also estimating the scallops' abundance in each of them. Bioerosion and encrustation traces on scallops' shells represent an additional contribution to paleoecological studies. [ABSTRACT FROM AUTHOR]

A multidisciplinary study, including geomorphological, stratigraphic, paleontological and archaeological methods and techniques, allowed for a detailed exploration of coastal landforms and environments in front of the ancient city of Pompeii (southern Italy). The famous site of Pompeii sits on a small volcanic hill in the alluvial-coastal plain of the Sarno River, very close to the ancient paleoshoreline. When the Roman city was buried during the eruption of Vesuvius in 79 CE, pyroclastic fall and flow deposits covered the urban centres and ancient coastal landforms. In this study, 83 new boreholes were carried out up to a depth of 10 m. Some of them (15) were analysed for their sedimentological, stratigraphical and paleontological characterisation, in order to reconstruct the sedimentary environments in 79 CE. The data collected allow for new hypotheses to be formulated regarding the paleoshorelines, as well as the 79 CE coastal landforms and environments. In particular, litho-stratigraphic and fossil assemblages highlight the presence of shallow marine environments in a large back-ridge depression, named Masseria Curati, that is located just outside the city walls. This hypothesis opens new insights on the unknown location of the harbour of the Roman city. [ABSTRACT FROM AUTHOR]

Marine shale gas has emerged as a prominent unconventional petroleum resource in recent years, known for its abundant reserves and energy potential. Based on the database of geochemical, mineralogy and physical lab measurements, this study investigates the paleoenvironmental conditions and shale gas potential of the Carboniferous Dawuba and Cambrian Niutitang shales in the Upper Yangtze Platform, South China. Analysis of the paleoclimate and water conditions reveals that the Dawuba shale was deposited under a warm and arid climate with reducing conditions that favored organic matter (OM) preservation, transitioning towards marine conditions with increasing salinity. The Niutitang shale experienced a cooler, arid climate with prevalent saltwater and reducing conditions, also conducive to OM preservation. Both formations have reached the post-mature stage, displaying good to excellent source rock potential. The Dawuba shales are characterized by Type II2 kerogens, while the Niutitang shales predominantly contain Type I kerogens, indicating high gas generation potentials for both. The formations are composed of mixed and argillaceous shales, exhibiting ultra-low porosity and permeability but featuring development of dissolution pores, OM pores, and micro-fractures essential for gas storage. Comparative analysis shows the Dawuba shales have superior BETspecific surface areas, total pore volumes, and average pore diameters than the Niutitang shales. However, gas contents in both formations are relatively low, underscoring the necessity for further research on shale gas preservation conditions. The Qiannan Depression in Guizhou, particularly the Shangyuan and Zongdi areas of the Dawuba Formation, are identified as promising regions for shale gas exploration due to favorable geological characteristics. This study highlights the significant shale gas potential in the Upper Yangtze Platform and calls for focused research to optimize exploration and extraction efforts. [ABSTRACT FROM AUTHOR]

• This study summarizes all existing and unpublished data on the Late Triassic plant fossils in Guangdong. • Four regional assemblages have been distinguished in the Late Triassic by marine fossils such as ammonites and bivalves. • The Late Triassic climate in the Guangdong region was mainly warm and humid, either tropical or subtropical. • During the Late Triassic, central and northern Guangdong were located at similar latitude, along the southern coastline of the South China Block. Triassic-Jurassic deposits are well developed in Guangdong Province, South China. In particular, the Upper Triassic coal-bearing strata which alternate between marine and terrestrial deposits yield diverse and abundant fossil plants, ammonites and bivalves. These strata provide a significant reference for the study of palaeoenvironmental variations in the lower latitude regions. In this paper, we review the major progress on Late Triassic floral studies in this area. Specifically, we compare the regional plant assemblages from different fossil sites in central and northern Guangdong which have been dated with marine fauna. 155 species belonging to 56 genera of fossil plants have been reported so far in northern and central Guangdong. The Late Triassic floras in Guangdong are mainly composed of Bennettitales and ferns, followed by horsetails, seed ferns, cycads, ginkgos and conifers. In ascending order, four regional plant fossil assemblages can be recognized in the Late Triassic deposits, namely the Pachypteris - Lindleycladus Assemblage (Julian), the Pterophyllum - Baiera Assemblage (late Julian), the Clathropteris - Otozamites Assemblage (Tuvalian), and the Danaeopsis - Anomozamites Assemblage (Rhaetian). In general, the Late Triassic climate in the Guangdong region was mainly humid and warm and either tropical or subtropical. The fossil plants corroborate palaeomagnetic evidence that the central and northern Guangdong region was located at approximately the same latitude as it is today and formed the southern coastline of the South China Block during the Late Triassic. Palaeogeographically, the transgression started at the end of the Julian and the south coastal terrane consisted of a western bay, a peninsula and an eastern bay. During the regression period, post-Rhaetian, the bays evolved into a gulf coastal plain. [ABSTRACT FROM AUTHOR]

Inertinite, as an important and abundant maceral group in coal, is critical for the study of palaeowildfires and their roles in the Earth's ecosystems. Recently, there has been a significant amount of research on the relationship between palaeowildfire, palaeoclimate change and palaeovegetation evolution based on inertinite data. The reflectance of fusinite and semifusinite has been used to estimate the combustion temperature and type of palaeowildfires, and then to evaluate the combustion characteristics of different types of palaeowildfires. The relative abundance of inertinite can be used to estimate the atmospheric oxygen contents. The rapid development of artificial intelligence (AI) and online tools to search scientific databases has presented an opportunity for us to find, collect, arrange, and analyse data from the earliest to latest publications on inertinite. The data extraction tool Deep Shovel is used to collect and analyse global inertinite data from the Silurian to the Neogene. The software programs such as Gplates, ArcGIS pro and Tableau are then applied to model the relative abundance of inertinite over geological time, which can be correlated with other parameters such as atmospheric oxygen contents, plant evolution and palaeoclimate changes. The distribution of inertinite in coals varied over different geological periods, being typified by the "high inertinite content-high atmospheric oxygen level" period in the Permian and the "low inertinite content-low atmospheric oxygen level" period in the Cenozoic. This study has proposed a possible model of the positive and negative feedbacks between inertinite characteristics and palaeoenvironmental factors, and has revealed the exceptional role of inertinite in palaeoenvironmental studies. Future research on inertinite will be focused on the integrated study of organic petrology and organic geochemistry of inertinite, the big data-driven research on the temporal and spatial distribution of the global inertinite, the exploration of the functions of palaeowildfires in the Earth systems in different climatic backgrounds, and the study of modern wildfires to better predict the future frequency and intensity of wildfires due to climate changes. [ABSTRACT FROM AUTHOR]

The application of stable isotope analyses allows a diachronic characterisation of species habitat and feeding behaviour, information of utmost importance for zooarchaeological research. In South America, the former distribution of the guanaco (Lama guanicoe) encompassed a much larger territory than the current one. Within the Argentinean Great Chaco, only a small native population persists in Northwestern Córdoba province, Central Argentina, where it was once widely distributed. In this paper, we present the first set of dentin and collagen δ13C and δ15N values for this relict population (N = 18) along with archaeological data of guanaco specimens (N = 19) dated to the Middle and Late Holocene from the nearby Ongamira valley. Neither deciduous and permanent teeth nor males and females show marked differences within the modern samples. Both modern and archaeological guanaco δ13C values indicate a mixed diet of C3 and, to a lesser extent, C4 plants. Conversely, the δ15N values exhibit distinct signals between the Arid and the Mountain Chaco subregions. The diet breadth of the archaeological guanacos suggests the use of transitional or ecotonal environments, also reflected in the size of their isotopic niche as opposed to modern guanacos. Regarding the timing of the species retraction in the region, there is no evidence of a shift in its habitat during the period between ~4700 and 190014C years BP. We suggest their retraction probably occurred later than previously proposed in regional zooarchaeological models. [ABSTRACT FROM AUTHOR]

Copyright of Spanish Journal of Palaeontology is the property of Socieadad Espanola de Paleontologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Spanish Journal of Palaeontology is the property of Socieadad Espanola de Paleontologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Northeast China played an irreplaceable role in population migrations and cultural exchanges in East Asia during the Paleolithic. This paper collected 182 archaeological sites to analyse the characteristics of spatial-temporal variations of Paleolithic human activities in Northeast China, and explored the driving mechanisms behind these variations in combination with the paleoenvironmental and archaeological studies. During the Lower Paleolithic, constrained by the relatively cold-dry climate and blocked by the Songnen paleo-lake basin, the population was sparse and distributed only near 40° N at the southern end of Northeast China. Upon entering the Middle Paleolithic, as humans developed greater tolerance to cold climates and adopted more sophisticated survival strategies with the application of small lithic tools, their numbers increased and geographical distribution expanded northward to 45° N at the central region of Northeast China. The Upper Paleolithic saw a considerable increase in population and expansion across almost all of Northeast China except for the eastern Inner Mongolia Plateau. We speculated that 50 ka and 30 ka BP were two key points, both of which may be associated with a significant increase in the frequency of migrations and communications among humans, and the widespread popularity of highly mobile microblade technology, respectively. In addition, the environmental analysis of archaeological sites revealed a continuous spread of Paleolithic humans to areas with higher elevations, steeper slopes, and lower temperatures. Meanwhile, they were becoming less reliant on water resources and were more widely conducting activities in open-air areas, showing that the environmental adaptability had been continuously improving over time. This study can provide a reference for the reconstruction of the migration history of early humans in East Asia, and is also of great significance for a comprehensive understanding of the evolutionary process of early human-environment interactions. [ABSTRACT FROM AUTHOR]

This research was carried out in north-central Poland, which was occupied by the ice sheet of the Saalian (Marine Isotope Stage [MIS] 6) and Upper Stadial of the Weichselian (MIS 2) glaciation. The application of the anisotropy of magnetic susceptibility (AMS) method supported by a digital elevation model (DEM) analysis of the orientation of glacial landforms allowed for the reconstruction of ice-sheet extent and ice movement directions of these two Pleistocene glaciations. The research used an innovative method of collecting AMS till samples from the glacial plateau areas. Based on the research, it was found that during the general recession of the ice sheet of the Saalian glaciation, a previously undescribed glacial transgression occurred, characterized by a different direction of ice-sheet movement. On the basis of detailed geomorphological studies of the area of terminal moraines, previously described in fragments, the maximum extent of the ice sheet during the Weichselian glaciation was clarified. The recession of the ice sheet of the Weichselian glaciation from the area of north-central Poland took place in four regressive or transgressive–regressive stages with variable directions of ice-sheet movement. The results obtained indicate the great potential of the AMS method in paleoenvironmental studies of glaciated areas. [ABSTRACT FROM AUTHOR]

This multidisciplinary study aims to decipher the impact of ancient charcoal production on past and present‐day soils in the northern Vosges Mountains. Soil observations in the field and laboratory were complemented by charcoal and phytolith studies on large thin sections, molecular analyses of organic pollutants, and phytolith analysis on bulk samples. The complex technosol platform records an ancient natural soil sequence buried by a human‐made platform on which charcoal accumulated. The current upslope soil is an entic Podzol. Palaeoecological data collected in the buried soil are reliable owing to low bioactivity due to soil acidity. Podzolisation predated the platform construction. The presence of ashes induced low soil alkalisation developed in the charcoal hearth remains and appears to have generated the migration of subsequent iron/clay/organic bands throughout the platform sediment and the buried soil. Charcoal studied in thin sections revealed mainly Quercus and Fagus taxa. Phytolith studies suggest that a less dense or degraded forest preceded platform construction, probably due to former woodland coppicing or earlier disorganised wood gathering. The specific distribution of polycyclic aromatic hydrocarbons sorbed on charcoal has persisted in soils throughout centuries, but we have no evidence that charcoal‐making activities contributed to diffuse global pollution. [ABSTRACT FROM AUTHOR]

Changbaishan volcano (China/North Korea) is one of the most active and hazardous volcanic centers in Northeast Asia. Despite decades of intensive research, the eruption history of this stratovolcano remains poorly constrained. One of the major puzzles is the timing of the eruption that produced the Tianwen Yellow Pumice (TYP) deposit at the caldera rim. Here we identify a new cryptotephra layer in sediment core 13PT‐P4 from the East Sea. Grain‐specific major, minor, and trace element analyses of glass shards allow a clear correlation of this distal tephra to the proximal TYP deposit of Changbaishan. Age‐depth modeling using radiocarbon (14C) dates of sediment bulk organic fractions and other tephrochronological markers from the sediment sequence constraints the age of the cryptotephra and thus the TYP eruption to 29,948–29,625 cal yr BP (95.4% confidence interval). Our findings lead to a revision of the history of Changbaishan explosive activity, and show that the volcano has been particularly active during ca. 51–24 ka BP in the last 100 ka. Using high resolution palaeo‐proxy records, we find the TYP tephra almost coeval with regional to hemispheric‐scale climatic changes known as Heinrich Event 3 (H3). With its precise age determination and wide geographic dispersion, the tephra offers a key isochron for dating records of past climatic changes and addressing the phasing relationships in environmental response to H3 across East Asia. Plain Language Summary: Improving the knowledge of past volcanism is critical for volcanic hazard mitigation. Changbaishan volcano is one of the most dangerous volcanic centers in Northeast Asia, but its eruption history is not clearly understood. A classic example is the eruption that produced the magnificent Tianwen Yellow Pumice (TYP) deposited at the crater rim. Previous studies suggested a range of very different ages for this major eruption. In this study we trace its volcanic ash into a marine sediment core from the East Sea. By radiocarbon age‐depth modeling we are able to say with a high level of certainty that the eruption occurred sometime between 29,948 and 29,625 cal yr BP. The new results demonstrate the dispersal potential of ash from the eruption and shed light on the history and frequency of Changbaishan explosive activity. In addition, the TYP eruption is found to coincide with hemispheric‐scale and regional environmental changes. As a consequence, the volcanic ash can be used as a key time mark for dating sediment sequences and for investigating past environmental changes in East Asia. Our study also demonstrates the potential of using distal volcanic ash in reconstructing past explosive volcanism. Key Points: Timing of the Changbaishan Tianwen Yellow Pumice (TYP) eruption is resolved through proximal‐distal tephra correlation and radiocarbon age‐depth modelingEruption history of the Changbaishan volcano is revised, and dispersal potential of the TYP tephra is shown for the first timeA demonstration that the TYP tephra, as a regional marker, has great potential for sediment sequence‐based palaeoenvironmental studies [ABSTRACT FROM AUTHOR]

Ichnofossils have been defined for the first time from the rocks exposed along the Katilu Khad section, Dunera, Punjab (India) of Miocene succession. Eight ichnotaxa with 12 ichnospecies have been recorded, including Arenicolites isp., Beaconites coronus, Helminthopsis tenuis, Lockeia siliquaria, Palaeophycus tubularis, Palaeophycus isp., Planolites annularis, P. beverleyensis, Skolithos linearis, Taenidium barretti, T. cameronensis, and T. serpentinum. The present ichnofossil assemblages are recognised by two ichnofacies – Scoyenia and Mermia. Scoyenia ichnofacies is typified by less diversity but a high abundance of meniscate burrow (Taenidium and Beaconites), whereas Mermia ichnofacies shows high diversity grazing and feeding traces with low abundance. These ichnofacies indicate well-oxygenated, low-energy deposition exposed to air and represent the fluvial environment. [ABSTRACT FROM AUTHOR]

This study examines the sedimentary cycles of the so-called "post-nappe" Miocene in the Tizi Ouzou basin. The objective is to highlight facies transitions that signify changes in depositional environment conditions, facilitating the reconstruction of paleoenvironmental evolution. Concurrently, the study aims to refine the age determination of the studied formations by relying on the content of planktonic foraminifera. Furthermore, determining the paleoenvironments during this specific period will provide a better understanding of the events characterizing this phase in the geological history of the Tizi Ouzou Basin. This contribution is crucial for a global understanding of, among other things, the offshore basin, which is the subject of numerous academic studies and petroleum exploration efforts. The post-nappe Miocene (post-thrust Miocene) of the Tizi Ouzou Basin is mainly characterized by two distinctive sedimentary cycles: a basal cycle, purely detrital, represented by a thick series of conglomerates and sandstones, underlies a transgressive marine cycle represented by marls and sandstone slabs. The latter begins with thin sequences of sandy marls and sandstone slabs, and then gradually evolves into very thick sequences of crumbly and indurated blue marl capped by sandstone slabs. These different facies are marked by various indicators of depositional environmental conditions, such as hydrodynamic features, climatic patterns, and burrow traces, which allow for a precise determination of the succession of paleoenvironments that gave rise to these deposits. The various burrow traces provide a strong indication of how organisms interact with changing paleoenvironmental conditions. Burrow traces are crucial in paleoecology as they provide information about the life habits of fossil organisms and are valuable for paleoenvironmental studies (Savrda CE., Palaios 10:565–577, 1995). They are studied and subdivided into ichnofacies reflecting the conditions of the organism's living environment, in terms of hydrodynamics and distance from the coast. The vertical distribution of planktonic foraminiferal species allowed us to conduct a biostratigraphic study, providing precise ages of the formations. In addition, we deduced a pelagic index from the ratio of planktonic and benthic foraminifera. Indeed, the spatial distribution of benthic foraminifera is strongly influenced by bathymetric conditions, making them optimal indicators of paleoenvironments. Their frequency makes it possible to directly deduce the paleobathymetric conditions of depositional environments. To sum up, the transgressive cycle represented by marls in the Tizi Ouzou basin shows various lithofacies indicating changes in paleoenvironments. Ichnofacies provide more details on this change, while the pelagic index reflects paleobathymetry evolution. The age of the formations is determined through a biostratigraphic study. [ABSTRACT FROM AUTHOR]

Alpine ice core research has long focused on a few suitable drilling sites at high elevation in the Western European Alps, assuming that the counterparts at lower elevation in the eastern sector are unsuitable for paleoenvironmental studies, due to the presence of melting and temperate basal conditions. However, it has been demonstrated that even in the Eastern Alpine range, below 4,000 m a.s.l., cold ice frozen to bedrock can exist. In fact, millennial-old ice has been found at some locations, such as at the Weißseespitze (WSS) summit ice cap (Ӧtztal Alps, 3,499m a.s.l.), where about 6 kyrs appear locked into 10mof ice. In this work, we present a full profile of the stable water isotopes (δ18O, δ²H), major ions (Na+, K+, Mg2+, Ca2+, NH4+, Cl-, NO3-, SO42-), levoglucosan, and microcharcoal for two parallel ice cores drilled at the Weißseespitze cap. We find that, despite the ongoing ice loss, the chemical and isotopic signatures appear preserved, and may potentially offer an untapped climatic record. This is especially noteworthy considering that chemical signals of other archives at similar locations have been partially or full corrupted by meltwater (i.e., Silvretta glacier, Grand Combin glacier, Ortles glacier). In addition, the impurity concentration near the surface shows no signs of anthropogenic contamination at WSS, which constrains the age at the surface to fall within the pre-industrial age. [ABSTRACT FROM AUTHOR]

The analysis of phytoliths is a recent addition to the geosciences and has found applications in various fields over the last few decades, including palaeoenvironmental studies in fluvial environments. As a developing field, it is essential to carry out studies aimed at creating a modern reference collection that fills an information gap on the production of phytoliths by plants in this environment. These studies are essential to increase the reliability and accuracy of phytolith research in reconstructing past vegetation patterns and compositions. This study is the first with the aim of creating a pioneer collection of phytoliths in fluvial environments of the Upper Paraná River, addressing woody eudicotyledon species of greater representation on the Três Ilhas (Three Islands) Archipelago. The phytoliths were extracted from the leaves of 51 species from the botanical collection of the Nupélia herbarium (HNUP) using the dry ashing extraction method. The analysis found that 21 plant families established on the site have some kind of silica accumulation and 34 species are producers of phytoliths with an identifiable shape and size (<5um). It was confirmed the Moraceae family produces Acute bulbosus (with ramifications), both considered diagnostic at family level. Confirming the current literature on the subject, redundancy of the spheroid ornate and spheroid psilate morphotypes was observed in woody plants. Although no new morphotypes were found, the information will contribute to studies on the evolution of fluvial geoforms. [ABSTRACT FROM AUTHOR]

Charcoal is commonly preserved in both natural and artificial sediments, and is intensively used in paleontological, paleoenvironmental, and archaeological studies due to the abundant bio-information it contains. The biochemical properties of charcoal are also used for paleoclimatic reconstruction; however, the reliability of this approach has been challenged due to a lack of clarity on how physicochemical properties change during the charring process, as well as the temperatures required for charcoalification. To address this lack, in this study, Qinghai spruce and Chinese pine wood samples from the northeastern Tibetan Plateau were heated at different temperatures and for different lengths of time under restricted oxygen conditions. The reflectance; carbon, nitrogen, and oxygen content; and tracheid morphology were quantified before and after heating to assess changes related to the charring process. Archaeological charcoal remains were then evaluated to determine the charcoalification temperatures by comparing with the experimental results. The minimum temperature required for wood charcoalification was ~300 ℃, while temperatures recorded by archaeological charcoal were concentrated at 400-500 ℃. During the charring experiments, the tracheid cell walls gradually homogenized, and tracheid cell wall thickness and lumen area decreased by ~20%. On average, 50% mass losses were observed; the carbon and oxygen content (% wt.) approximately changed from 47% to 60% and 48% to 35% respectively, while the nitrogen content (% wt.) fluctuated around 0.2%. The reflectance increased slightly from 0% to 0.5%. We propose that the charcoalification of wood tissue refers to charring (in restricted air) and carbonization (in the almost absence of air) when the wood is exposed to a heat source, which then finally transforms into a black, inert solid. This quantitative study provided valuable data and a thorough assessment of the process of wood charcoalification, as well as accurately estimated the feasibility of using charcoal physicochemical properties in paleoclimatic research. [ABSTRACT FROM AUTHOR]

The shores of the Adriatic Sea since Prehistory have been a crossroads of cultural, human and commercial exchanges between West and East and in all this the Roman civilization could not have failed to exploit this internal "canal" that united the shores of the Italian and Balkan peninsula. The Adriatic Sea is also unique from an environmental and climatic point of view, with marine and wind currents coming from Africa and the Balkans meeting and colliding, resulting in rather intense meteorological cycles. All this was decisive in the history of the Adriatic and its coasts, during the Roman period; how much natural environmental conditions have influenced anthropic ones and vice versa; through a review of paleoenvironmental and archaeobotanical studies we will try to define the impact that Romanization had on the territories and environments along the two western and eastern shores of the Adriatic. [ABSTRACT FROM AUTHOR]

Europium (Eu) in coal and sedimentary rocks has important mineral resource potential as well as being a crucial parameter in geochemical studies that can represent changes in the depositional environment during coal deposition and identify the depositional source region. Therefore, it is essential to realize the precise measurement of Eu in coal as this could be a useful parameter for paleoenvironmental reconstruction studies and the exploration of mineral resources. During inductively coupled plasma mass spectrometry (ICP-MS) analysis, polyatomic ions of Ba may interfere with Eu, causing the observed value to be higher than the actual value. This paper develops a new approach for Eu determination by using a high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The mass spectral interference and correction of Eu in the coal and sedimentary rock samples at low, medium, and high resolutions were investigated. The results showed that in the high-resolution mode (resolution = 10,000 amu), the interference of polyatomic ions of Ba could be distinguished from Eu; hence, Eu was determined under this circumstance. Under the optimal experimental circumstances, the detection limit was 0.006 μg/mL, the relative standard deviation was 0.80%–1.22%, and the linear correlation coefficient of the standard curve was over 0.9999. The recoveries of the 103Rh internal standard solution ranged from 94.41% to 100.10%. This method was verified using standard reference materials and selected samples, which demonstrated its high sensitivity, accuracy, and reliability, and a low detection limit, making it appropriate for detecting Eu in samples of coal and sedimentary rocks. [ABSTRACT FROM AUTHOR]

This study investigates the paleoenvironmental conditions, paleo-biogeographic affinities, and paleoecological significance of Paleocene ostracods from the Ewekoro Formation in the eastern Dahomey Basin, Nigeria. Less attention has been given to ostracods study in Nigeria. The research aimed at understanding the paleoecological and paleobiogeographic distributions of the ostracods from borehole data in the eastern Dahomey Basin of Nigeria and their relationship to other African basins. The carbonates samples were analysed using sedimentological and micropaleontological methods. Eleven carbonates samples that were carefully collected from borehole BH-22 and processed based on Nagy et al. (1988) procedure were used for this study, yielding 18 well-preserved ostracod species. These species include Soundanella laciniosa triangulata, Bardia ilaroensis, Nigeroloxoconcha acgyptiaca, Paracosta kefensis, Xestoleberis tunisiensis, and others. The identified assemblages reflect a heterogenous neritic zone, ranging from high-energy nearshore to low-energy outer neritic settings. Species such as Bardia ilaroensis and Nigeroloxoconcha aegyptiaca, indicate shallow marine or estuarine environments, while Cytherella species suggest deeper, low-energy conditions. The paleobiogeographic distribution supports a Trans-Saharan Seaway connection during the Paleocene-Eocene, linking the Southern Tethys and West African provinces. Ostracod species between the eastern Dahomey Basin and regions in North Africa, the Middle East, and other parts of West Africa indicate significant faunal interchange. For hydrocarbon exploration in the basin, the limestone units and interbedded light grey sandstone of the Ewekoro Formation suggest potential reservoirs, while black shales indicate potential source rock. The identified ostracods provide biostratigraphic markers enhancing the predictability of reservoir and source rock distribution in the basin. [ABSTRACT FROM AUTHOR]

Radiolarians have proven to be exceptional tools in biostratigraphic and paleoenvironmental studies despite their relatively low preservation potential in the sedimentary record. Reports of Upper Cretaceous radiolarians in high northern latitudes are scant, and their taxonomy is not often discussed in the few reports available in the literature. In this study, we describe one new genus and three new species of polycystine radiolarians from Upper Cretaceous strata of the northern mainland coast of Arctic Canada. The specimens were recovered from the Santonian–middle Campanian Smoking Hills Formation and the middle Campanian–Maastrichtian Mason River Formation and are assigned to the genus Canadasphaera n. gen. (Order Spumellaria) and the species Canadasphaera inuita n. sp., Kuppelella rusti n. sp., and Lithocampe? rara n. sp. The taxonomic notes provided in this study improve our understanding of Late Cretaceous radiolarians from high northern latitudes and serve as a foundation for future Cretaceous radiolarian research in Arctic regions. Canadasphaera: urn:lsid:zoobank.org:act:C6B7B702-4B74-472D-8893-0A41B93A5066, date of registration: 19 April 2024 Canadasphaera inuita: urn:lsid:zoobank.org:act:C30E555B-EE94-4680-87D1-5CE83E128461, date of registration: 19 April 2024 Kuppelella rusti: urn:lsid:zoobank.org:act:68ECB628-2E74-4748-ACA4-DD1A33B05837, date of registration: 19 April 2024 Lithocampe? rara: urn:lsid:zoobank.org:act:25E569B2-93A8-425F-BB7C-D29A0437763F, date of registration: 19 April 2024 [ABSTRACT FROM AUTHOR]

Subfossil remains of aquatic invertebrates found in lacustrine sediments are useful paleoenvironmental indicators. Strongly scleroticized chitinous body parts from the exoskeleton or exuviae from invertebrates are often the most resistant to degradation during syn- and post-depositional processes. Invertebrate mandibles and body parts that superficially resemble mandibles, such as claw-like appendages and pygopodia, are frequently found in sieved Quaternary lacustrine, palustrine, and deltaic sediments. Guides, catalogs and atlases have been published that are well suited for the identification of subfossil remains for several invertebrate groups, such as chironomids, cladocerans, and ostracods, among others. However, aquatic invertebrate remains of several ecologically important invertebrate groups continue to be underused in paleoenvironmental studies, in part, because there are few visual keys or other documentation sources (e.g. descriptions, catalogs or atlases) that increase awareness and facilitate identification. Here we present sets of digital photomicrographs of pre-identified aquatic invertebrate specimens collected from streams, lakes and ponds that have been chemically cleared to preserve structures that are observed in subfossil remains in sieved sediment samples, commonly the > 100 μm size fractions. In addition, we present examples of these structures from Quaternary lake-sediment samples and cite the dispersed literature that demonstrate that these remains are preserved and remain identifiable in the fossil record. We document mandibles from several taxonomic groups that include Crustacea: Amphipoda, Isopoda, Ostracoda, and Notostraca; and Insecta orders: Coleoptera, Diptera, Ephemeroptera, Hemiptera, Odonata, Lepidoptera, Megaloptera, Plecoptera, and Trichoptera. The compilation of microphotographs also includes pygopodia and claw appendages of Plecoptera and Trichoptera, with additional images of other common invertebrate mouthpart and head remains. We describe several types of fossilizing structures that are, to our knowledge, not previously described in the paleoecological literature (e.g. mandibles of amphipods or plecopterans) but also show that some structures are considerably more variable than expected based on available descriptions, such as the mandibles of Ephemeroptera or Trichoptera, and that these can potentially be separated into different morphotypes useful for identification of subfossil material. We also discuss the potential of analyzing and interpreting the additional remains together with the remains of more commonly analyzed invertebrate groups (e.g. Chironomidae) to contribute to paleoenvironmental interpretations, which will allow assessments of functional groups (e.g. predators, shredders, grazers) or habitat types (e.g. littoral, profundal or lotic environments) that aquatic invertebrate remains originate from. [ABSTRACT FROM AUTHOR]

Copyright of Archaeology & Science / Arheologija i Prirodne Nauke is the property of Institute of Archaeology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Alpine ice core research has long focused on a few suitable drilling sites at high elevation in the Western European Alps, assuming that the counterparts at lower elevation in the eastern sector are unsuitable for paleoenvironmental studies, due to the presence of melting and temperate basal conditions. However, it has been demonstrated that even in the Eastern Alpine range, below 4,000 m a.s.l., cold ice frozen to bedrock can exist. In fact, millennial-old ice has been found at some locations, such as at the Weißseespitze (WSS) summit ice cap (Ötztal Alps, 3,499 m a.s.l.), where about 6 kyrs appear locked into 10 m of ice. In this work, we present a full profile of the stable water isotopes (S18O, S2H), major ions (Na+, K+, Mg2+, Ca2+, NH4+, Cl-, NO3-, SO42-), levoglucosan, and microcharcoal for two parallel ice cores drilled at the Weißseespitze cap. We find that, despite the ongoing ice loss, the chemical and isotopic signatures appear preserved, and may potentially offer an untapped climatic record. This is especially noteworthy considering that chemical signals of other archives at similar locations have been partially or full corrupted by meltwater (i.e., Silvretta glacier, Grand Combin glacier, Ortles glacier). In addition, the impurity concentration near the surface shows no signs of anthropogenic contamination at WSS, which constrains the age at the surface to fall within the pre-industrial age. [ABSTRACT FROM AUTHOR]

The Lagoa Salgada is located in the Paraíba do Sul river delta plain on the coast of Rio de Janeiro state, Brazil, and is one of the few lagoons in the world that have well-developed recent stromatolites. Lagoa Salgada is a hypersaline lagoon formed in a very complex environmental system subjected to terrestrial and oceanic influences under different sea level regimes and climate variations. In addition, sediment and stromatolites are characterized by unusually positive inorganic δ13C VPDB values. For this reason, it has been the target of several geological and paleoenvironmental studies, which, in their great majority, require a geochronological technique in order to determine the changes in the environment over time. When radiocarbon (14C) dating is used, it is necessary to consider some details as the source of 14C in the environment and perform 14C ages calibration accordingly. In the present paper, a bibliographic survey was carried out in order to review the data treatment and improve the environmental evolution discussion based on accurate calibration. Using the Marine20 curve and an undetermined ΔR, we generated growth and depositional models to establish an overview of the formation of this lagoon. [ABSTRACT FROM AUTHOR]

A multidisciplinary study, including geomorphological, stratigraphic, paleontological and archaeological methods and techniques, allowed for a detailed exploration of coastal landforms and environments in front of the ancient city of Pompeii (southern Italy). The famous site of Pompeii sits on a small volcanic hill in the alluvial-coastal plain of the Sarno River, very close to the ancient paleoshoreline. When the Roman city was buried during the eruption of Vesuvius in 79 CE, pyroclastic fall and flow deposits covered the urban centres and ancient coastal landforms. In this study, 83 new boreholes were carried out up to a depth of 10 m. Some of them (15) were analysed for their sedimentological, stratigraphical and paleontological characterisation, in order to reconstruct the sedimentary environments in 79 CE. The data collected allow for new hypotheses to be formulated regarding the paleoshorelines, as well as the 79 CE coastal landforms and environments. In particular, litho-stratigraphic and fossil assemblages highlight the presence of shallow marine environments in a large back-ridge depression, named Masseria Curati, that is located just outside the city walls. This hypothesis opens new insights on the unknown location of the harbour of the Roman city.

The Northern Mesoamerican Frontier was a complex multicultural region characterized by frequent human settlement changes and shifts in agricultural conditions during the Late Preclassic period (~400 BCE-150 CE). Here, we report a high-resolution paleoenvironmental record from the varved sedimentary sequence of the crater maar La Alberca which spans the Late Preclassic (~400 BCE-150 CE) to part of the Early Classic period (~150 CE-250 CE) corresponding to Late Chupicuaro phase (400 BCE-100 CE) and Mixtlan phase (0–250 CE). Our work aims to study the paleoenvironmental conditions during the rise of agriculture in the Northern Mesoamerican Frontier and provide insights related to landscape alteration by human activity. To reach these aims, a multiproxy investigation was conducted by means of varve counting, high-resolution XRF scans, magnetic susceptibility, pollen data and fecal stanol biomarkers as a proxy for human population change. Our results reveal two varve type. Type 1 is characterized by the alternation of detrital-organic layers and aragonite layers, type 2 by alternating detrital-organic layers with an organic layer formed by diatom frustules and aragonite layers. This study suggest that the increase of erosion by human activity during the Late Chupicuaro phase (400 BCE-100 CE) and the start of the Mixtlan phase (0–250 CE) coincide with a high percentage of Amaranthaceae pollen, a rise of sedimentation rates, increase in nutrient content and the increase of human waste flux interpreted with the (Coprostanol + epi) :((Coprostanol + epi)+cholestanol biomarker. Moreover, a wetter period (~137 BCE-37 CE) interpreted during the Late Chupiacuaro phase and the start of the Mixtlan phase could suggest favorable environmental conditions for the establishment of agriculture. [ABSTRACT FROM AUTHOR]

This study investigates paleoenvironmental changes at the Paleolagoa Seca site, an Upper Quaternary locality of lacustrine origin in central Brazil. We present charcoal and pollen analyses of this sedimentary sequence, and assess how they compare with previously published fossil macroflora and paleoclimatic reconstructions of the same site and adjacent localities. We identified a mosaic of savannas, forests and flooded environments before 43 ka bp with the presence of evergreen forest formations. For this period, we found charcoal particles resulting from natural fires that represent the oldest Quaternary record of fire in the Cerrado. By conducting a morphological analysis of charcoal particles, we were able to identify that the primary constituents of fire fuel were grasses, which suggests that surface fires were prevalent. During this Pleistocene wet phase, fire probably played a vital role in preserving areas of open vegetation. In contrast, at ~43 ka bp, an open landscape and a drier‐than‐present climate characterized the Paleolagoa Seca site. [ABSTRACT FROM AUTHOR]

We present a series of 1-km spatial resolution rebound (isobase) surfaces based on publicly distributed predictions obtained from the glacio-isostatic adjustment models known as ICE-5G (VM2 L90), ICE-6G_C (VM5a) and ICE-7G_NA (VM7). Our objective is to provide readily accessible tools for a broad range of geological and paleoenvironmental studies, and to facilitate direct comparison between models' predictions and field-based observations. Rebound surfaces were interpolated at the scale of North American ice sheets (35.5°-89.5°N; 45°-165°W) and for each time increment of the models (1,000-500 yrs, between 26,000-21,000 yrs BP and present-day). The assessment of the interpolations indicates that the rebound surfaces have an overall vertical accuracy of ∼0.4 m compared to original ICE-xG outputs. These rebound surfaces were combined with the GEBCO 2021 present-day elevation grid to reconstruct the paleotopography for each time increment of the models and are all presented as raster files that can be easily integrated into geographical information systems. The resulting datasets therefore provide a unique support for geological, paleoenvironmental and archeological studies. [ABSTRACT FROM AUTHOR]

Sedimentary records from the Kumtag (also known as Kumtagh) Desert (KMD) in northwestern China are investigated to better understand Late Quaternary paleoenvironmental changes in this hyper-arid region. Presented here are the results of probably the first systematic survey of sedimentary sequences from the KMD, with the chronology determined by the optically stimulated luminescence dating. The variation of sedimentary facies, supported by granular and geochemical paleoenvironmental proxies, is used to decipher the history of Late Quaternary environment changes. The results demonstrate that a constantly dry condition characterized the eastern KMD since the last glacial maximum, but with occurrences of wetter periods. From ca. 17 to 15 ka, fluvial activity was probably triggered by melting of glaciers in mountains located south of the KMD. A distinctly drier stage (ca. 13–7 ka) was recognized due to the prominent occurrence of aeolian sands. A wetter environment likely persisted between ca. 4.4 and 2.2 ka, consistent with evidence of human activities. While the causes of paleoenvironmental changes in the eastern KMD are still a matter of debate, the melting of glaciers in the Altyn-Tagh Mountains in the south must be considered as an important factor. [ABSTRACT FROM AUTHOR]

One of the most abundant species of bivalves found on modern beaches and Quaternary deposits in the San Matías Gulf (Argentinian Patagonia, SW Atlantic Ocean) is Glycymeris longior. Its high abundance and broad geographical distribution turn G. longior into a target species for taphonomical studies. Here, we described the taphonomic signature registered on its shells from San Antonio Bay (San Matías Gulf, Río Negro). This study will contribute to future taphonomic comparisons in the SW Atlantic Ocean, as well as in other Quaternary deposits, and provide insight into the spatial variation of the taphonomic processes influenced by the environment. Glycymeris longior valves from the Holocene Punta Delgado deposits showed two taphonomic signatures whose shell assemblages were differentiated by fragmentation, rounding and cementation intensities. Shells from PD2018A and PD2018B (two sampling localities representing similar environments) were subject to continuous and low-energy water flow. Those remained in a low-intensity hydrodynamic sediment-water interface that would favor high shell cementation. On the other hand, shells from PD2016 were also subject to continuous but more energetic water flow. Those would remain in the taphonomic active zone for enough time to confer smooth edges and to be colonized by clionid sponges but not favorable enough for carbonate precipitation. The Punta Delgado site was interpreted as a protected area during the Holocene (last 4200 yrs.), similar to the modern one, but with differences in carbonate precipitation as the product of differences in water flow intensities. Finally, the high mechanical resistance of G. longior shells, together with its abundance and broad geographical distribution, turn this species into a suitable target taxon for further taphonomic and ecologic analyses and comparisons. [ABSTRACT FROM AUTHOR]

An international, multidisciplinary research group is proposing the "NICA-BRIDGE" drilling project, within the framework of the International Continental Scientific Drilling Program (ICDP). The project goal is to conduct scientific drilling in Lake Nicaragua and Lake Managua (Nicaragua, Central America) to obtain long lacustrine sediment records to (a) extend the neotropical paleoclimate record back to the Pliocene, making it one of the longest continental tropical climate archives in the world, and to (b) provide geological data on the long-term complex interplay among tectonics, volcanism, sea-level dynamics, climate change, and biosphere. The lakes are the two largest in Central America, and they are located in a trench-parallel half graben that hosts the volcanic front, which developed during or prior to the Pliocene, as a consequence of subduction-related tectonic activity. The lakes are uniquely suited for multidisciplinary scientific investigation as their long, continuous sediment records (several Myr) will facilitate the study of (1) terrestrial and marine basin development at the southern Central American margin, (2) alternating lacustrine and marine environments in response to tectonic and climatic changes, (3) the longest record of tropical climate proxies, (4) the evolution of (and transition between) the Miocene to Pliocene/Pleistocene and Pleistocene to present volcanic arcs, which were separated by slab rollback, (5) the significance of the lakes as hot spots for endemism, and (6) the Great American Biotic Interchange at this strategic location, i.e., the N–S and reverse migration of fauna after the land bridge between the Americas was established. The planned ICDP project offers an opportunity to explore these topics through continent-based seismological, volcanological, paleoclimatological, paleoecological, and paleoenvironmental studies, combined with an International Ocean Discovery Program (IODP) drill project to explore its oceanic continuation. In preparation of this drilling project, an ICDP workshop was held in Montelimar, Nicaragua, on 2–5 March 2020 to develop drilling strategies and refine scientific questions, objectives, and hypotheses. The workshop was organized and hosted by the principal investigators and the Instituto Nicaragüense de Estudios Territoriales (INETER), with funding from the ICDP. Forty-five researchers from 12 countries participated in the workshop, including representatives from ICDP. During the workshop, previous research data on the study lakes, including new recent surveys, were reviewed, and a three-phase strategy for the proposed research was developed. The aim of Phase 0 is to complement the pre-site surveys where we identified the need for further data. In Phase I, with ICDP support, we will obtain sediment cores ∼ 100 m long, which will allow us to investigate many of the scientific questions. Based on the data from those drill cores, coring locations will be identified for a future Phase II, which we envisage as a combined ICDP/IODP project to collect deep drill cores in the lakes and the offshore Sandino Basin in order to extend Phase I results to much deeper time. The Sandino Basin is the oceanic continuation of the depression in which the studied lakes are located, and complementary marine drilling will improve the understanding of the evolution of this complex margin. [ABSTRACT FROM AUTHOR]

• Variable pollen-phytolith preservation, production, dispersal affect interpretation. • Modern pollen-phytolith assemblages reflect the varying vegetation composition. • Pollen and phytolith proxies do not track same primary vegetation signals. • Pinus was overrepresented in the samples across the plots except in the forests. • Modern pollen-phytolith assemblages can improve palaeoenvironmental interpretations. In palaeoenvironmental reconstructions, few studies have focused on comparing the presence of pollen and phytoliths in surface sediments to the local vegetation. Notwithstanding inherent differential pollen and phytolith preservation, production, and dispersal, which affect their recovery and interpretation in sediment archives, there remains a need to explore modern pollen-vegetation, phytolith-vegetation and pollen-phytolith relationships to improve palaeoenvironmental reconstructions. We carried out palynological and phytolith analysis on six surface sediment samples linked to the botanical survey of five vegetation survey plots at Gustav Klingbiel Nature Reserve, Mpumalanga province in northeastern South Africa, to understand the relationships between the modern pollen and phytolith assemblages in the surface sediments and the contemporary vegetation of the study area. Correspondence Analysis (CA) was undertaken to examine the fingerprint of the local vegetation in the modern pollen-phytolith assemblage and evaluate whether the phytolith and pollen assemblages were tracking each other. CA illustrated that pollen and phytolith proxies are not tracking the same primary vegetation signals; modern pollen assemblages best represent the components of forest and wetland vegetation. In contrast, modern phytolith assemblages best represent grassland vegetation. Our study shows that differential pollen and phytolith preservation, production and dispersal significantly affect sediment records more than anticipated, thus combining multi-proxies (e.g., phytoliths, pollen) provides a more accurate basis for the interpretation of fossil spectra in palaeoenvironmental reconstructions. [ABSTRACT FROM AUTHOR]