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The stratigraphic principle of superposition assumes that sediments at surface are youngest. And yet, patches of older preserved landscapes continue to be identified in the regions formerly covered by the Laurentide Ice Sheet. Two gravel pits, at the edge of the western Hudson Bay Lowland near the geographic centre of the North American Ice Sheet Complex, reveal additional patches where older glacial and nonglacial sediment is preserved. These sites expose 1–4 m of a darker, highly overconsolidated, clayier till, and 0–2 m of a lighter, less consolidated, sandier till over glaciofluvial and post-glacial gravels and sands; the waning stages of deposition occurred at 214 ± 22 ka (1σ minimum age model quartz grain optical age estimates, n = 2). This was during the latter end of the cool Marine Isotope Stage (MIS) 7-d (within 1σ range) or near the end of MIS-8 (within 2σ range). Next followed a warmer period similar to, or warmer than, present day with higher precipitation; inferred from pollen and macrofossils deposited in nonglacial low-energy floodplain or pond sediments. Our study highlights the need to accurately date Quaternary sediments, given that the shallowest nonglacial sediments at both gravel pits were deposited during an old (MIS 7) interglacial; there is likely no record of the youngest interglacial (MIS 5). Preservation of older sediment also means that in Quaternary stratigraphy, disjoint regional nonglacial "organic marker beds" should not automatically be considered correlative. Identification of similar "old" patches, together with till stratigraphy and composition, is essential to accurately model glacial sediment transport over time. [ABSTRACT FROM AUTHOR]

The persistence and size of the Greenland Ice Sheet (GrIS) through the Pleistocene is uncertain. This is important because reconstructing changes in the GrIS determines its contribution to sea level rise during prior warm climate periods and informs future projections. To understand better the history of Greenland's ice, we analyzed glacial till collected in 1993 from below 3 km of ice at Summit, Greenland. The till contains plant fragments, wood, insect parts, fungi, and cosmogenic nuclides showing that the bed of the GrIS at Summit is a long-lived, stable land surface preserving a record of deposition, exposure, and interglacial ecosystems. Knowing that central Greenland was tundra-covered during the Pleistocene informs the understanding of Arctic biosphere response to deglaciation. [ABSTRACT FROM AUTHOR]

This study presents the results of a detailed paleoclimate investigation on stalagmite YL-1 (Yelini Cave, Türkiye). YL-1 grew between 117.13 (+0.57/−0.44) ka and 114.87 (+1.63/−2.89) ka within Greenland Stadial 26, indicating a positive moisture balance during the stadial conditions in this semi-arid region. Rainfall is significantly affected by sub-cloud and surface evaporation and decreasing net effective winter precipitation is recorded by high isotope values. Enriched δ18O and δ13C at 116.65 (+0.51/−0.39) ka are interpreted as a drought event that took place ca. 400 years before the end of the MIS 5e. This event, which was reported simultaneously in marine and terrestrial archives in the Northern Hemisphere, is a result of decreased cyclone activity linked to weakening of the Atlantic meridional overturning circulation. 87Sr/86Sr values of YL-1 are close to the host-rock values. Decreased 87Sr/86Sr ratio at 116.67 (+0.54/−0.38) ka reflects the intensified water–rock interaction due to lower precipitation. Along with prior calcite precipitation effect, this is also observed by increased Mg/Ca and Sr/Ca, while low P, Cu, Be, Y, and Zr concentrations indicate a lowered amount of soil-derived colloidal material. The MIS 5e/5d transition is marked by reduced insolation and enriched δ18O at 116.24 (+0.53/−0.86) ka. The Greenland Interstadial 25 phase at 115.87 (+0.83/−1.71) ka is represented by more negative δ18O and δ13C. [ABSTRACT FROM AUTHOR]

We investigated benthic foraminifera in cores GPC03 and GPC04 in the northeast tropical Indian Ocean (TIO) over the past ∼450 ka to evaluate the ballasting effect of particulate organic matter (POM) and the long‐term zonal change during the mid‐Brunhes dissolution interval (MBDI). Today, interannual climate and oceanographic variability in the TIO is governed by the Indian Ocean Dipole (IOD), which manifests as asymmetric zonal oceanographic change. Previous studies have been conducted to uncover such zonal paleoceanographic change and have referred to their climatic pattern as an "IOD‐like mode." In the northeast TIO, after ∼390 ka, contributions of lithogenic matter and %Nuttallides umbonifer were unusually high under the better carbonate preservation conditions during glacial periods. Our findings suggest that the effect of lithogenic matter from the Ganga‐Brahmaputra‐Meghna River system increased significantly under glacial low sea‐level conditions, possibly by lateral transport along the continental slope. As a result, ballasting of POM seemed more efficient during glacial periods by abundant riverine lithogenic particles. In addition, the long‐term (∼320–200 ka) trend of high benthic foraminiferal accumulation rate (BFAR) and several short‐term fluctuations of high BFAR at ∼310, ∼280, ∼260, and ∼240 ka were discernible. We attribute these changes to increased paleoproductivity driven by upwelling, which may be related to the Indian Ocean equatorial westerlies and Indian summer monsoon dynamics via variations arising from precession. We propose that a long‐term mean‐state transition of IOD‐like mode might have occurred during the MBDI, similar to other hypotheses invoking concomitant changes in the El Niño‐Southern Oscillation system. Key Points: Nuttallides umbonifer were commonly observed in the glacial sediments at the Ninetyeast Ridge of the northeast tropical Indian OceanBallasting of particulate organic matter by the riverine lithogenic particles was more efficient during the glacial periods at the Ninetyeast RidgeWe found evidence for a long‐term mean‐state transition in northeast tropical Indian oceanography since the mid‐Brunhes period [ABSTRACT FROM AUTHOR]

Climatic oscillations during the Pleistocene played a major role in shaping the spatial distribution and demographic dynamics of Earth's biota, including our own species. The Last Interglacial (LIG) or Eemian Period (ca. 130 to 115 thousand years B.P.) was particularly influential because this period of peak warmth led to the retreat of all ice sheets with concomitant changes in global sea level. The impact of these strong environmental changes on the spatial distribution of marine and terrestrial ecosystems was severe as revealed by fossil data and paleogeographic modeling. Here, we report the occurrence of an extant, inland mangrove ecosystem and demonstrate that it is a relict of the LIG. This ecosystem is currently confined to the banks of the freshwater San Pedro Mártir River in the interior of the Mexico-Guatemala El Petén rainforests, 170 km away from the nearest ocean coast but showing the plant composition and physiognomy typical of a coastal lagoon ecosystem. Integrating genomic, geologic, and floristic data with sea level modeling, we present evidence that this inland ecosystem reached its current location during the LIG and has persisted there in isolation ever since the oceans receded during the Wisconsin glaciation. Our study provides a snapshot of the Pleistocene peak warmth and reveals biotic evidence that sea levels substantially influenced landscapes and species ranges in the tropics during this period.

Mean Sortable Silt (SS) size records in the hemipelagic deposits at Site U1452 (IODP 354) in the lower Bengal Fan are presented here to reconstruct the bottom water circulation strengths in the Bay of Bengal (BoB) during the last 200 ka (Marine Isotopic Stage 1 to 6). To eliminate possible amplitude shifts in SS size due to terrestrial sediment flux or turbiditic interventions, sedimentation history at the site is decomposed using End Member Analysis (EMA). SS size record in the BoB is mostly unimpacted by the terrestrial sediment flux and turbidity current deposition; hence the size sorting signature in SS records is best described to have arisen from benthic boundary layer current intensity. SS size record in the BoB indicates reduced bottom water flow speed during glacials (MIS 2 and 6), concomitant with the greater import of Antarctic/ Southern Ocean (SO) derived deep waters and increased speed during interglacials (MIS 1, 3 and 5) corresponding to an increased proportion of Northern Atlantic derived deep water mass in the northern Indian Ocean. Glacial and stadial decline in flow speed reflects on the density reversal between two deep water mass end members in the SO and a shoaled Atlantic meridional overturning circulation (AMOC). On the other hand, faster flow speed during the climate optima at MIS 5.5 and other warm substages of MIS 5 as well as during the Holocene present a deep and strong AMOC. Reduced bottom water circulation strength in the BoB during the MIS 5.5 to 5.4 transition might have contributed to atmospheric CO2 drawdown and global cooling during the early stages of glacial inception along with deep circulation changes in the SO. Also, millennial-scale variability in circulation strength in the BoB is linked to oceanic frontal shift in high northern latitudes and deepwater formation manifesting in reduced flow strength associated with local cold anomalies (C28-C23), successively culminating into glacial inception at MIS 5.4. Reduced flow speed is also observed during some of the Heinrich events indicating a strong teleconnection between deep North Atlantic and BoB. Productivity changes in the BoB might as well have been influenced by variable fluxes of northern and southern sourced water mass during the last 200 ka. [ABSTRACT FROM AUTHOR]

The Deckenschotter is a fluvial to glaciofluvial gravel unit in northern Switzerland and southern Germany. The deposits are considered the oldest preserved glacial to interglacial Quaternary deposits in the northern Alpine foreland and are thus important geomorphological markers for landscape evolution. Nevertheless, the age of the deposits is only approximately known and subject to controversial debates. This study presents the results of an extensive palaeomagnetic investigation carried out on intercalated fine-grained sediments at 11 sites of the Höhere Deckenschotter (HDS) and at 5 sites of the Tiefere Deckenschotter (TDS). The HDS show reversed and normal magnetisations, indicating deposition > 0.773 Ma, while the TDS exhibit only normal directions. Age constraints for the different sites are discussed in the light of evidence from other studies. The study therefore clearly supports the efforts to determine the age of the Deckenschotter. As data from previous palaeomagnetic studies on the HDS and TDS have not been published or preserved, this is in fact the only data-based palaeomagnetic study available. [ABSTRACT FROM AUTHOR]

The Optically Stimulated Luminescence (OSL) age database of Finland was established, and it includes all of the published OSL age results from different sediment sequences in Finland. The OSL database includes ~180 published OSL ages ranging from 235,000 years to 300 years; that is, from the Middle Saalian interstadial to the present. Two statistical clustering methods, K-means and model-based clustering with the package mclust, were used to analyze the internal structure of the assembled OSL data. The results of these analyses were also compared to the established Northwest European (Fennoscandian) chronostratigraphical stages. When the data were analyzed by the K-means method, the “right” number of clusters (K) was seven. The model-based clustering method (K = five) created bigger clusters for the youngest and the oldest ages compared to the K-means clusters. Both methods show that the ages followed the increasing trend from the youngest to the oldest, and the standard error of ages was constantly increasing except in the age group 70–115 ka, where the standard errors were exceptionally high. Seven clusters obtained from the age data corresponded relatively well with the number of stratigraphically established interglacials and interstadials in the late Middle and Late Pleistocene in Fennoscandia. The exceptionally large standard error of ages in the Early Weichselian age group 70–115 ka might result from mixing of heterogeneous and poorly or partly bleached mineral material from both Eemian and Early Weichselian sediment layers. The OSL-dated Middle Saalian interstadial sediments in the data support a strong stadial and interstadial variation also before the Late Pleistocene.

Pollen and carbon isotope data from Natural Trap Cave provides insights into the environmental conditions of the Bighorn Basin, in north-central Wyoming, USA during the time intervals 151.1 to 132.2 cal ka BP, 51.8 to 17.4 cal ka BP, and 10.4 cal ka BP to present. Similarities between the buildup of the penultimate and last glacial maxima include abundant Artemisia, Amaranthaceae, Asteraceae, and Poaceae pollen, which, when combined with high δ13C values (>−25.0‰) and low plant discrimination values (18.0–19.0‰) from sedimentary organic matter, indicate steppe-like, cold-dry conditions. Between 151 and 142.5 cal ka BP, abundant Poaceae associated with much lower δ13C values (−28.0‰ to −26.0‰) and higher plant discrimination values (19.0‰–21.0‰) could be indicative of relatively wet summers. Similarly, after 25 cal ka BP increases in Poaceae may indicate wet conditions during the growing season. Holocene conditions differ from the earlier sections of the record, with greater arboreal pollen abundance (i.e., Pinus), consistent with woodland expansion in the region. Carbon isotope data from sedimentary organic matter show the Holocene was more humid than the glacial conditions of the late Pleistocene. This is especially clear at the start of the Holocene when a large negative carbon isotope excursion (CIE, < −28.0‰) occurred, providing a distinct chemostratigraphic marker defining the Pleistocene-Holocene boundary within these cave sediments. The association of this CIE with a pronounced spike in Pinus pollen supports an interpretation of a short-lived interval (<1000 years) of extremely warm, wet, forested conditions at this site. [ABSTRACT FROM AUTHOR]

Mesopelagic fishes are an important element of marine food webs, a huge, still mostly untapped food resource and great contributors to the biological carbon pump, whose future under climate change scenarios is unknown. The shrinking of commercial fishes within decades has been an alarming observation, but its causes remain contended. Here, we investigate the effect of warming climate on mesopelagic fish size in the eastern Mediterranean Sea during a glacial–interglacial–glacial transition of the Middle Pleistocene (marine isotope stages 20–18; 814–712 kyr B.P.), which included a 4°C increase in global seawater temperature. Our results based on fossil otoliths show that the median size of lanternfishes, one of the most abundant groups of mesopelagic fishes in fossil and modern assemblages, declined by approximately 35% with climate warming at the community level. However, individual mesopelagic species showed different and often opposing trends in size across the studied time interval, suggesting that climate warming in the interglacial resulted in an ecological shift toward increased relative abundance of smaller sized mesopelagic fishes due to geographical and/or bathymetric distribution range shifts, and the size-dependent effects of warming. [ABSTRACT FROM AUTHOR]

Despite more than a century of investigations, parts of the Quaternary stratigraphy of Denmark with their fragmented record of deposits remain ambiguous. Here we describe a newly found interglacial clay deposit from Ejby on Sjælland, Denmark, from a borehole at 55.695°N, 11.839°E (terrain elevation 5.7 m above sea level). We place the new occurrence on record and provide details of the macrofossil analysis of the sample. The clay contains remains of the present-day temperate bivalve Corbicula fluminalis and the caddis fly Hydropsyche contubernalis – both inhabiting rivers. The presence of C. fluminalis indicates that the deposit most probably is of Middle Pleistocene age, older than the last interglacial, the Eemian.

The study of trace fossils in glacially-influenced margins provides valuable insights into the changes in palaeoclimate and palaeoceanography during glacial-interglacial periods, by providing biological and ecological data of the benthic environment. Here we present a comprehensive ichnofabric characterisation of a sediment core located on an inter-canyon ridge on the SW Grand Banks Slope off Newfoundland, covering the Late Pleistocene–Holocene period (0–∼23 ka). The core analysis reveals 12 ichnogenera and an escape structure, with Phymatoderma , Tasselia , and Zoophycos being prominent and relatively abundant at specific levels. By examining the distribution of bioturbation content and degree along the core, we establish a strong association between moderate to high bioturbation and cold periods. The Last Glacial Maximum exhibits the highest abundance and diversity of trace fossils, particularly the deposit-feeding Phymatoderma and the deposit-feeding/equilibrium trace Tasselia , indicating benthic adaptation to seasonal food input and relatively high sedimentation rates. Conversely, the warmer deglaciation period shows limited bioturbation. Salinity stress may account for the abrupt decline in bioturbation degree during the early deglaciation. Additionally, the occurrence of large-sized Zoophycos coincides with the Younger Dryas cold event during the last deglaciation. These findings highlight the complexity of palaeoceanographic conditions and benthic environments in proximal glacially-influenced sites compared to distal hemipelagic and pelagic sites. The interplay between down-slope processes (such as turbidity currents and hyperpycnal flows) and along-slope processes (like contour currents) plays a crucial role in shaping the unique sedimentological regime of depositional sites and subsequently affecting the ichnofauna in glacially-influenced margins. • Bioturbation of glacially-influenced sediments was analysed in core. • Deposition during the Last Glacial Maximum is well-bioturbated. • Various down-slope and along-slope processes determine the ichnofauna. • Salinity stress accounts for decline in bioturbation during the early deglaciation. • Ichnofabrics reflect adaptation to seasonal food input and high sedimentation rate. [ABSTRACT FROM AUTHOR]

Plant fossils serve as critical proxies for interpreting past climates and environments, offering insights into the history of biosphere and climatic conditions. Here we describe a large tracheophyte cast, as well as the sedimentological settings in which it is preserved, expanding the paleobotanical database of the Itararé Group and contributing to the understanding of the LPIA in the Paraná Basin. This fossil occurs in Ponta Grossa, Paraná state, Brazil, within sedimentary levels interpreted as glacially dominated and deposited during the Late Paleozoic Ice Age (LPIA). The plant macrofossil is preserved as a cast, and the log is vertically oriented with a slight inclination in relation to the bedding plane. Taphonomic data indicate an allochthonous preservation, suggesting that the log was transported from inland areas to a plain before final burial. The identification of the tracheophyte cast within these glacial beds suggests that even in a dominantly glacial context, there were periods of episodic climatic amelioration. This finding implies that the climatic conditions during the Mississippian were not uniformly harsh, allowing the growth of vegetation as represented by the reported tracheophyta. • Record of a tracheophyte cast in allochthonous preservation in the basal Itararé Group. • The tracheophyte cast indicates episodic climatic amelioration, suggesting periods of frost-free conditions. • Dynamic climate changes and its impact on vegetation establishment in the Paraná Basin. [ABSTRACT FROM AUTHOR]

Abstract Marine isotope stage (MIS) 19 is considered to be the best orbital analog for the present interglacial. Consequently, clarifying the climatic features of this period can provide us with insights regarding a natural baseline for assessing future climate changes. A high-resolution radiolarian record from 800 to 750 ka (MIS 20 to MIS 18) was examined from the Chiba composite section (CbCS) of the Kokumoto Formation, including the Global Boundary Stratotype Section and Point for the lower–middle Pleistocene boundary on the Boso Peninsula on the Pacific side of central Japan. Millennial-scale oscillations in the Kuroshio warm and Oyashio cold currents were revealed by the Tr index, which is estimated using a simple equation based on radiolarian assemblages. The estimated Tr values ranged between 0.1 and 0.8 for MIS 18 through MIS 19, with minimum and maximum values corresponding to values observed off present day Aomori (41°N) and the Boso Peninsula (35°N), respectively. The observed patterns tended to be synchronous with the total radiolarian abundance associated with their production. Multiple maxima in radiolarian abundance occurred during periods of the Oyashio expanded mode before 785 ka and during periods of Kuroshio extension after 785 ka in MIS 19. Such increases in radiolarian abundance with the Kuroshio extension during MIS 19 are likely related to improvements in nutrient and photic environments with the development of a two-layer structure along the Kuroshio–Oyashio boundary zone. A similar pattern of millennial-scale climatic changes was also recognized in a precipitation record from the Sulmona Basin in central Italy, suggesting a close relationship with the CbCS record as a result of a large-scale climate system similar to the Arctic Oscillation in the northern hemisphere.

Along the south coast of the North Island of New Zealand, elevated Pleistocene marine terraces provide evidence for vertical deformation associated with active crustal faults and the westward subduction of the Pacific Plate at the southern Hikurangi margin. We have reassessed the age and elevation of these terraces. Optically Stimulated Luminescence (OSL) data of their cover bed sediments (20 new ages) provide the first numerical ages for most of these terraces. Shore platform elevations have been surveyed using differential Global Navigation Satellite System (GNSS) measurements of the wave-cut bedrock straths underlying these terraces. These new data allow the terraces to be temporally correlated across the margin. Seven different-aged terraces were identified and mapped along the Wellington south coast; these are preserved discontinuously between the westernmost site at Tongue Point, and Ngawi near Cape Palliser, to the east. The OSL data indicate that most of these terraces formed at MIS 5a, 5c, 5e (Last Interglacial) and 7a. The terraces are best preserved within the Hikurangi margin forearc, where they decrease in altitude towards the west, indicating long wavelength, westward tectonic tilting. The terraces are locally offset by a number of active crustal faults, most notably the Wairarapa and Ohariu faults. [ABSTRACT FROM AUTHOR]

Marine isotope stage (MIS) 19 is considered to be the best orbital analog for the present interglacial. Consequently, clarifying the climatic features of this period can provide us with insights regarding a natural baseline for assessing future climate changes. A high-resolution radiolarian record from 800 to 750 ka (MIS 20 to MIS 18) was examined from the Chiba composite section (CbCS) of the Kokumoto Formation, including the Global Boundary Stratotype Section and Point for the lower–middle Pleistocene boundary on the Boso Peninsula on the Pacific side of central Japan. Millennial-scale oscillations in the Kuroshio warm and Oyashio cold currents were revealed by the Tr index, which is estimated using a simple equation based on radiolarian assemblages. The estimated Tr values ranged between 0.1 and 0.8 for MIS 18 through MIS 19, with minimum and maximum values corresponding to values observed off present day Aomori (41°N) and the Boso Peninsula (35°N), respectively. The observed patterns tended to be synchronous with the total radiolarian abundance associated with their production. Multiple maxima in radiolarian abundance occurred during periods of the Oyashio expanded mode before 785 ka and during periods of Kuroshio extension after 785 ka in MIS 19. Such increases in radiolarian abundance with the Kuroshio extension during MIS 19 are likely related to improvements in nutrient and photic environments with the development of a two-layer structure along the Kuroshio–Oyashio boundary zone. A similar pattern of millennial-scale climatic changes was also recognized in a precipitation record from the Sulmona Basin in central Italy, suggesting a close relationship with the CbCS record as a result of a large-scale climate system similar to the Arctic Oscillation in the northern hemisphere. [ABSTRACT FROM AUTHOR]

The Optically Stimulated Luminescence (OSL) age database of Finland was established, and it includes all of the published OSL age results from different sediment sequences in Finland. The OSL database includes ~180 published OSL ages ranging from 235,000 years to 300 years; that is, from the Middle Saalian interstadial to the present. Two statistical clustering methods, K-means and model-based clustering with the package mclust, were used to analyze the internal structure of the assembled OSL data. The results of these analyses were also compared to the established Northwest European (Fennoscandian) chronostratigraphical stages. When the data were analyzed by the K-means method, the "right" number of clusters (K) was seven. The model-based clustering method (K = five) created bigger clusters for the youngest and the oldest ages compared to the K-means clusters. Both methods show that the ages followed the increasing trend from the youngest to the oldest, and the standard error of ages was constantly increasing except in the age group 70-115 ka, where the standard errors were exceptionally high. Seven clusters obtained from the age data corresponded relatively well with the number of stratigraphically established interglacials and interstadials in the late Middle and Late Pleistocene in Fennoscandia. The exceptionally large standard error of ages in the Early Weichselian age group 70-115 ka might result from mixing of heterogeneous and poorly or partly bleached mineral material from both Eemian and Early Weichselian sediment layers. The OSL-dated Middle Saalian interstadial sediments in the data support a strong stadial and interstadial variation also before the Late Pleistocene. [ABSTRACT FROM AUTHOR]

Yellowish to brownish grey, medium to fine sand-sized predominantly ellipsoidal shaped grains, here termed peloids, are studied from the core samples of ODP site 723A (latitude 18° 03.079′ N and longitude 57° 36.561′ E; water depth 808m), north-western Arabian Sea for their origin and correlation to the intensity of transporting media and paleoclimatic changes during the past 150kyrs. The total carbonate, organic matter, acid insoluble residue, magnetic susceptibility and oxygen isotope ratio data are also utilized to corroborate the above objectives. The ellipsoidal grains appeared as calcareous peloid dominantly composed of coccoliths with few micro-foraminifers tests set in micritic matrix. Dolomite rhombs are present almost in every peloids studied. Mineralogically they are dominantly made up of calcite with very small amounts of dolomite, gypsum and quartz. The predominance of coccolith plates in these peloidal grains indicates that they are probably formed from faecal matter of small herbivorous planktonic organisms that feed selectively on coccolithophorids. Alternatively, these peloids may be floccules formed by coagulation of grains during settling process. They were deposited on the sea floor below swell wave base, predominantly during the interglacial stages, when the sea water level was high. These grains were later eroded and churned by waves and tidal processes, subsequently transported (as suspension-rolling sediments) to the present site by low density turbidity current activated due to strong monsoon. The strong wave energy further caused more fragmentation of particles during the same stages. The silt to clay-sized quartz and gypsum in them indicate detrital transport by north-westerly wind originated from the adjoining Arabian Peninsula. Dolomite is authigenic origin. Although wind becomes an important agent for detrital sediment incorporation into the north-western Arabian Sea during glacial stages and higher sedimentation rate, peloidal grain contribution appears to be less affected by it. Moreover, relatively lower peloid contribution during glacial stages also indicates gradual decline of sea level and lesser intensity of monsoon generated waves and tidal processes. The millennial-scale climatic events have insignificant role in peloid contribution, its mean grain size, sorting and roundness. The peloid-based parameters show cycles of dominant climatic periodicities at Milankovitch (Precession) and sub-Milankovitch time-scales. These cycles appeared co-relatable to the local (Arabian Sea) monsoonal oscillations. [ABSTRACT FROM AUTHOR]

Although fossil assemblages from the late Early Pleistocene are very rare in Britain, the site of Westbury Cave in Somerset, England, has the potential to address this gap. The mammal fossils recovered previously from the Siliceous Member in Westbury Cave, though few in number, have hinted at an age for the deposits that is as yet unparalleled in Britain. Here, we describe the first bona fide occurrence of Hippopotamus in the British Early Pleistocene, discovered during recent reinvestigation of the Siliceous Member. The hippo fossil indicates a refined biochronological age of ca. 1.5–1.07 Ma for the Siliceous Member and a palaeoclimate that was warm and humid, which accords well with previous palaeoenvironmental inferences. A synthesis of late Early Pleistocene hippo occurrences suggests that the Siliceous Member hippo may have been part of an early colonization of north‐west Europe by these megaherbivores, possibly during MIS (Marine Oxygen Isotope Stage) 31. Alternatively, it evidences a currently cryptic northward migration during an even earlier temperate phase. In either case, the Siliceous Member is likely to represent a warm period that has not been recognized previously in the British Quaternary record. [ABSTRACT FROM AUTHOR]

This article examines the interpretation and implications of Ipswichian (Eemian) Stage temperate deposits discovered by the British Geological Survey east of the Lincoln Gap in eastern England. The fluvial deposits underlie the Southrey Terrace at Coronation Farm, Southrey and The Hermitage, Stainfield in the River Witham valley. Previously unpublished palynological analyses indicate that the temperate deposits compliment published pollen, mollusc and coleopteran assemblages from the same localities. The deposit at Southrey represents Ipswichian (=Eemian) substages Ip IIb and III, whilst that at Stainfield represents the Ip IIb Substage. The combined sequences are compared to those at neighbouring localities in the Witham and Bain-tributary valleys at Tattershall Castle and Tattershall Thorpe. The implications of the correlation of the interglacial deposits provide a re-evaluation of the River Trent-Witham terrace sequence, demonstrating that the Southrey Terrace deposits are not the equivalent of the Late Wolstonian (=Saalian) Balderton Member, but the Middle Devensian (=Weichselian) Substage Fulbeck Member, upstream of Lincoln. This implies that the River Trent was potentially aligned northwards towards the Humber before the Ipswichian Stage interglacial. The revised correlation indicates that glaciation of the region did not occur in the Middle Wolstonian (MIS 8) but during the Late Wolstonian (MIS 6) Substage. [ABSTRACT FROM AUTHOR]

Resolving marine and terrestrial records of glacial and interglacial stages has long been a challenge for Quaternary studies. We present a tephra‐based correlation for MIS 11c of a North Atlantic marine core and a British terrestrial record (Marks Tey). A varved chronology is presented for the annually laminated lake sequence at Marks Tey and the proxy data from this site are plotted on an annual timescale for the first time. This record shows clear evidence for an abrupt cold event and corresponding ecological and landscape response. Varve counting shows that the abrupt event lasted for ca 185 a but the impact on the landscape persisted for ca 560 a. The co‐occurrence of a single tephra layer in Marks Tey and ODP 980 allows these two records to be correlated. Furthermore, this synchronisation shows that the abrupt cold event in Marks Tey was coincident with a centennial‐scale cold event in ODP 980, as evidenced by an increase in Neogloboquadrina pachyderma (s) percentage. In both ODP 980 and Marks Tey the age of this abrupt event was ca 414 500 a indicating that, at this point in MIS 11c, a widespread cold event occurred in the northeastern Atlantic and the British Isles. [ABSTRACT FROM AUTHOR]

Our climate future depends on the delicate, fine balance of earth processes first elaborated on by James Croll, born 200 years ago in 1821. A childhood victim of the Scottish clearances, Croll, after following various indifferent occupations, managed to remove to the then rapidly industrialising city of Glasgow and eventually to Scotland's capital, Edinburgh. He blossomed as a most original, outside-the-box, thinker of great intellectual strength and modesty. He carried out scores of studies across a broad range of research topics, many related to the physical causes of climate change. He is well known for his astronomical theory of the ice ages, but should be much better regarded for his incisive physical insights into the central importance of feedbacks in the Earth system. Although humble, Croll was an ardent controversialist who strongly, perhaps over-strongly, always defended his corner. As well as his many accomplishments as a man of science, Croll was committed to exploring philosophical questions of theism and determinism, topics which occupied his earliest and last publications. A 'top ten' selection out of the varied subject areas that Croll tackled are explored herein, along with a brisk survey of their legacy to contemporary modelling studies and to Earth's climate future: (1) causes of climate change (1864); (2) ice-cap melt and sea-level rise (1865); (3) predicting future climates using eccentricity (1866); (4) combining orbital precession, eccentricity and obliquity (1867); (5) geological time and the date of the glacial epochs (1868); (6) geological time and denudation rates (1868); (7) ocean currents and the hemispherical temperature difference (1869); (8) feedbacks – a remarkable circumstance which led to changes of climate (1875); (9) temperature of space and its bearing on terrestrial physics (1880); (10) the causes of mild polar climates (1884). [ABSTRACT FROM AUTHOR]

Abstract Changes in the circulation of the Southern Ocean are known to have impacted global nutrient, heat, and carbon cycles during the glacial and interglacial periods of the late Pleistocene. Proxy‐based records of these changes deserve continued scrutiny as the implications may be important for constraining future change. A record of authigenic uranium from the South Atlantic has been used to infer changes in deep‐sea oxygenation and organic matter export over the past 0.5 million years. Since sedimentary uranium has the possible complication of remobilization, it is prudent to investigate the behavior of other redox‐sensitive trace metals to confidently interpret temporal changes in oxygenation. Focusing here on the exceptionally long interglacial warm period, Marine Isotope Stage (MIS) 11, we found concurrent authigenic enrichments of uranium (U) and rhenium (Re) throughout MIS 12 to 10, overall supporting prior interpretations of low‐oxygen periods. However, there are differential responses of Re and U to oxygen changes and some evidence of small‐scale Re remobilization, which may involve differences in molecular‐level reduction mechanisms. Peaks in authigenic manganese (Mn) intervening with peaks in Re and U indicate increases in porewater oxygenation which likely relate to increased Antarctic Bottom Water circulation at the onset of MIS11c and during the peak warmth of the interglacial around 400 ka.

Changes in the circulation of the Southern Ocean are known to have impacted global nutrient, heat, and carbon cycles during the glacial and interglacial periods of the late Pleistocene. Proxy‐based records of these changes deserve continued scrutiny as the implications may be important for constraining future change. A record of authigenic uranium from the South Atlantic has been used to infer changes in deep‐sea oxygenation and organic matter export over the past 0.5 million years. Since sedimentary uranium has the possible complication of remobilization, it is prudent to investigate the behavior of other redox‐sensitive trace metals to confidently interpret temporal changes in oxygenation. Focusing here on the exceptionally long interglacial warm period, Marine Isotope Stage (MIS) 11, we found concurrent authigenic enrichments of uranium (U) and rhenium (Re) throughout MIS 12 to 10, overall supporting prior interpretations of low‐oxygen periods. However, there are differential responses of Re and U to oxygen changes and some evidence of small‐scale Re remobilization, which may involve differences in molecular‐level reduction mechanisms. Peaks in authigenic manganese (Mn) intervening with peaks in Re and U indicate increases in porewater oxygenation which likely relate to increased Antarctic Bottom Water circulation at the onset of MIS11c and during the peak warmth of the interglacial around 400 ka.Key Points: Re, Mn, and U behavior consistent with porewater oxygenation variation during MIS 11Mn, U, and Re, respectively, are increasingly authigenic in ODP1094 sedimentsPotential for diagenetic effects such as remobilization of Re discussed [ABSTRACT FROM AUTHOR]

In this paper we focused on the micromorphology of the Late and Middle Pleistocene paleosols exposed in twelve loess-paleosol sequences sections in the central part of the East European Plain. Each studied paleosol complex known as Mesin (MIS 5), Kamenka (MIS 6 (8) - 7 (9)), and Inzhavino (MIS 8 (10) - 9 (11)) pedocomplexes (PCs) consists typically of two members, the earlier - main - phase of the soil development taking place during an interglacial, and the later one - at the subsequent interstadial time. Interglacial paleosols formation is associated with the thermal optimum of climatic macrocycles and corresponds to conditions close to modern in the territory under consideration. Interstadial paleosols formation characterizes the intervals within the glacial period, accompanied by an increase in heat and moisture. However, the heat supply of such intervals did not reach modern level in this region (Velichko and Morozova 2015). As follows from the analysis of the soil micromorphology over the studied area, the soil microstructure experienced notable changes under changing latitudinal zonality. During the interglacial periods clay coatings and Fe-Mn pedofeatures dominated the soil microfabric; in the south loess-paleosol sequences coatings are in negligible quantities, Fe-Mn pedofeatures decrease in amount, and carbonate pedofeatures appear instead. In the microfabric of the interstadial paleosols, Fe-Mn pedofeatures are abundant, but unlike interglacial paleosols, the coatings are rare. Basically, the coatings are humus-clayey in composition, but in the more southern sections coatings are absent.

The relative warmth of mid-to-late Pleistocene interglacials on Greenland has remained unknown, leading to debates about the regional climate forcing that caused past retreat of the Greenland Ice Sheet (GrIS). We analyze the hydrogen isotopic composition of terrestrial biomarkers in Labrador Sea sediments through interglacials of the past 600,000 y to infer millennial-scale summer warmth on southern Greenland. Here, we reconstruct exceptionally warm summers in Marine Isotope Stage (MIS) 5e, concurrent with strong Northern Hemisphere summer insolation. In contrast, "superinterglacial" MIS11 demonstrated only moderate warmth, sustained throughout a prolonged interval of elevated atmospheric carbon dioxide. Strong inferred GrIS retreat during MIS11 relative to MIS5e suggests an indirect relationship between maximum summer temperature and cumulative interglacial mass loss, indicating strong GrIS sensitivity to duration of regional warmth and elevated atmospheric carbon dioxide. [ABSTRACT FROM AUTHOR]

Bunicontro, M.P. and Marcomini, S.C., 2021. Geomorphological evolution of the Patagonian coast surrounding the Golfo Nuevo (Chubut, Argentina) during Late Quaternary: Overview and new proposal. Journal of Coastal Research, 37(3), 528–543. Coconut Creek (Florida), ISSN 0749-0208. The main contribution of this paper is a new interpretation of the geomorphological evolution of the North Patagonian coast surrounding the Golfo Nuevo from Mid-to-Late Pleistocene until present. The proposed model shows how continental and marine landforms evolved during the Late Quaternary. According to this, the Golfo Nuevo depression formed during the Middle Pleistocene (>130 ka) above previous fluvial terraces, which are attributed to different stages of the Chubut river. Several pediment types and levels were also identified: (1) flanking pediment (level 1) associated with an ancient fluvial valley; (2) convergent pediment related to a previous depression of Golfo Nuevo (level 2), both assigned to Middle Pleistocene; and (3) a littoral pediment (level 3) linked to a Holocene highstand level. The height and position of accretion marine terraces are discussed, in addition to their previous dating. It can be assumed that Golfo San Matías was flooded twice as a consequence of marine transgressions (marine isotopic stage [MIS] 5 and MIS 1). Likewise, Golfo Nuevo and Golfo San José were affected only once, during the maximum Holocene transgression (MIS 1). This paper highlights the importance of reconstructing the geomorphological evolution of a coastal area of the Patagonia as a result of a combination of changes linked to sea-level variations (mainly associated with glacio-eustasy) and climate, paleo-shorelines records, and continental landforms through Late Quaternary. The proposed geomorphological model can be considered a novelty because of the complex integration of continental and marine landforms and the study of their relative relation. [ABSTRACT FROM AUTHOR]

Limited numbers of high-resolution records predate the Last Glacial Maximum (LGM) making it difficult to quantify the impacts of environmental changes prior to peak glaciation. We examined sediments from Last Canyon Cave in the Pryor Mountains of Montana and Wyoming to construct a >45 ka environmental record from pollen and stable isotope analysis. Artemisia pollen was hyper-abundant at the beginning of the record. Carbon isotope values of bulk organic matter (>40 ka) showed little variation (-25.3 ± 0.4‰) and were consistent with a arid C3 environment, similar to today. After 40 cal ka BP, Artemisia pollen decreased as herbaceous taxa increased toward the LGM. A significant decrease in δ13C values from 40–30 cal ka BP (~1.0‰) established a new baseline (-26.6 ± 0.2‰), suggesting cooler, seasonally wetter conditions prior to the LGM. These conditions persisted until variation in δ13C values increased significantly with post-glacial warming, marked by two spikes in values at 14.4 (-25.2‰) and 13.5 cal ka BP (-25.4‰) before δ13C values dropped to their lowest values (-26.9 ± 0.2‰) at the onset of the Younger Dryas (12.8 ka). These results provide insights into late Pleistocene conditions and ecological change in arid intermontane basins of the Rocky Mountains. [ABSTRACT FROM AUTHOR]

Abstract We present results from a well‐dated sediment core on the Pacific‐Antarctic Ridge (PAR) that document a ∼15 cm thick layer of basaltic ash shards that precedes the penultimate deglaciation (Termination 2). The glasses have MORB composition consistent with an axial source and their morphologies are typical of pyroclastic deposits created by submarine volcanism. The ash layer was deposited ∼7 km from the PAR axis, a distance that implies buoyant plumes lofted debris high into the water column with subsequent fallout to the core location. We infer plume rise height using grain settling velocities, the water depth at the core site, and deep ocean current speeds from ARGO floats. Rise heights of 1.5 km or less require unrealistically large current speeds to transport grains to the core site. Instead, the data are consistent with a plume rise height of at least 2 km, implying that T2 was an interval of anomalous volcanism along this segment of the PAR. The timing and duration of the ash deposit is consistent with glacial‐interglacial modulation of ridge magmatism. Volcaniclastic records from additional locations will be necessary to assess whether the PAR record is a rare find or it is representative of mid‐ocean ridge volcanism during glacial terminations.

Planktonic foraminifera are good indicators of age and paleoclimatic variations, being widely used in relative dating, sedimentary basin analysis and stratigraphic correlations. In the lower slope of the Pelotas Basin there is a difficulty to develop paleoclimatic models due to the low quality of the fossil remains, which can be easily dissolved or remobilized, but the low preservation, when well quantified, can become a paleoceanographic proxy, since the non-preservation occurs due to measurable environmental changes. The goal of this study is to identify variations of the planktonic foraminifera fauna and the preservation of CaCO3 recorded in two cores in the Pelotas Basin and to relate them to the paleoceanographic changes occurred in the region. The cores were collected by the oceanographic expedition Geomar VII, on the lower slope of the Pelotas Basin. The samples were prepared with the standard methods for paleomicrontological analysis. The basic paleoclimatic zoning was elaborated based on the presence or absence of carbonate and the occurrence of species of the Globorotalia menardii plexus, whose disappearances and reappearances are related to climatic oscillations of glacial and interglacial intervals. Since there is no significant textural change in the facies, the two cores were subdivided into five intervals, based on the presence or absence of foraminifera (pelagic volume) and the presence or absence of the G menardii plexus. The intervals with good carbonate preservation were attributed to the Marine Isotopic Stages (MIS) 5 and 1. Carbonate-free intervals were attributed to an upward displacement of the lysocline and the Carbonate Compensation Depth (CCD). At the end of the Pleistocene, a downward migration of the lysocline and CCD was registered as a function of the transition from the MIS 2 to the MIS 1 or by the Pleistocene/Holocene boundary. Finally, the boundary of the Y and Z biozones was identified between 0.4 and 0.3 m in one core of the lower slope of the Pelotas Basin

The Lanshanmiao (LSM) Palaeolithic site, which was excavated in the summer of 2017 by the Zhejiang Provincial Institute of Cultural Relics and Archaeology, is the only excavated palaeolithic site in central Zhejiang Province to date. Luminescence dating methods, including optical stimulated luminescence (OSL) and thermal transfer OSL (TT-OSL) for quartz and post-infrared (IR) stimulated luminescence (pIRIR290) for feldspar, were used to determine the age of the LSM site. The results showed that the LSM section developed before 145.5 ± 12.5 ka and ended after 17.1 ± 1.0 ka. The TT-OSL dating of samples NJU2576 and NJU2615 showed that palaeolithic artifact-bearing layer was between 150 and 100 ka in age. The age range of the palaeolithic layer mainly corresponded to the transition between Marine Isotope Stage (MIS) 6 and MIS5. Our study showed that hominins prominently occupied the LSM site during the glacial and interglacial stages, when it exhibited a floodplain environment. [ABSTRACT FROM AUTHOR]

The Jigongshan (JGS) Paleolithic site in the middle reaches of the Yangtze River has two different cultural layers, namely, the upper (flake-tool industry) and lower (cobble-tool industry) cultural layers. JGS site is also among the few upper Paleolithic sites in the middle reaches of the Yangtze River with an absolute age. Peking University has performed a preliminary 14C dating at the site and found that the upper culture layer is approximately 10–20 ka, whereas the lower layer is older than 50 ka. To date the lower culture layer precisely, the standard quartz single-aliquot regenerative (SAR) dose-based optically stimulated luminescence (OSL) and thermally transferred OSL (TT-OSL) methods were used in this study. Results showed that the age of the upper culture layer is approximately 23 ± 2–38 ± 3 ka, whereas that of the lower culture layer is approximately 115 ± 9–149 ± 9 ka. The 14C and OSL dating methods showed huge differences in their results for the lower culture layer. Based on our dating results, we propose that the main part of the upper culture layer corresponds to the late MIS 3 to the early MIS 2 stages during the glacial period in L 1 unit in the Chinese loess sequence, whereas the lower culture layer corresponds to the late MIS 6 and the early MIS 5 stages during both glacial and interglacial periods in the upper L 2 and the lower S 1 units. A cultural gap of nearly 100 ka was observed between these two cultural layers; this gap is larger than what was expected. [ABSTRACT FROM AUTHOR]

Ice core data have shown that atmospheric CO2 concentrations during interglacials were lower before the Mid‐Brunhes Event (MBE, ~430 ka), than after the MBE by around 30 ppm. To explain such a difference, it has been hypothesized that increased bottom water formation around Antarctica or reduced Atlantic Meridional Overturning Circulation (AMOC) could have led to greater oceanic carbon storage before the MBE, resulting in less carbon in the atmosphere. However, only few data on possible changes in interglacial ocean circulation across the MBE have been compiled, hampering model‐data comparison. Here we present a new global compilation of benthic foraminifera carbon isotopic (δ13C) records from 31 marine sediment cores covering the last 800 ka, with the aim of evaluating possible changes of interglacial ocean circulation across the MBE. We show that a small systematic difference between pre‐ and post‐MBE interglacial δ13C is observed. In pre‐MBE interglacials, northern source waters tend to have slightly higher δ13C values and penetrate deeper, which could be linked to an increased northern sourced water formation or a decreased southern sourced water formation. Numerical model simulations tend to support the role of abyssal water formation around Antarctica: Decreased convection there associated with increased sinking of dense water along the continental slopes results in increased δ13C values in the Atlantic in agreement with pre‐MBE interglacial data. It also yields reduced atmospheric CO2 as in pre‐MBE records, despite a smaller simulated amplitude change compared to data, highlighting the need for other processes to explain the MBE transition. Key Points: Sediment core data show a systematic oceanic δ13C difference between interglacials before and after the Mid‐Brunhes Event (MBE)Model simulations show that it can be partly due to ocean circulation changesBut ocean circulation change can only account for 1/3rd of the measured atmospheric CO2 change between interglacials over the MBE [ABSTRACT FROM AUTHOR]

This article examines the interpretation and implications of certain conifer - dominated pollen assemblages recorded in lowland England, at sites glaciated during the Middle Pleistocene Wolstonian Stage. Such assemblages indicate the absence of severely cold-climate during a predominantly cold period and the presence of northern temperate boreal-type forest. The unambiguous stratigraphical position of the sequences provides evidence of climatic change during the late Middle Pleistocene. Nine sequences are considered, six in the English West Midlands, and three in eastern England. Evidence for temperate climate, and at some, subsequent cold-climate (periglacial) conditions is present within deposits pre-dating Wolstonian-age glacial deposits. In the Midlands, Wolston Formation glacial sediments overlie deposits of a pre-existing river system, the Baginton Formation. The latter accumulated during the transition from boreal to subarctic conditions. Evidence is based on sequences at Mathon, Waverley Wood, Brandon, Brooksby, Witham-on-the-Hill, High Lodge and Barnham. Since the Wolstonian glaciation occurred during the Late Wolstonian Substage (= Late Saalian, Marine Isotope Stage [MIS] 6), the Baginton Formation must span the MIS 7/6 boundary. Reinterpretation of the sequences indicates that the temperate continental climate interval, termed here the Waverley Wood temperate event, potentially represents the latter part of MIS 7 (Substages 7a-c, or 7e). This correlation is supported by comparison with sites on the near Continent. The implications of these conclusions are presented. [ABSTRACT FROM AUTHOR]

Asexual hybrids are important model organisms for addressing questions in evolution and ecology, especially for understanding the role of hybridization in speciation. They are rare in nature and several hypotheses have been suggested to explain this. We use an asexual fish, the Amazon molly (Poecilia formosa), to establish the area in which it was formed via hybridization 125 000 years ago. Using species distribution models and climate models for the Last Interglacial (LIG) we found that model projections to the LIG show a similar map to the present climate model and parental species potentially overlapped in a relatively small area near Tampico, Mexico. This makes P. formosa one of a few hybrid species for which we know the parental species, the time of hybridization, and likely the place of hybridization. Based on the small area of overlap, our data is in agreement with the idea that asexual hybrids may be rare not because they are evolutionary dead ends but are formed rarely. [ABSTRACT FROM AUTHOR]

The Arctic climate was warmer than today at the last interglacial and the Holocene thermal optimum. To reveal the impact of past climate-warming events on the demographic history of an Arctic specialist, we examined both mitochondrial and nuclear genomic variation in the collared lemming (Dicrostonyx torquatus, Pallas), a keystone species in tundra communities, across its entire distribution in northern Eurasia. The ancestral phylogenetic position of the West Beringian group and divergence time estimates support the hypothesis of continental range contraction to a single refugial area located in West Beringia during high-magnitude warming of the last interglacial, followed by westward recolonization of northern Eurasia in the last glacial period. The West Beringian group harbors the highest mitogenome diversity and its inferred demography indicates a constantly large effective population size over the Late Pleistocene to Holocene. This suggests that northward forest expansion during recent warming of the Holocene thermal optimum did not affect the gene pool of the collared lemming in West Beringia but reduced genomic diversity and effective population size in all other regions of the Eurasian Arctic. Demographic inference from genomic diversity was corroborated by species distribution modeling showing reduction in species distribution during past climate warming. These conclusions are supported by recent paleoecological evidence suggesting smaller temperature increases and moderate northward forest advances in the extreme northeast of Eurasia during the Late Pleistocene-to- Holocene warming events. This study emphasizes the importance of West Beringia as a potential refugium for cold-adapted Arctic species under ongoing climate warming. [ABSTRACT FROM AUTHOR]

Aim: To investigate cerrado responses to glacial–interglacial climate change and the potential for connective rain forest corridors between the Atlantic Coastal Forest and Amazonian rain forest. Location: The crater lake of Serra Negra (18 °S, 46 °W) in Minas Gerais, Brazil. Taxon: 117 fossil pollen types, 22 non‐pollen palynomorphs were documented. Methods: We recovered 7.82 m of sediment from the lake, and analysed fossil pollen at 62 depth intervals throughout the core. We derived a chronology based on radiocarbon dating with simple rate extrapolation to the base of the core. Results: The c. 90,000‐year fossil record showed a trend towards cooler climates at the Last Glacial Maximum (LGM), but interstadial warming coupled with reduced evaporative stress allowed the expansion of woodlands under cool, moist conditions. Cool‐adapted trees were most abundant between c. 67,000 and 48,000 years ago. A cool cerrado‐like environment marked full glacial conditions between c. 48,000 and 34,000 years ago. The peak of the LGM between c. 34,000 and 17,000 years ago is inferred to have been dry as no sediment accumulated in the system. Main conclusions: Expanded ranges of cold‐tolerant forest taxa led to establishment of a series of assemblages without modern analogue. A system characteristic of modern cerrado was rare in the history of this site. Multiple forest expansions were observed, each differing in composition. The periods of forest abundance at Serra Negra were not temporally aligned with forest expansion in the Atlantic Coastal Forest, and did not provide a continuous corridor of similar forest that connected the cerrado to the Atlantic Coastal Forest. [ABSTRACT FROM AUTHOR]

A number of interglacial sections discovered in the eastern part of Lithuania and suggested as Snaigupėlė Interglacial were attributed to the Saalian Complex Stage of Middle Pleistocene. However, the exact stratigraphical position and correlation of these interglacial sections are still arguable. Recent investigations were performed to get a clearer insight into the stratigraphy and sedimentation palaeoenvironment of the Snaigupėlė Interglacial sediments outcropping in Buivydžiai section and included complex proxies: pollen, plant macrofossils, diatoms, loss on ignition, magnetic susceptibility and optically stimulated luminescence dating. Interglacial sediments occur at the lowermost part of the exposure and reach more than 7 m thick. Palaeobotanical investigations confirm deposition of studied sediments during the different climatic stages of the interglacial. An attempt at correlation between the Buivydžiai section vegetational changes with vegetational succession obtained from north-central Europe allowed finding out some similarities with the Schöningen/Lublinian Interglacial. The OSL dating results do not contradict such a proposition as the two sand samples lying below the interglacial gyttja show sedimentation of this layer during the 300.5 ± 20.9 ka and 317.3 ± 21.8 ka time or MIS 9. However, recently obtained data are insufficient for grounding the correlation of studied section. Certainly, additional chronostratigraphic investigations would be valuable and may contribute to the solution of the sediment age and correlation problem. [ABSTRACT FROM AUTHOR]

Throughout the Phanerozoic, numerous well-preserved fossiliferous sites have provided valuable insights into the evolution of ecosystems and organisms. Among these sites, the Lontras Shale Lagerstätte (LSL) within the Lontras Member in southern Brazil stands out as a rare glimpse into Carboniferous ecosystems of western Gondwana. The LSL is renowned for its diverse array of well-preserved fossils like insects, wood, fishes, larval cases, and poriferans, with different types of preservational pathways. Moreover, the Lontras Member is considered a maximum flooding surface that marks an interglacial warming peak of the final Late Paleozoic Ice Age, highlighting its paleoclimatological and paleogeographical relevance. However, the occurrence of fossils within the extensive Lontras Member is restricted to a few sites, raising questions about the factors influencing this constrained lateral and vertical distribution. Through meticulous literature review, this study aims not only to solidify the understanding of the Lontras Member's lithostratigraphy and paleontology but also to explore its broader implications and paleoenvironmental significance. We propose a comprehensive stratigraphic section for the Lontras Member, integrating local and regional sections from Santa Catarina and Paraná States, surveying paleontological sites and fossils exhaustively. By examining two additional fossil-rich sites in addition to the Lagerstätte outcrop, and analyzing vertical and horizontal distributions of the Member, we thoroughly explore the methodological, paleoenvironmental, and taphonomic factors that restricts this fossil record. This analysis extends beyond comparisons with paleontological insights from other units, locations, and Lagerstätten, encompassing modern analogous environments. The methodological biases are tied to stratigraphic focus, fieldwork scale, fossil size, and weathering degree of outcrops, constraining new fossil discoveries. Paleobiological and paleoclimatological factors, like transitional climatic conditions, limited organism diversity, inhospitable deep environments distant from the coast, and anoxic bottoms impact organism distribution and fossil recovery. The fossil transportability and the compositional resilience under widespread anoxia contributed as preservational constraints. While the LSL offers unique conditions for the proliferation and preservation of organisms, limiting the taphonomic window, facies of more energetic depositional conditions in other Lontras Member sites is more likely to harbor fossils, particularly transportable fragments and disarticulated pieces of chitinophosphatic or phosphatic composition. Addressing these biases unveils insights into flourishing ecosystems and organisms during this specific time period. [Display omitted] • The Lontras Member, a stratigraphic landmark, is vertically and horizontally extensive. • Fossil distribution in this unit is constrained to a Lagerstätte and two other sites. • Collection biases, paleobiological and taphonomic factors limit the fossil occurrence. • The taphonomic window of this Lagerstätte is restricted to this outcrop. • Transportable chitin/phosphatic bioclasts have better recovery odds in this unit. [ABSTRACT FROM AUTHOR]