Late Quaternary Paleoenvironmental Reconstruction, Using Benthic Foraminifera and Ostracoda, of Marine Sedimentary Beds On the Southern Coast of Laizhou Bay, Bohai Sea, China

2018 ◽  
Vol 48 (2) ◽  
pp. 87-99 ◽  
Author(s):  
Xiaohui Cui ◽  
Shoujun Li ◽  
Hua Xu ◽  
Zhuo Zhang ◽  
Xiuli Zhao ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Bohai Sea ◽  
Late Quaternary ◽  
Middle Pleistocene ◽  
Small Scale ◽  
Laizhou Bay ◽  
Benthic Foraminifers ◽  
The Holocene ◽  
Subtidal Environment ◽  
Late Middle Pleistocene

Abstract Extensive studies of Quaternary transgressions have been conducted in Bohai Sea, but debates continue regarding the sedimentary evolution and timing of transgressions, especially in the Pleistocene section. Benthic foraminifers and ostracodes from three boreholes (GK138, GK111, GK95) at Laizhou Bay, Bohai Sea, were utilized to interpret the paleoenvironments of deposition and elucidate the coastal response to global sea-level changes since the late Quaternary. Benthic foraminiferal species identified included 32 species from 15 genera; ostracodes included 28 species from 16 genera. Three marine sedimentary beds were recognized based on sedimentary characteristics, down-core changes in environmental proxies (benthic foraminifers and ostracodes), accelerator mass spectrometry (AMS) 14C, and optically stimulated luminescence (OSL) dates. These three beds were interpreted as: marine sedimentary bed 3 (M3), deposited in the late-middle Pleistocene; marine sedimentary bed 2 (M2), deposited during the late Pleistocene; and marine sedimentary bed 1 (M1), deposited during the Holocene. Three microfossil assemblages were identified, all indicating nearshore conditions. Assemblage III indicated a fluvially influenced or paralic environment during a relatively small-scale late-middle Pleistocene transgression that produced bed M3. Assemblage II indicates an intertidal-subtidal environment where bed M2 was deposited during the late Pleistocene transgression. Assemblage I indicates somewhat more marine influence in a subtidal environment where bed M1 was deposited during the Holocene marine transgression.

Denisovan DNA in Late Pleistocene sediments from Baishiya Karst Cave on the Tibetan Plateau

Science ◽  
2020 ◽  
Vol 370 (6516) ◽  
pp. 584-587
Author(s):  
Dongju Zhang ◽  
Huan Xia ◽  
Fahu Chen ◽  
Bo Li ◽  
Viviane Slon ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Amino Acid ◽  
Tibetan Plateau ◽  
Late Pleistocene ◽  
Amino Acid Substitution ◽  
Middle Pleistocene ◽  
The Tibetan Plateau ◽  
Karst Cave ◽  
Late Middle Pleistocene

A late Middle Pleistocene mandible from Baishiya Karst Cave (BKC) on the Tibetan Plateau has been inferred to be from a Denisovan, an Asian hominin related to Neanderthals, on the basis of an amino acid substitution in its collagen. Here we describe the stratigraphy, chronology, and mitochondrial DNA extracted from the sediments in BKC. We recover Denisovan mitochondrial DNA from sediments deposited ~100 thousand and ~60 thousand years ago (ka) and possibly as recently as ~45 ka. The long-term occupation of BKC by Denisovans suggests that they may have adapted to life at high altitudes and may have contributed such adaptations to modern humans on the Tibetan Plateau.

Late Quaternary Climate and Vegetation of the Sudanian Zone of Northeast Nigeria

2002 ◽  
Vol 58 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Ulrich Salzmann ◽  
Philipp Hoelzmann ◽  
Irena Morczinek
Keyword(s):  
Environmental History ◽  
Late Pleistocene ◽  
Late Quaternary ◽  
Climatic Conditions ◽  
Lake Levels ◽  
The Holocene ◽  
Quaternary Climate ◽  
History Of ◽  
Sudanian Zone ◽  
Humid Period

AbstractThe Lake Tilla crater lake in northeastern Nigeria (10°23′N, 12°08′E) provides a ca. 17,000 14C yr multiproxy record of the environmental history of a Sudanian savanna in West Africa. Evaluation of pollen, diatoms, and sedimentary geochemistry from cores suggests that dry climatic conditions prevailed throughout the late Pleistocene. Before the onset of the Holocene, the slow rise in lake levels was interrupted by a distinct dry event between ca. 10,900 and 10,500 14C yr B.P., which may coincide with the Younger Dryas episode. The onset of the Holocene is marked by an abrupt increase in lake levels and a subsequent spread of Guinean and Sudanian tree taxa into the open grass savanna that predominated throughout the Late Pleistocene. The dominance of the mountain olive Olea hochstetteri suggests cool climatic conditions prior to ca. 8600 14C yr B.P. The early to mid-Holocene humid period culminated between ca. 8500 and 7000 14C yr B.P. with the establishment of a dense Guinean savanna during high lake levels. Frequent fires were important in promoting the open character of the vegetation. The palynological and palaeolimnological data demonstrate that the humid period terminated after ca. 7000 14C yr B.P. in a gradual decline of the precipitation/evaporation ratio and was not interrupted by abrupt climatic events. The aridification trend intensified after ca. 3800 14C yr B.P. and continued until the present.

scholarly journals Exploring the phylogeography and population dynamics of the giant deer ( Megaloceros giganteus ) using Late Quaternary mitogenomes

2021 ◽  
Vol 288 (1950) ◽  
Author(s):  
Alba Rey-Iglesia ◽  
Adrian M. Lister ◽  
Paula F. Campos ◽  
Selina Brace ◽  
Valeria Mattiangeli ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Last Glacial Maximum ◽  
Late Pleistocene ◽  
Late Quaternary ◽  
Glacial Maximum ◽  
Climatic Fluctuations ◽  
The Holocene ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Late Quaternary climatic fluctuations in the Northern Hemisphere had drastic effects on large mammal species, leading to the extinction of a substantial number of them. The giant deer ( Megaloceros giganteus ) was one of the species that became extinct in the Holocene, around 7660 calendar years before present. In the Late Pleistocene, the species ranged from western Europe to central Asia. However, during the Holocene, its range contracted to eastern Europe and western Siberia, where the last populations of the species occurred. Here, we generated 35 Late Pleistocene and Holocene giant deer mitogenomes to explore the genetics of the demise of this iconic species. Bayesian phylogenetic analyses of the mitogenomes suggested five main clades for the species: three pre-Last Glacial Maximum clades that did not appear in the post-Last Glacial Maximum genetic pool, and two clades that showed continuity into the Holocene. Our study also identified a decrease in genetic diversity starting in Marine Isotope Stage 3 and accelerating during the Last Glacial Maximum. This reduction in genetic diversity during the Last Glacial Maximum, coupled with a major contraction of fossil occurrences, suggests that climate was a major driver in the dynamics of the giant deer.

scholarly journals Dietary responses of Sahul (Pleistocene Australia–New Guinea) megafauna to climate and environmental change

Paleobiology ◽  
2017 ◽  
Vol 43 (2) ◽  
pp. 181-195 ◽  
Author(s):  
Larisa R. G. DeSantis ◽  
Judith H. Field ◽  
Stephen Wroe ◽  
John R. Dodson
Keyword(s):  
Late Pleistocene ◽  
Population Biology ◽  
Late Quaternary ◽  
New Guinea ◽  
Middle Pleistocene ◽  
Dental Microwear ◽  
Southeastern Australia ◽  
Climate And Environmental Change ◽  
Arid Conditions ◽  
Monitor Lizards

AbstractThroughout the late Quaternary, the Sahul (Pleistocene Australia–New Guinea) vertebrate fauna was dominated by a diversity of large mammals, birds, and reptiles, commonly referred to as megafauna. Since ca. 450–400Ka, approximately 88 species disappeared in Sahul, including kangaroos exceeding 200kg in size, wombat-like animals the size of hippopotamuses, flightless birds, and giant monitor lizards that were likely venomous. Ongoing debates over the primary cause of these extinctions have typically favored climate change or human activities. Improving our understanding of the population biology of extinct megafauna as more refined paleoenvironmental data sets become available will assist in identifying their potential vulnerabilities. Here, we apply a multiproxy approach to analyze fossil teeth from deposits dated to the middle and late Pleistocene at Cuddie Springs in southeastern Australia, assessing relative aridity via oxygen isotopes as well as vegetation and megafaunal diets using both carbon isotopes and dental microwear texture analyses. We report that the Cuddie Springs middle Pleistocene fauna was largely dominated by browsers, including consumers of C4 shrubs, but that by late Pleistocene times the C4 dietary component was markedly reduced. Our results suggest dietary restriction in more arid conditions. These dietary shifts are consistent with other independently derived isotopic data from eggshells and wombat teeth that also suggest a reduction in C4 vegetation after ~45 Ka in southeastern Australia, coincident with increasing aridification through the middle to late Pleistocene. Understanding the ecology of extinct species is important in clarifying the primary drivers of faunal extinction in Sahul. The results presented here highlight the potential impacts of aridification on marsupial megafauna. The trend to increasingly arid conditions through the middle to late Pleistocene (as identified in other paleoenvironmental records and now also observed, in part, in the Cuddie Springs sequence) may have stressed the most vulnerable animals, perhaps accelerating the decline of late Pleistocene megafauna in Australia.

scholarly journals A geological concept of the map sheet Rønde based on dynamic structures

1987 ◽  
Vol 8 ◽  
pp. 1-59
Author(s):  
Kaj Strand Petersen ◽  
Leif Aabo Rasmussen
Keyword(s):  
Late Pleistocene ◽  
Middle Pleistocene ◽  
The South ◽  
The Holocene ◽  
Dynamic Structures ◽  
Geological Concept ◽  
Weichselian Glaciation ◽  
Glacial Advance

During the mapping of the map sheet Rønde 1315 II an important kineto-stratigraphical frame for the Late Middle Weichselian in the central part of Denmark was demonstrated. Quaternary units are deposited on Paleogene sediments consisting of clayey Eocene-Paleocene strata to the southwest and Lower Paleocene-Danian limestone to the northeast. Middle Pleistocene till units are found as erosional remnants on the Prequaternary surface. The Late Pleistocene deposits are described within the kineto-stratigraphical concept, showing an older unit related to a glacial advance from the northeast and a younger one from the south, both belonging to the Late Middle Weichselian glaciation. Prominent extramarginal outwash sand deposits cover - the central part of the map sheet as a part of the drift unit from the south. The low-lying areas have beeen covered by the sea during the Holocene from the transgression in Early Atlantic up to the end of Subboreal. In the Subatlantic, freshwater deposits were formed, later covered by peat.

Vegetation at the northern pole of cold during the climate extremes of the late Pleistocene: fossil records from the Batagay mega thaw slump, Yakutia

2020 ◽  
Author(s):  
Frank Kienast ◽  
Kseniia Ashastina ◽  
Svetlana Kuzmina ◽  
Natalya Rudaya
Keyword(s):  
Northern Hemisphere ◽  
Late Pleistocene ◽  
Late Quaternary ◽  
Plant Cover ◽  
Climate Extremes ◽  
Environmental Stability ◽  
Middle Pleistocene ◽  
Last Interglacial ◽  
Large Herbivores ◽  
Steppe Belt

<p>The Batagay mega slump is the largest active thaw slump on the planet. Enormously rapid thermal erosion gave access to permafrost sediments that deposited since the Middle Pleistocene. Permafrost is an excellent medium for the preservation of ancient organic matter. The Batagay exposure is well known for some spectacular findings of Pleistocene megaherbivore carcasses including the youngest steppe bison found in Eurasia so far, dated to 8.2 ka BP. The extraordinarily long sequence of Pleistocene deposits in Batagay is therefore an excellent archive of the palaeoenvironmental history in the Yana highlands - a region with uniquely stable cold-continental climate known as the pole of cold in the northern hemisphere. This region is regarded as refugial area for extrazonal steppe plants and now extinct large grazers together constituting the Pleistocene mammoth steppe, which covered vast areas in high and mid latitudes of the northern hemisphere during cold stages. Modern vegetation around the study site consists of light taiga mainly composed of larch, shrub alder, shrub birches and stone pine. To understand the processes that resulted in the demise of Pleistocene megafauna and in the biological turnover during the late Quaternary, we reconstructed vegetation and environmental conditions during the two climate extremes of the late Pleistocene, the onset of the last glacial maximum and the last interglacial using remains of plants and insects preserved in organic-rich material. The results from studies of plant material gathered in a fossil ground squirrel nest suggest that grassland vegetation corresponding to modern meadow steppes in Central Yakutia and northern Mongolia existed in the study area during the last cold stage. During the last interglacial, open coniferous woodland similar to modern larch taiga was the primary vegetation at the site. Abundant charcoal indicates wildfire events during the last interglacial. Zoogenic disturbances of the local vegetation were indicated by the presence of ruderal plants, especially by the abundant nitrophytic <em>Urtica dioica</em>, suggesting that the area was an interglacial refugium for large herbivores. Meadow steppes, which formed the primary vegetation during cold stages and provided potentially suitable pastures for herbivores, were a significant constituent of the plant cover in the Yana Highlands also under the full warm stage conditions of the last interglacial. Consequently, meadow steppes occurred in the Yana Highlands during the entire investigated timespan of the Pleistocene documenting a remarkable environmental stability. The documented fossil record also proves that modern steppe occurrences in the Yana Highlands did not establish as late as in the Holocene, as suggested by some scholars, but instead are relicts of a formerly continuous steppe belt extending from Central Siberia to Northeast Yakutia during the Pleistocene.</p>

Electron-Microbeam investigation of late quaternary sand sediments from the lagoon of venice (Italy)

1992 ◽  
Vol 50 (2) ◽  
pp. 1750-1751
Author(s):  
Maurizio Bonardi
Keyword(s):  
Late Pleistocene ◽  
Adriatic Sea ◽  
Late Quaternary ◽  
Venice Lagoon ◽  
Lagoon Of Venice ◽  
Quaternary Sediments ◽  
The Holocene ◽  
Venetian Lagoon ◽  
Preliminary Study ◽  
Clay Layers

Electron probe microanalysis (EPMA) has been used to investigate the mineral assemblage of sand samples from the Venice Lagoon Quaternary sediments. These sediments consist mainly of sand, silt and clay layers with some peat lenses. The boundary between the Holocene and Late-Pleistocene is marked by an overconsolidated layer of clay, related to the origin of the Venetian Lagoon. Because in some area of the basin this clay layer has been eroded away it is not always possible to accurately define the limit between the Holocene and Pleistocene sedimentations.Seventeen continuous cores collected for geotechnical purposes along the offshore sandy bar that separates the Lagoon of Venice from the open Adriatic Sea, were available for this investigation. The cores 25 to 30 m long included the Holocene and Late-Pleistocene sediments. For this preliminary study about 130 sand samples were selected at different depth in order to characterize the various levels of the sediments, recognize and define possible correlations between the layers in the 17 cores and, most important, define the boundary between the Holocene and Pleistocene sediments.

scholarly journals The Forming Age and the Evolution Process of the Brine Lithium Deposits in the Qaidam Basin Based on Geochronology and Mineral Composition

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhe Ma ◽  
Fengqing Han ◽  
Tianyuan Chen ◽  
Lei Yi ◽  
Xiaohang Lu ◽  
...  
Keyword(s):  
Mineral Composition ◽  
Late Pleistocene ◽  
Salt Lake ◽  
Qaidam Basin ◽  
Ore Deposits ◽  
Osl Dating ◽  
Tectonic Activity ◽  
Middle Pleistocene ◽  
The Holocene ◽  
Climatic Environment

Lithium ore deposits are divided into pegmatite and brine deposits. The Puna Plateau and the Qinghai–Tibetan Plateau (QTP) are home to the most abundant brine lithium deposits worldwide. Very few studies have investigated the chronology of brine lithium deposits. This paper reports the Optically Stimulated Luminescence (OSL) dating measurements for typical brine lithium deposits at QTP, including East Taijnar Salt Lake, West Taijnar Salt Lake, and Yiliping Salt Lake in the central Qaidam Basin. Combining the results of OSL dating with previous studies and mineral composition obtained by X-ray diffraction analysis (XRD), this study summarizes the age and characteristics of the climatic environment during the formation of brine lithium deposits in the Qaidam Basin. The main results are: 1) Brine lithium deposits in the Qaidam Basin began to form since 40 ka. Brine lithium deposits in South America formed during the middle Pleistocene and late Pleistocene, and are older than the deposits in the Qaidam Basin. The lithium deposits of Tibet formed around 4 ka, are the youngest. 2) The climate in East Taijnar Salt Lake and West Taijnar Salt Lake was extremely cold and dry during 27–4.6 ka, with a relatively humid climatic condition at ∼10 ka. After 4.6 ka, the environment was comparatively more humid around both lakes. Yiliping Salt Lake had a dry climate since 38.09 ka, and the climate in the Three Lakes area is mainly controlled by the westerlies in the Holocene; and 3) East Taijnar Salt Lake, West Taijnar Salt Lake and Yiliping Salt Lake were located in the same secondary basin during the late Pleistocene. However, tectonic activity around 40 ka led to the evolution of Yiliping Salt Lake into an independent basin. East Taijnar Salt Lake and West Taijnar Salt Lake separated around 27 ka, and then deposited the lower salt layers until the Holocene. The substantial amount of detrital minerals that the Nalinggele River brought during the Holocene led to a brief desalination of East Taijnar Salt Lake. The upper salt layer was deposited in East Taijnar Salt Lake and West Taijnar Salt Lake during this period due to the extremely dry climate.

scholarly journals Rediscovering Lutra lutra from Grotta Romanelli (southern Italy) in the framework of the puzzling evolutionary history of Eurasian otter

PalZ ◽  
2021 ◽  
Author(s):  
Beniamino Mecozzi ◽  
Alessio Iannucci ◽  
Fabio Bona ◽  
Ilaria Mazzini ◽  
Pierluigi Pieruccini ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Evolutionary History ◽  
Middle Pleistocene ◽  
Lutra Lutra ◽  
Multidisciplinary Research ◽  
Historical Collections ◽  
Eurasian Otter ◽  
History Of ◽  
Early Late ◽  
Late Middle Pleistocene

AbstractA river otter hemimandible has been rediscovered during the revision of the historical collections of G.A. Blanc from Grotta Romanelli, complementing the ongoing multidisciplinary research fieldwork on the site. The specimen, recovered from the level G (“terre rosse”; early Late Pleistocene or late Middle Pleistocene), is here assigned to Lutra lutra. Indeed, morphological and morphometric comparisons with other Quaternary Lutrinae fossils from Europe allow to exclude an attribution to the relatively widespread and older Lutra simplicidens, characterized by distinctive carnassial proportions. Differences with Cyrnaonyx antiqua, which possessed a more robust, shellfish-feeding dentition, support the view of a successful niche repartition between the two species during the late Middle to Late Pleistocene of Europe. The occurrence of Lutra lutra from the “terre rosse” of Grotta Romanelli suggests deep modifications of the landscapes due to the ecological adaptation of the taxon, and indicates that the Eurasian otter spread into Europe at the Middle–Late Pleistocene transition.

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