Search Results (17)

The origin of humans on Earth is closely linked to understanding how ancient populations dispersed into adjacent territories. Traditionally, studies have identified landscape and climatic changes as the primary factors in this dispersal. However, we propose that regional tectonic and geodynamic factors also played a significant role in shaping these movements. To analyze this phenomenon, we employed several primary methods, including radiometric dating, magnetostratigraphy, paleomagnetic correlation, isotope–oxygen analysis, tectonothermal studies, gravity mapping, paleobiogeographic assessment, lithofacies analysis, and event and cyclic stratigraphy. Our research indicates that the Akchagylian hydrospheric maximum, which reached up to +200 m, significantly limited the early dispersal of hominins from Africa to Eurasia. The migration corridor was shaped by tectonic activity between the Dead Sea Transform and the boundary of the Mesozoic Terrane Belt carbonate platform. We argue that, during the early stages of hominin evolution in East Africa, the Levantine Corridor (LC) had not yet developed into an optimal route for dispersal, either tectonically or paleogeographically. Suitable habitats for early hominins emerged only after the regression at the end of the Middle Gelasian, around two million years ago, when sea level fell by approximately 200 m, leading to the dissection of the coastal high plateau of the Eastern Mediterranean. We therefore suggest that the LC became established only after the termination of the Akchagylian transgression and the subsequent landscape reconfiguration of the Eastern Mediterranean. Our integrated analysis, combining paleomagnetic, structural, tectonic, and event stratigraphy data, indicates that the age of the renowned ‘Ubeidiya site in northern Israel is several thousand years older than previously thought. This paleogeographic impact had not been considered in earlier studies. Considering the diverse and complex factors that governed hominin dispersal from Africa into Eurasia within this multifaceted region, we propose that the scope of research should be broadened. Our detailed study of the Carmel area, located northeast of the Levantine Corridor and influenced by it during the Pleistocene, indicates that this region was inundated during the early phases of hominin migration out of Eastern Africa. Besides this, we have conducted an integrated geological–geophysical landscape analysis of the central part of the Israeli coastal plain. Full article

Anemone altaica Fisch. ex C. A. Mey., a component of the tertiary boreo-nemoral vegetation complex, exhibits a disjunct distribution from European Russia to Central China. The Khamar-Daban Ridge, extending along Lake Baikal’s southern coast, has served as a refugium preserving mesophilic forest remnants in South Siberia since the Pleistocene. This study aimed to elucidate the phylogenetic relationships and historical biogeography of A. altaica within the Khamar-Daban refugium using plastid DNA markers (trnL + trnL-trnF). Phylogenetic and mismatch distribution analysis revealed polyphyly (more specifically diphyly) among A. altaica lineages, suggesting past hybridization events with related species followed by backcrossing. Estimation of isolation by distance effect, spatial autocorrelation analysis, PCoA, and AMOVA indicated a clear spatial genetic structure for A. altaica on the Khamar-Daban Ridge. The most reliable geographical model suggests that during periods of Pleistocene cooling, A. altaica persisted in at least six microrefugia within the ridge. Populations associated with these microrefugia formed western, central, and eastern genetic supergroups with limited gene flow among them. Gene flow likely occurred more easily during glaciations or early interglacials when the subalpine zone shifted closer to Lake Baikal due to the depression of the snow boundary, allowing adjacent populations to intermingle along the glacial edges and terminal moraines in mountain forest belt. Full article

The Eastern Baltic area stands out as a unique location due to the finds of Europe’s youngest dated mammoth remains (12.6–11.2 ka cal BP). Our study explores the drastic climate and landcover changes during the extinction of these gigantic herbivores at the Pleistocene/Holocene boundary. We used macrofossil analysis to determine the major contemporary terrestrial plant genera present in the area and used corresponding pollen taxa for REVEALS model-based landcover reconstructions. Our results indicate that these last mammoths utilised the open landcover of the Eastern Baltic, which developed as the continental ice sheet retreated during the termination of the last glaciation. Due to climate warming during the initial stages of the Holocene interglacial, the Eastern Baltic became speedily populated by birch and pine forests. The abrupt disappearance of typical forb-dominated tundra indicators, such as Dryas octopetala, and the fast increase in tree birch marked a shift from an open, tundra-like landscape to a forested one, making the environment inhospitable for mammoths even in northernmost Estonia by the beginning of the Holocene. A comparison between the isotopic values of nitrogen (δ¹⁵N) and carbon (δ¹³C) obtained from mammoths’ molars from 14.3 and 11.3 to 43.5 and 39.1 ka cal BP showed that mammoths experienced a decline in the nutritional value of their diet, resulting in their demise in the Eastern Baltic. Full article

Precise dating of prehistoric volcanic eruptions is essential for reconstructing eruption sequences and assessing volcanic hazards. The timing of the onset and termination of volcanic activity in the Xilinhot volcanic field (XVF) has been a topic of debate for years. Volcanic eruptions in this area began during the Pliocene, with the K-Ar (Ar-Ar) method providing reliable ages for early formed volcanic rocks; however, this method is less effective for dating younger volcanic events that occurred since the Late Pleistocene. For younger volcanoes, sediments baked by volcanic materials, organic sediments, and silty mudstones entrapped in lava serve as excellent geological carriers for dating. In this study, suitable samples collected from the XVF were dated using ¹⁴C and optically stimulated luminescence (OSL) methods. The ¹⁴C ages obtained for the Gezishan volcano are ~6.8 cal. ka BP, while its OSL age is ~7.8 ka. The ages dated by these two methods, combined with volcano–sedimentary stratigraphic relationships and volcanic topography, confirm the Holocene eruptions of the Gezishan volcano, categorizing it as a broadly active volcano. The upper boundary age of the sandy loam layer beneath the Gezishan lava flow is ~15.5 ka, indicating that the south lava of the Gezishan effusion occurred later than the late stage of the Late Pleistocene. Additionally, the OSL ages of baked sediments at the bottom of the base surge deposits from a Maar-type volcano and aeolian sand interlayers within a Strombolian-type scoria cone in the study area are ~50 ka and ~60 ka, respectively, representing eruptions in the middle Late Pleistocene. These findings demonstrate that volcanic activity in the XVF remained vigorous during the Late Pleistocene to Holocene. This study provides significant insights for reconstructing the evolutionary history of Xilinhot volcanic activity and assessing regional volcanic hazards. Full article

Lithic artifacts are crucial for elucidation of the temporal and spatial patterns of prehistoric human occupation of the Tibetan Plateau. Core-and-flake technology is particularly noteworthy, as it is distinguished by its broad temporal span and widespread distribution across the plateau. In this study, we present the results of a reassessment of the lithic assemblage from the Su-re site in Tingri County, Shigatse City, Xizang Autonomous Region, China. Its resemblance to lithic assemblages from Southwestern China implies a close relationship between the plateau and its southeastern vicinity, contributing to the diversification of technology and prehistoric humans on the Tibetan Plateau. Moreover, gneissic pebbles transported by glacial meltwater in the Tingri Graben—the most suitable raw material available in the vicinity—explains the presence of prehistoric humans in the inhospitable Qomolangma region. Full article

Representatives of the Diodontidae family (porcupinefish) are known to have been fished by prehistoric Indo-Pacific populations; however, the antiquity of the use of this family is thus far unknown. We report here on the presence of Diodontidae in the archaeological sites of Bubog I, II, and Bilat in Mindoro, Philippines, dating back to c. 13,000 BP (Before Present). This evidence demonstrates the early exploitation by islanders of poisonous fish. Every part of porcupinefish can be toxic, but the toxicity is mostly concentrated in some organs, while other parts are edible. The continuous presence of Diodontidae remains throughout the stratigraphic record of these Philippines shell middens suggests that porcupinefish were prepared by human inhabitants of the sites to render them safe for consumption, indicating an advanced cultural knowledge of the preparation needed to separate the toxic principle from the edible parts. This constitutes one of the rare examples of poison processing by humans, aside from the contentious wooden stick poison applicator from Border Cave (South Africa). Full article

Ban Rai Rockshelter in northwest Thailand, dating to the Terminal Pleistocene and Middle Holocene, includes evidence for hunter-gatherer exploitation of mammals, birds, reptiles, fish, and arthropods. Abundant faunal remains, identified throughout site deposits, include macaques (Macaca sp.) and Sambar deer (Rusa unicolor), but these identifications are influenced by an assemblage largely comprised of preserved tooth elements and fragmented bone. Area 3 at Ban Rai has the largest abundance and diversity of faunal remains recovered and identified in this study. Here, we examine the zooarchaeological assemblage from Ban Rai Rockshelter, to understand long-term hunter-gatherer subsistence change, influenced by site preservation, during and after the Pleistocene–Holocene transition. Our results support the presence of the exploitation of arboreal taxa during the Early and Middle Holocene in northwest Thailand. Full article

Carbonate mounds clustering in three fields were characterized on the upper continental slope of the northern Alboran Sea by means of a detailed analysis of the morphosedimentary and structural features using high-resolution bathymetry and parametric profiles. The contemporary and past benthic and demersal species were studied using ROV underwater imagery and some samples. A total of 325 mounds, with heights between 1 and 18 m, and 204 buried mounds were detected between 155 to 401 m water depth. Transparent facies characterize the mounds, which root on at least six erosive surfaces, indicating different growth stages. At present, these mounds are covered with soft sediments and typical bathyal sedimentary habitat-forming species, such as sea-pens, cerianthids and sabellid polychaetes. Nevertheless, remains of colonial scleractinians, rhodoliths and bivalves were detected and their role as potential mound-forming species is discussed. We hypothesized that the formation of these mounds could be related to favorable climatic conditions for cold-water corals, possibly during the late Pleistocene. The occurrence on top of some mounds of abundant rhodoliths suggests that some mounds were in the photic zone during minimum sea level and boreal guest fauna (e.g., Modiolus modiolus), which declined in the western Mediterranean after the Termination 1a of the Last Glacial (Late Pleistocene). Full article

The timing and motivation of prehistoric human expansion into the hinterland of the Tibetan Plateau (TP) is a widely debated scientific issue. Recent archaeological studies have brought forward predictions of the earliest human occupation of the TP to the late–Middle Pleistocene. However, massive human occupation of the TP did not appear until the termination of the Last Glacial Maximum (LGM). The spatio-temporal distribution of prehistoric hunter-gatherers on the TP varies significantly before the permanent occupation after 3600 BP (before present). Here, we report on environmental-archaeological evidence from the Canxionggashuo (CXGS) site in Yushu Prefecture, which provides information that is key to understanding the dynamics of post-LGM human occupation on the TP. Radiocarbon dating has revealed two occupation periods of the CXGS site at 8600–7100 cal (calibrated years) BP and 2400–2100 cal BP. The charcoal concentration in cultural layers correlates well with paleo–human activities. Hunter-gatherers expanded westwards from the northeastern margin of the TP to the hinterland of the TP during the warming period of the early–middle Holocene (~11,500–6000 BP). However, these groups retreated during the middle–late Holocene (~6000–3600 BP) under a cooling-drying climate. Prehistoric humans finally occupied the hinterland of the TP permanently after 3600 BP, with an enhanced cold-adaptive lifestyle, although the climate was still deteriorating. Full article

This study identified the Pleistocene depositional succession of the group (A) (marine, estuarine, and fluvial depositional systems) of the Melor and Inas fields in the central Malay Basin from the seafloor to approximately −507 ms (522 m). During the last few years, hydrocarbon exploration in Malay Basin has moved to focus on stratigraphic traps, specifically those that existed with channel sands. These traps motivate carrying out this research to image and locate these kinds of traps. It can be difficult to determine if closely spaced-out channels and channel belts exist within several seismic sequences in map-view with proper seismic sequence geomorphic elements and stratigraphic surfaces seismic cross lines, or probably reinforce the auto-cyclic aggregational stacking of the avulsing rivers precisely. This analysis overcomes this challenge by combining well-log with three-dimensional (3D) seismic data to resolve the deposition stratigraphic discontinuities’ considerable resolution. Three-dimensional (3D) seismic volume and high-resolution two-dimensional (2D) seismic sections with several wells were utilized. A high-resolution seismic sequence stratigraphy framework of three main seismic sequences (3^rd order), four Parasequences sets (4^th order), and seven Parasequences (5^th order) have been established. The time slice images at consecutive two-way times display single meandering channels ranging in width from 170 to 900 m. Moreover, other geomorphological elements have been perfectly imaged, elements such as interfluves, incised valleys, chute cutoff, point bars, and extinction surfaces, providing proof of rapid growth and transformation of deposits. The high-resolution 2D sections with Cosine of Phase seismic attributes have facilitated identifying the reflection terminations against the stratigraphic amplitude. Several continuous and discontinuous channels, fluvial point bars, and marine sediments through the sequence stratigraphic framework have been addressed. The whole series reveals that almost all fluvial systems lay in the valleys at each depositional sequence’s bottom bars. The degradational stacking patterns are characterized by the fluvial channels with no evidence of fluvial aggradation. Moreover, the aggradation stage is restricted to marine sedimentation incursions. The 3D description of these deposits permits distinguishing seismic facies of the abandoned mud channel and the sand point bar deposits. The continuous meandering channel, which is filled by muddy deposits, may function as horizontal muddy barriers or baffles that might isolate the reservoir body into separate storage containers. The 3^rd, 4^th, and 5^th orders of the seismic sequences were established for the studied succession. The essential geomorphological elements have been imaged utilizing several seismic attributes. Full article

The advances and retreats of ice sheets during Pleistocene significantly changed high- and mid-latitude landscapes and hydrological systems, albeit differently, in North America and Europe. On the southern margin of the Last Glacial Maximum (LGM) in the Baltic Sea basin, a specific type of valley has developed between glacial margins and upland or mountain slopes. We studied new geological data (boreholes, electrical resistivity imaging (ERI) from this geomorphic setting in Northeast Poland to understand: (1) how the landscape and river network evolved to eventually produce peat mires during the Holocene, and (2) the nature of groundwater recharge to fens in the upper Biebrza Valley. We present the results on a geological cross-section with hydrogeological interpretation. We also discuss regional geomorphology. In addition, we present the LGM extent derived from a spatial distribution of Vistulian (Weichselian) terminal moraines. These end moraines are also interpreted as Saalian kames. Thus, we additionally present another method of LGM extent delineation from a physicogeographical division. We link the steep slopes of the studied valley walls (kame terrace fronts) with thermokarst erosion in the periglacial zone. We then document the hydrogeological window (DISCONTINUITY in the till layer over the confined aquifer), which enables the outflow of groundwater into the peat bog. Although minerotrophic fen mire development in the study area is likely to be sustained in the near future through sufficient groundwater supply, the projected capture of the Biebrza River by the Neman River will not allow for sustaining peatland development. Full article

Archaeological research, for several decades, has shown that various microblade technologies using obsidian and hard shale appeared and developed from the Last Glacial Maximum to the terminal Pleistocene (Bølling–Allerød–Younger Dryas) in Hokkaido, Northern Japan. It is well accepted that microblade technology was closely related to the high mobility of foragers to adapt to harsh environments. Recent archaeological and palaeoenvironmental evidence from Hokkaido demonstrates that the disappearance of microblade technology occurred during the terminal Pleistocene, influenced by a wide range of factors, including changes in landscape, climate, subsistence and human populations. The goal of this paper is to provide an overview of the current state of research on the process and background of the disappearance of microblade technology and to discuss prospects for future research. This paper will (1) review palaeoenvironmental research in Hokkaido on changes in climate and biological composition from the terminal Pleistocene to the initial Holocene; (2) survey changes in the technological adaptations and resource use of humans based on the archaeological evidence; and (3) discuss how the abrupt fluctuations of climate that occurred in the terminal Pleistocene affected human behaviour and demographics in Hokkaido. Full article

We made the geochemical analysis of the volcanic material from the sediment core AMK-340 (the Russian research vessel “Akademik Mstislav Keldysh” station 340), the central zone of the Reykjanes Ridge. Two ash-bearing sediment units within the interval of the Termination I can be detected. They correlate with the Ash Zone I in the North Atlantic Late Quaternary sediments having an age of 12,170–12,840 years within the Younger Dryas cold chronozone and 13,600–14,540 years within the Bølling–Allerød warm chronozone. The ash of the Younger Dryas unit is presented mostly by the mafic and persilicic material originated from the Icelandic volcanoes. One sediment sample from this unit contained Vedde Ash material. The ash of the Bølling–Allerød unit is presented mostly by the mafic shards which are related to the basalts of the rift zone on the Reykjanes Ridge, having presumably local origin. Possible detection of Vedde Ash could help to specify the timing of the previously reconstructed paleoceanographic changes for the Termination I in the point of the study: significant warming in the area might have occurred as early as 300 years before the end of the conventional Younger Dryas cold chronozone. Full article

Archaeological excavations at the Cueva del Medio performed during the 1980s and 1990s yielded an important record of both faunal and stone tool remains, as well as data, to discuss issues that occurred during the Terminal Pleistocene. Due to that, the shaped Paleoamerican artifacts collected in the author’s excavations were partially informed. The present article provides unpublished data on the field-work, the results of a techno-morphological analysis of the stone tools, and considerations about early hunter-gatherer societies along with their regional paleo-environmental interactions, as well other topics regarding the regional archaeological process during the last millennium of the Pleistocene. Findings from there have been extremely useful for discussing diverse paleo-ecological and archaeological topics and have extended the knowledge and discussions about different Pleistocene scientific issues, mainly related with flora, fauna, and the colonization of southern Patagonia. Full article

Integrative studies on paleoclimate variations over oceanic and continental regions are scarce. Though it is known that Earth’s climate is strongly affected by sea-air exchanges of heat and moisture, the role of oceans in climate variations over land remains relatively unexplored. With the aim to unveil this influence, the present work studies major climate oscillations in the North Atlantic region and Europe during the Quaternary, focusing on the oceanic mechanisms that were related to them. During this period, the European climate experienced long-term and wide-amplitude glacial-interglacial oscillations. A covariance between the North Atlantic sea surface temperature and climate signals over the continent is especially observed in Southern Europe. The most severe and drastic climate changes occurred in association to deglaciations, as a consequence of major oceanographic reorganizations that affected atmospheric circulation and ocean-atmosphere heat-flow, which led to variation of temperature and precipitation inland. Most deglaciations began when Northern Hemisphere summer insolation was maximal. Increased heating facilitated the rapid ice-sheet collapse and the massive release of fresh water into the Northern Atlantic, which triggered the weakening or even the shutdown of the North Atlantic Deep Water (NADW) formation. Though the extension of ice-sheets determined the high-latitude European climate, the climate was more influenced by rapid variations of ice volume, deep-water formation rate, and oceanic and atmospheric circulation in middle and subtropical latitudes. In consequence, the coldest stadials in the mid-latitude North Atlantic and Europe since the early Pleistocene coincided with Terminations (glacial/interglacial transitions) and lesser ice-sheet depletions. They were related with decreases in the NADW formation rate that occurred at these times and the subsequent advection of subpolar waters along the western European margin. In Southern Europe, steppe communities substituted temperate forests. Once the freshwater perturbation stopped and the overturning circulation resumed, very rapid and wide-amplitude warming episodes occurred (interstadials). On the continent, raised temperature and precipitations allowed the rapid expansion of moisture-requiring vegetation. Full article