Quaternary International最新文献

Aeolian sediments and landforms of the former continental ice sheets' periphery can be used as invaluable sources of information on palaeoenvironmental changes. In the Northeastern Europe, there is very limited knowledge on the structure and age of the aeolian deposits and landforms. This study presents the first data on distribution and chronology of aeolian sediments and landforms in the Vychegda River basin (northeast of the East European Plain). Using grain-size analysis, radiocarbon and OSL dating, we were able to determine the age of the sediments found in the region and study their lithological composition. We discovered aeolian sediments comprising the upper parts of the most river terraces throughout the valley; they come in forms of dunes, dune fields, and sandy or loess-like covers. Previously it was argued that the terraces’ upper parts were comprised by glaciolacustrine deposits, but lithological composition of these sediments showed their aeolian origin. It was found that most of the aeolian sediments have formed in the Late Glacial, between 17 and 10.5 ka. We consider that increased fluvial activity and melting of permafrost were the main causes of the aeolian processes activization and that sediment availability was the most important controlling factor during that time.

The natural environment of the Eemian Interglacial (MIS 5e) and Early Vistulian (MIS 5 d-a) in many areas in Central Europe is still insufficiently and fragmentarily known. Therefore, after the discovery of an almost complete skeleton of the Eemian Stephanorhinus kirchbergensis (Jäger, 1839) in outcrop of palaeolake sediments near Gorzów Wielkopolski (GW site, GS3 profile), a multi-proxy analysis was conducted for a precise recognition of the environmental and climate changes taking place before, during and after the life of this individual. Comprehensive palaeobotanical investigations of sediments of two palaeolakes lying above each other were performed palynological analysis including NPPs and algal analysis, plant macroremains studies (including wood fragments), as well as palaeozoological analyses of the Cladocera, Chironomidae and Coleoptera. The picture of changes in the environment and climate obtained thanks to the performed analyzes presented in a short way looks as follows. The end of the Wartanian Glaciation (MIS 6) was characterised by the dominance of herbaceous vegetation. Along with the gradually changing climatic conditions, the landscape of the Eemian Interglacial was dominated in sequence by birch, pine, oak (the so-called First Thermal Optimum), hazel forests with linden, hornbeam (Second Thermal Optimum) with a rarely recorded dry oscillation, then spruce with fir and again pine forests. The “older Eemian lake” during this time changed from deep, cold, oligotrophic and carbonate to shallower, cold waters with higher trophy, then deeper with lower trophy, again shallower with peats and dystrophic conditions and finally became terrestrial. The age of the post-Eemian part of the GS3 profile was reinterpreted, recognizing OSL dating as more reliable than radiocarbon dating, determining the age as Early Vistulian. Subsequent stages of this part of profile were characterised by significant cooling and intense development of heaths and peatbogs (MIS 5d), double return of pine and birch forests separated by intra-interstadial cooling (MIS 5c), recooling with dominant herbaceous plants (MIS 5b) and last warming with birch forests (MIS 5a). The “younger Early Vistulian lake” was formed with the rising of the water level. It was shallow, cold, low-trophic, with the water heating up in the summer, which caused trophic increases. Water levels fluctuated. With the progressing terrestrialization, oligotrophy appeared. Each of used proxies reconstructs a fragment of palaeoenvironmental changes on land and/or in the reservoir, registering climatic events on both regional and local scales. However, only the combination of all results allows for a full picture of natural changes.

The Xiachuan site (35°26′22″N, 112°00′43″E) in Shanxi Province, northern China is an important Middle and Upper Paleolithic site, which contains four stages of development: the Middle Paleolithic culture, the initial and early Upper Paleolithic culture, the middle Upper Paleolithic culture and the late Upper Paleolithic culture. To establish the chronology framework for the site, a pedo-stratigraphic sequence at the QX2017T1 survey section of Fuyihegeliang Locality (Loc. FYH) was dated using blue-stimulated optically stimulated luminescence (OSL) on fine-grained quartz and post-infrared infrared stimulated luminescence (post-IR IRSL or pIRIR) on fine-grained polymineral. The quartz OSL ages of the Upper Paleolithic culture layer are between 21.4 ± 1.6 and 42.2 ± 3.0 ka, which is consistent with the calibrated ¹⁴C ages. The Middle Paleolithic culture layer is dated to from 118.2 ± 8.5 to 128.3 ± 9.5 ka using the polymineral pIRIR_{100, 290} protocol. These new results allow us to put the main part of the Upper Paleolithic culture layer in the late Marine Isotope Stage (MIS) 3 and the early MIS 2, with the Middle Paleolithic culture layer corresponding to the early MIS 5. A gap of nearly 70 ka is observed between the two cultural layers, which is larger than previously expected. The presence of early hominins in the Xiachuan site during MIS 2 and MIS 3 as well as in early interglacial MIS 5 reflects their ability of adapting to variable environments.

The sedimentary infill of the Quibas karstic site (Early Pleistocene, southern Spain) represents the only continuous succession with remains of continental vertebrates in Europe from pre-Jaramillo to post-Jaramillo age. The Quibas site, with a significant paleontological record, is dated between 1.1 and 0.9 Ma and offers a unique opportunity to carry out a paleoclimatic reconstruction of the time period immediately after the arrival of the first humans to western Europe. For this reason, defining the dominant sedimentary processes in the different stratigraphic units and the associated paleoenvironment is essential. The Quibas site is made up of two karstic features with two stratigraphic sequences: Quibas-Cueva, containing six lithostratigraphic units, and Quibas-Sima, which contains seven lithostratigraphic units. The detailed description and analyses of the stratigraphic sections have allowed the characterization of various autochthonous and allochthonous facies of cave deposits. Paleoclimatic proxies, inferred from sedimentological analyses, reveal a record of several alternating humid and arid phases resulting from the Early Pleistocene glacial-interglacial cycles, allowing correlation to the marine oxygen isotope record. The lowermost units (pre-Jaramillo) were deposited during a long-lasting interglacial, correlated to MIS 33–31. It was followed by an increase in aridity in the intermediate units of Quibas-Sima and uppermost unit of Quibas-Cueva (Jaramillo), revealing the beginning of a glacial period at the start of the Jaramillo subchron (1 Ma), which can be correlated to MIS 30. The upper Jaramillo and post-Jaramillo units suggest these were deposited in alternating periods of aridity and humid conditions, although less humid than the pre-Jaramillo period, probably representing the MIS 29 interglacial, the MIS 28 glacial and the MIS 27 interglacial.

Potash, also known as potassium (K), is a crucial component of the agricultural sector and serve as “the food of food”. Historically, the formation of potash deposits has been attributed to the “tectonic-climatic” theory, in which the role of prolonged arid climate is still debating. Consider the minerogenetic time scale, paleoclimatic events may have played an undeniable role in the formation of potash. However, few studies have been conducted on this topic, which may impede theoretical development. The Lop Nur playa of the Tarim Basin, Northwest China, is a typical hinterland salt lake that formed during the combined effect of the collision between the Eurasian Plate and the Indian Plate and the Quaternary climatic background. As a potash metallogenetic area, Lop Nur is the best place to study how paleoclimatic events affect salt mineralization. In this study, we summarize the development of paleoclimate records and multiple ages from Quaternary sediments and analyze the mineralization theory of the Lop Nur salt lake. The comprehensive chronicle framework employed in paleoenvironmental reconstruction has unveiled the fluctuating aridity and the subsequent process of playa formation. By integrating mineralization mechanisms, ranging from the “mountain-basin transfer” theory to the “tectonic-climatic-source coupled” theory, we systematically reviewed the potential impacts of paleoclimatic events as both impetuses and limitations in the formation of potash deposits in Lop Nur. From a more prospective aspect of this review, the paleoclimatic events for potash mineralization are examined in relation to the worldwide distribution of salt lakes. This examination takes into account the lacustrine paleo-proxies and potash types, which indicate similar paleoclimatic influences on the mineralization process, albeit with varying origins. In the future, a more comprehensive understanding of potassium salt resources can be achieved through a thorough comparison of reconstructed paleoenvironments and high-resolution regional mineralization modeling results.

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

The integration of high-resolution seismic profiles, core data and radiocarbon plus U-Th datings, allows to document the late Quaternary succession of the Trieste Gulf, which represents the easternmost part of the northern Adriatic Sea. This succession consists of an alternation of shallow-marine and continental deposits organized to compose four transgressive-regressive sequences down to ca. 90 m below present sea level. The sequences terminate landwards against a stepped surface bounding the Eocene Trieste Flysch and produced by alternating episodes of wave erosion during transgressions and subaerial exposure during stages of relative sea-level fall and lowstand. Two shallow-marine wedges, in addition to the Holocene one, have been recognized; they are associated with the Marine Isotopic Stage (MIS) 5.5 (Tyrrhenian) and probably at least one of the peaks of MIS 7. The recognized shallow-marine wedges typically prograde just seaward of a buried wave-cut platform lying in front of a receding paleo-coastal cliff. A previously unrecognized stratigraphic hiatus of ca. 25 ka duration, containing the whole Last Glacial Maximum (LGM) phase, was found at the top of palustrine deposits that accumulated on the MIS 5.5 marine sediments until ca. 40 cal ka B.P. and a post-LGM peat bed accumulated during the Younger Dryas stadial. The beginning of the Holocene was characterized by marked fluvial aggradation preceding the marine transgression at ca. 11-10 cal ka B.P. This new evidence is invaluable for better understanding late Quaternary sedimentary and erosional episodes that characterized the easternmost part of the norther Adriatic Sea, in the frame of the well-known glacio-eustatic sea-level changes.

Plio-Pleistocene sedimentary successions, comprised of fluvio-glacial-lacustrine sediments capped by loess, are widespread in the Kashmir Valley, NW Himalaya, India. These sediments act as a repository of climate records for the past 4.4 Ma suggesting the dominance of southwestern monsoon up to 1.95 Ma and thereafter the dominance of mid-latitude western disturbances in the region. However, the younger strata of the loess-paleosol sequences (LPSs), <200 ka old, and Holocene sediments have been studied for high-resolution climate records compared to older archives because of the contentious chronological issues of the older deposits. Earlier studies revealed moderate climatic conditions from ∼65.8 ± 7.2 ka to 44.3 ± 5.8 ka, followed by periods of extreme dry phases of enhanced wind velocity, coinciding with the last major magnetic inversion. The climatic conditions have produced strong pedogenic signatures on the LPSs during the MIS-3 (∼43–34.7 ± 2.3). The dry arid climate phases recorded during the MIS-2 stage up to ∼14.7 ± 5.4 ka revealed a weak pedogenic alteration and a high amount of CaCO₃ accumulation in the loess. Subsequent sporadic alluvial deposition of sediments over the LPSs implies widespread precipitation and glacial melting linked to the onset of the Holocene warming punctuated by dry and cold climate phases corresponding to the Bond events of 0, 3, 4, 5, and 7, which indicated a westerly-dominated climate during the Holocene. This review therefore critically examines existing literature on Karewa deposits in the Kashmir Valley, identifies knowledge gaps, and offers recommendations for future research, emphasizing their paleoclimatic potential for the Quaternary Period.

This is a critical review of disputable chronostratigraphic results in the Upper Pleistocene of glaciated Russia including the West Siberian and Russian Plains. The main goal is to assess the validity of stratigraphic tools used for long-distance correlation of young sedimentary formations. The test is performed by comparison of i) Russian stratigraphic schemes of two last glacial cycles against the West European ones and ii) the traditional stratigraphic scales of Russia against the new chronological results brought up by modern dating tools. The multitude of AMS radiocarbon, optical luminescence, uranium series and electron-spin resonance dates obtained by international research projects allowed to reconsider the age of the main stratigraphic markers of Siberia which proved to be by one glacial cycle older than suggested by the traditional correlation schemes. The correlation wisdom in central European Russia for the time being cannot be satisfactorily revised using the statistical approach because of the limited supply of chronometric data. The palaeoenvironments inferred from palynological data in central European Russia are in discrepancy with the presumably coeval periglacial landscapes of Western and Central Europe. This divergence implies that the traditional chronostratigraphic correlation of the older Middle Valdaian interstadials with their Pleniglacial counterparts of MIS 3 stage is probably erroneous. The correlation errors mainly stem from the age underestimation by conventional radiocarbon dates used as chronological links of the Russian Pleistocene formations.

To understand the role of the East Asian summer monsoon (EASM) and the East Asian winter monsoon (EAWM) on the hydroclimate in northern Taiwan, a multiproxy study has been conducted. This study aims to achieve its goal by using micro-XRF data of Ti and sulfur (S), carbon isotopic compositions (δ¹³C) along with elemental concentrations of carbon (C), nitrogen (N) and S, and diatom analyses in the sediment core extracted from the Dream Lake (DL; 25°10′01.9″ N, 121°33′36.0″ E and elevation = 588 m above sea level), northern Taiwan. The radiocarbon dates revealed that the DL core covered the time interval from 4.5 to 0.4 cal kyr BP. The current records revealed wetter phases during 4.5–3.0 cal kyr BP, 2.0–1.7 cal kyr BP, and 1.0–0.4 cal kyr BP, characterized by the dominance of C3 plants in the DL catchment, increased runoff, and higher lake levels. Drier climates observed in the current study during 3.0–2.0 cal kyr BP and 1.7–1.0 cal kyr BP, marked by a reduction in C3 plants, decreased runoff, and lower lake levels. The northern Taiwan climate during the late Holocene was observed to be regulated by the interplay of EASM and EAWM. The wet climate conditions during 4.5–3.0 were due to the La Niña-like conditions, which led to a strong EASM resulting in high precipitation conditions. The dry climate conditions during 3.0–2.0 cal kyr BP have coincided with El Niño-like conditions during 3.0–2.4 cal kyr BP and a subsequently strong EAWM during 2.4–2.0 cal kyr BP. Both situations led to a reduction in precipitation in the region. Unlike the time frame from 4.5 to 3.0 cal kyr BP, wet climate conditions during 2.0–1.7 and 1.0–0.4 cal kyr BP have coincided with weak EAWM conditions, which led to an increase in precipitation in northern Taiwan. The dry climate noticed between 1.7 and 1.0 cal kyr BP appeared to be the impact of both El Niño-like conditions and strong EAWM.