Ka BP Research Articles

Technical-Typologic Characteristic of Microcores of the Cultural Horizon 3B of the Kovrizhka IV Site (Vitim River, Baikal-Pathom Uplands) with Application of Morphometry Based on 3D Modelling

Purpose. The study consists of results of a technical-typologic analysis of microcores and ski-spalls from 3B cultural horizon of the Kovrizhka IV site (Lower Vitim and Baikal-Pathom Uplands) with morphometric characteristics obtained by means of 3D modelling. This assemblage is dated to about 18.8 cal ka BP and refers to the early phase of the LUP. Production of microblades is represented by 5 microcores, 2 preforms, 3 ski-spalls, 174 whole and fragmented microblades. The aim of the study is to characterize the microblade splitting technology by new data of the variability of the microcore preparation.Results. The preforms for microcores were both bifaces and spalls. Ski-spalls indicate the presence of the technique of Yubetsu. For the first time in the region’s archeology the most diverse ways of manufacturing microcore, including the variants of transverse, parallel, and diagonal design of the striking platform relative to the longitudinal axis of the spall-preform have been revealed in one episode of habitat. It was established that the volume of microcores from biface in the initial stage is higher than the volume of micronucleus from the spall by 2-3 times.Conclusion. The variety of forms and ways of obtaining microcore is valued as a sure mastery of ancient masters of the technology of the microblade production. The Kovrizhka microcore technique is widely represented in subsequent assemblages of the Lower Vitim up to the early Holocene, similar final forms are also typical in the general context.

The Peopling of Uzbekistan by Homo sapiens Denisovan

The Peopling of Uzbekistan by Homo sapiens Denisovan

Preservation of Organic Matter Within Primary Fluid Inclusions in Late Middle Pleistocene Halite From the Mars‐Analog Qaidam Basin

AbstractHalite minerals, widespread across Mars, have captured significant attention from geologists and astrobiologists for their potential to preserve biosignatures. Here, we report the preservation of organic matter within primary fluid inclusions in a halite duricrust, dated to 197.8 ± 36.2 ∼ 226.0 ± 29.0 ka BP, obtained from the Mars‐analog Qaidam Basin, NW China. Employing transmitted and fluorescent light microscopy alongside Raman spectroscopy, we identified abundant β‐carotene, lipids, and kerogen within these fluid inclusions. Notably, lipids were detected in situ and non‐destructively within fluid inclusions in salts. The presence of genes associated with microbial synthesis of carotenoids, such as β‐carotene, across diverse prokaryotes suggests that these microorganisms could be a potential source of β‐carotene preserved in halite salts. The consistent spatial co‐occurrence of β‐carotene and anhydrite within all identified anhydrite‐containing inclusions in this study implies potential interactions between carotenoid‐producing microorganisms and sulfate minerals. This study underscores the significance of the preservation of biosignatures in near‐surface salts in the search for life on Mars.

New coastal records in northern Brittany (Plouescat, NW France): Sedimentological, palynological and paleogenomic data over the last 7.3 ka BP.

New coastal records in northern Brittany (Plouescat, NW France): Sedimentological, palynological and paleogenomic data over the last 7.3 ka BP.

A Late Quaternary Foraminiferal Record of Deep-Water Ventilation Changes below OMZ in the Northwest Arabian Sea

ABSTRACT This study is primarily based on the census data of late Quaternary foraminifera from Ocean Drilling Programme (ODP) hole 722B, which is situated beneath the Oxygen Minimum Zone (OMZ) at 2028 m of water depth in the northwest Arabian Sea near Owen Ridge. The purpose of this investigation is to improve our understanding of the history of deep-water ventilation in the northwest Arabian Sea under the combined influence of surface productivity produced by monsoonal upwelling and the northward outflow of deep water originating in the south. The prominent occurrence of Bulimina alazanensis-Globocassidulina subglobosa assemblage along with low organic matter influx at the seafloor during interglacial MIS 5 (including 5.5 and 5.1) and Holocene indicate better ventilated bottom water due to enhanced northward incursion of oxygen-rich North Atlantic Deep Water (NADW) up to the northwest Arabian Sea. On the other hand, enhanced upwelling caused by an intense southwest monsoon yields more productive surface water, as demonstrated by higher relative abundance of Globigerinita glutinata . Thus, despite the strong SW monsoon circulation and increased surface productivity, the higher organic matter remineralization under better deep-sea ventilation reduced the amount of available organic matter on the sea floor. The prevalence of Bulimina aculeata assemblage, increased abundance of dysoxic taxa and higher percentage of organic matter during latter part of Last Glacial Period (~55 to 15 ka BP) indicate decline in the deepwater ventilation and better trophic condition at the bottom possibly due to reduced incursion of NADW into the northwest Arabian Sea. In the deep-sea during glacial MIS 4 and cold stadial MIS 5.2, the prevalence of Bulimina aculeata and Uvigerina proboscidea assemblages along with higher abundance of shallow infaunal taxa shows a minor decline in the dissolved oxygen or nearly unchanged deep-water ventilation with moderately higher trophic levels.

Late Pleistocene–Holocene environmental fluctuations of southern Chihuahua Desert, Mexico

ABSTRACTPaleoenvironmental reconstructions from the Mexican Chihuahua Desert based on biological proxies are scarce, creating a gap in our understanding of the ecological responses to climate change in this water‐scarce region. Here, we present a paleoenvironmental reconstruction based on geochemical data and biological proxies such as ostracods and ephippia from cladocerans from the Santa Clara basin, at the southern Chihuahua Desert, during the last 18.7 cal ka. Overall, cold and humid conditions between 18.7 and 15 cal ka BP prevailed in the Santa Clara region without ostracod preservation. During the warmer Bølling‐Allerød, L. axalapasco presented higher productivity; however, this species did not occur during the colder Younger Dryas. The early Holocene was marked by a general trend towards warmer and dryer conditions, and a sedimentary hiatus was detected from 10.7 to 6.4 cal ka BP. Subsequently, when the North American Monsoon reached its maximum extension, ostracods exhibit their maximum total abundance during 6–4.8 cal ka BP, indicating warmer and shallower lake conditions. The presence of only females of L. bradburyi between 4–2 cal ka BP possibly suggests lower lake water temperatures associated with enhanced winter precipitation under El Niño type conditions. Finally, during the last 2 cal ka ephippia, L. axalapasco females and geochemical data suggest the driest period of the record as the ITCZ continued moving southwards. This work reveals the marked sensitivity of southern Chihuahua Desert ecosystems to the climatic shifts that occurred since the Last Glacial Maximum, and this perhaps indicates their vulnerability to future global warming reducing monsoonal precipitation.

Archaeomagnetic Tools Applied to the Study of Middle Palaeolithic Hearths: The Level R (ca. 60 ka BP) at Abric Romaní (NE Iberian Peninsula)

Due to its long occupation throughout the Middle Palaeolithic and the abundance of its pyrotechnological evidence, the Abric Romaní rockshelter (Capellades, Barcelona) provides an ideal setting for studying Neanderthal fire use. We conducted an archaeomagnetic study of four hearths from Level R (ca. 60 ky BP). Rock magnetism experiments, including hysteresis loops, and backfield, isothermal remanent magnetisation acquisition and thermo-magnetic curves, were conducted on three specimens per hearth to investigate their magnetic mineralogy. To explore the raw material’s ability to become magnetised, we performed a laboratory-induced partial thermo-remanent magnetisation acquisition in a 50μT field at various increasing temperatures. Our results indicate that the material is predominantly diamagnetic, but contains a small proportion of low coercivity magnetic minerals, likely magnetite. A total of 106 oriented specimens underwent progressive thermal demagnetisation up to 580 °C. Directional results at the specimen level show either a single component or two: one between 250 and 420 °C and another between 300 and 550 °C. Three out of the four hearths yielded normal-polarity archaeomagnetic directions, within the range of secular variation expected for their estimated age; the poor quality of the data prevented any analysis of the remaining structure. These findings suggest that, despite the hearths’ low content in ferromagnetic minerals, they are able to acquire a thermal or thermochemical-remanent magnetisation, accurately recording the Earth’s magnetic field though their high-temperature component. The low-temperature component may reflect a subsequent thermo-chemical or chemical alteration that partially remagnetised the original direction.

Rainfall-triggered landslides from the January 2023 1-in-200 year storm at Maungakiekie/One Tree Hill, Auckland, New Zealand

ABSTRACT We describe engineering geological characteristics and failure mechanisms of shallow soil landslides activated on Maungakiekie/One Tree Hill in central Auckland, New Zealand on 27 January 2023. The hill is a scoria cone in the young Auckland Volcanic Field (AVF), and formed ∼60 ka BP. Subsequently, much of the volcano was blanked by 3–5 m of fine volcanic ash, erupted from neighbouring Three Kings volcano ∼28.5 ka BP, on which residual soils have formed. These slopes were then terraced using cut-and-fill earthworks by pre-European Māori until abandoned in 1822. The terraces remained largely intact until 27 January 2023 when the ‘Auckland Anniversary Storm’ (a > 1-in-200-year event), crossed Auckland, triggering 19 shallow failures on the terraced slopes. Accordingly, we investigated the geotechnical characteristics of the volcanic soils associated with these landslides. An important destabilising factor is the presence of thin (∼20 mm) layers of weathered Three Kings ash exposed within the 1–2 m high headscarps. These dip unfavourably out of the slope, also acting as an aquiclude, leading to increased porewater pressure in overlying soils. The occurrence of landslides only on ‘filled' slopes supports emerging evidence that human disturbance may be a more important future landslide conditioning factor than climate.

Two types of modern sediment dispersal systems in the western Taiwan foreland basin: Sediment transfer from basin to basin

AbstractThe western Taiwan foreland basin (WTFB) is a classical peripheral foreland basin longitudinally bounded by the East China Sea (ECS) to the north and the South China Sea (SCS) to the south. Sediments spill longitudinally into the nearby marginal ocean basins, similar to the typical foreland basin setting. Due to oblique collision in the Taiwan region, the WTFB has evolved into two subbasins: a mature basin dominated by fluvial sediments in central‐northern Taiwan and an immature one dominated by deep marine facies offshore south‐western Taiwan, accompanied by two distinct sediment routing systems. In the north, the Choushui River drainage, narrow seaway of the Taiwan Strait, Huapingshu Channel/Mienhua Canyon System and southern Okinawa Trough (SOT) are integrated into a united sediment dispersal system, allowing sediments sourced by the mature basin to laterally overflow into the ECS and be deposited into the SOT. In southern Taiwan, the Kaoping River drainage, Kaoping submarine canyon, Penghu submarine canyon, deep‐sea Penghu Channel and SCS basin interconnect, forming a longitudinal dispersal system for sediments mainly derived from the southern Taiwan orogen to be longitudinally transported to the northern SCS basin and the northernmost Manila Trench. The oblique collision between the Luzon Arc and the Chinese margin in the Taiwan region is the major factor in the development of two distinct sediment dispersal systems. Preferential sediment transport (axial vs. transverse), shelf width and sea‐level change since the Last Glacial Maximum (~2 ka BP) are the other significant factors in the development of sediment routing systems in the WTFB. The two proposed distinct sediment dispersal systems in the WTFB clearly demonstrate how foreland basin sediments can be transferred longitudinally to adjacent marginal sea basins. Moreover, the sediment dispersal systems in the WTFB can be considered a modern analogue for interpreting ancient counterparts.

Fire Use During the Last Glacial Maximum: Evidence From the Epigravettian at Korman' 9, Middle Dniester Valley, Ukraine

ABSTRACTThe Last Glacial maximum (LGM), spanning from 26.5 to 19 thousand years before present (ka bp), is a period of extreme climatic degradation associated with reduced biomass production and resource stress throughout Eurasia. Arguably, one of the most fundamental tools for human survival during this cold and arid period was the ability to create, maintain and use fire. While fire is widely considered a ubiquitous tool in modern human behaviour, there are surprisingly few well‐described combustion features during the LGM in Europe. In this paper, we provide high‐resolution geoarchaeological research into three combustion features associated with Epigravettian occupations at the site of Korman' 9 (Ukraine) with ages falling in the LGM. Our results show distinct variations in the size and structure of the combustion features, potentially indicating multiple occupations within the same layer or reflect differences in site organization or function during a single occupation. Additionally, our analysis shows clear evidence of the effect of solifluction and the lack of preservation of the ash layer(s) of the combustion features, as well as the development of bioturbation features enhanced by anthropogenic input. To better estimate heating temperatures of the combustion events, we employed a novel approach using colour analysis showing temperatures reaching 600°C in the substrate underlying the combustion features. In all, the combustion features at Korman' 9 provide invaluable new insights as well as high resolution description of pyrotechnological behaviours during the LGM, which has been lacking during this critical period in our evolutionary history.

Caspian — Black Sea Connection During MIS 5 (Late Pleistocene): Evidences from Drilling Data

Abstract The Caspian and Black Seas are adjacent inland bodies of water, each with its unique palaeogeographic history. The Black Sea has been connected to the World Ocean throughout its Quaternary history. In contrast, the Caspian Sea has been completely isolated since the beginning of the Middle Pleistocene. Since then, the Caspian Sea has occasionally discharged its excess waters through the Manych Depression into the Azov-Black Sea Basin. As a result of this isolation, unique species have developed in the Caspian Sea. The transgressive-regressive cycles of the Caspian Sea are associated with global and regional climate fluctuations since its sea level depends on its water balance. Due to the penetration of Caspian species into the Manych Depression and further into the Azov-Black Sea Basin, it is possible to determine episodes of its transgressive water discharge, assess the characteristics of the existing basins, and correlate these episodes not only with events within the Mediterranean—Black Sea—Caspian corridor but also with global events. The study of the connection between the Black and Caspian Sea basins dates back to the 18th century. Thereafter, numerous publications have addressed various aspects of the palaeogeography of the region. However, the events within these two basins during Marine Isotope Stage 5 (MIS 5) and their scales and characteristics remain debated. This research focused on studying the MIS 5 Epoch, which includes the Holocene-analogous Eemian interglacial period and the transition to the Early Weichselian glacial Epoch. To reconstruct the events in the Black Sea—Manych Depression—Caspian Sea during MIS 5, we conducted lithological, malacofaunistic, and geochronological analysis on six borehole sections in the Northern Caspian, four in the Manych Depression, and three in the northeastern sector of the Black Sea to identify events that occurred in basins, assess their environmental characteristics, conditions of sedimentation and time frames. We have discovered that the Karangatian transgression (analogous to the Eemian transgression in the Mediterranean Sea) ingressed into the Manych Depression 125–110 ka BP (MIS 5e–d) during its maximum phase and formed a gulf there with a water salinity of up to 18‰, featuring Mediterranean mollusc fauna. Later, the waters of the Hyrcanian transgression of the Caspian Sea exceeded the water divide of the Azov-Black Sea and Caspian Sea basins and began to spill over into the Manych Depression. This influx of water resulted in the desalination of the sea gulf that was present there, reducing its salinity to values of less than 14‰. This event occurred around 110–105 ka BP (MIS 5c). The Karangatian waters eventually left the Manych Depression, but Hyrcanian waters continued to flow into the Black Sea until ~ 100 ka BP. This is evidenced by characteristic Hyrcanian species, such as Didacna cristata and D. subcatillus, found in the upper part of Karangatian sediments in the Manych Depression and on the northeastern shelf of the Black Sea. The Hyrcanian water discharge marked the initial flow of Caspian water into the Black Sea during the late Pleistocene, occurring unilaterally without any exchange between these two basins. Reconstructing the transition from the interglacial to the glacial period during MIS 5 can provide valuable insights into the expected changes in the Black Sea—Manych Depression—Caspian Sea system as we move from the current Holocene interglacial into a new glacial period.

Prehistoric human hand and footprints in Quesang on the central Tibetan Plateau from the Bølling-Allerød Interstadial

Multidisciplinary research has examined prehistoric human adaptation and survival in the Tibetan Plateau’s alpine and hypoxic environment. As an important prehistoric human hand and footprint site for studying prehistoric human activities, Quesang, on the central Tibetan Plateau, has witnessed prehistoric human arrivals at least twice: in the Middle Pleistocene and early-middle Holocene. Recent investigations along the gully incised by water flow of the active spring have discovered a series of prehistoric human footprints and repeated trampling marks on the residual travertine in the different locations of gully and their ichnological characteristics and ages are unknown. To determine whether and when the imprints were left by Hominin and explore their association with the surrounding environment and landform evolution, we conducted detailed stratigraphic and geomorphological analysis of travertine deposit, 3D modelling and morphological study of hand and footprints, as well as Uranium–Thorium and optically stimulated luminescence dating of hand and footprints and strata. Based on these analyses, we obtained the following results: The active hot springs formed after 17.37 ka BP, probably when the Bølling-Allerød Interstadial began. The newly discovered footprints and repeated trampling traces are ichnologically identified as Hominin traces, which were unintentionally impressed at ~ 8.5–9.2 ka BP and ~ 14.2 ka BP, respectively, and are related to the development of the gully. In the cold, dry, and anoxic environment of the Tibetan Plateau, the Quesang hot spring is undoubtedly a very attractive survival resource, attracting prehistoric humans to frequently patronise it for a long time. The discovery of these imprints provides new evidence of prehistoric human expansion and occupation on the Tibetan Plateau before and in the Holocene.

Метод компьютерной микротомографии для изучения составных пазовых орудий

Recent advances in the use of computed microtomography (micro-CT) in archaeology have significantly improved the potential for the accurate non-destructive study of artifacts, making it possible to analyze their internal structure. The paper demonstrates the micro-CT method potential for the study of archaeological artifacts. Four composite slotted tools from the Kazachka site (Krasnoyarsk Krai), dated to between 11 and 8,5 ka BP, were selected to illustrate the method’s capabilities. The site, situated in the valley of the Kan River, contains a sequence of 20 layers ranging from the Final Paleolithic through the Early Iron Age. The study involved the analysis by micro-CT of two bone hafts with preserved inserts from layers XIV and XII, and two bone hafts devoid of inserts from layers XIX and XI. The employment of micro-CT facilitated the visualisation of artifacts and the analysis of slots geometry, thereby facilitating insights into their manufacturing sequences and characteristics. The segmentation process (i.e., the virtual separation of constituent parts of different densities) allowed for the extraction and detailed analysis of the inserts from the bone handles. The discrepancy between the slot depth and the insert width suggests the use of adhesives to secure the inserts and fill the voids — a hallmark of Late Paleolithic-Mesolithic composite technologies. This study highlights the significant potential of micro-CT in examining composite artifacts without the risk of damage, offering a novel approach to analyzing complex multi-component tools.

South American Great Basin: Limnogeological analysis of the Salina del Bebedero Basin, Argentina (Late Pleistocene‐recent)

AbstractThe Bebedero tectonic depression in San Luis province, Argentina, is a closed drainage basin that has formed as a result of block‐faulting and rifting processes. The Bebedero lake exhibits notable similarities to the endorheic watersheds of the western United States, particularly those of Death Valley, the Saline Valley and, to a lesser extent, the Great Salt Lake. While it is currently classified as a playa lake, there is evidence of lake levels near the sill that overflowed during the Late Pleistocene. Several lines of evidence suggest that climate is the major controlling factor in the basin's fill. The Salina del Bebedero Basin is an underfilled lake basin type, particularly a discharge lake basin. This assertion is supported by recent findings, including precise topography, stratigraphy, facies associations, radiocarbon ages and palaeontology from one section and two transects. The following presentation comprises stratigraphic correlations, palaeoenvironmental reconstructions and a graphical model of lake stages based on these new results and previously published research. This paper provides a model of lake‐level fill from the Late Pleistocene to the present, identifying distinct highstands and lowstands associated with global climate events. The surface and depth of the lake were reconstructed for each stage. The maximum expansion was estimated at 1000 km2 during the Pre‐Last Glacial Maximum and 782.6 km2 during the Last Glacial Maximum, with depths ranging from 60 to 75 m. Lake Bebedero exhibited similar lake‐level responses to climate variations as Lake Bonneville, Great Salt Lake, as well as sub‐environmental similarities with Death Valley and the Saline Valley. In addition to its palaeoclimate significance, Lake Bebedero has archaeological records of an early settlement dating back ca 10 to 6 cal ka BP. The scarcity of data concerning the early human settlement in southern South America makes archaeological evidence relevant. Therefore, the inferences regarding climate and environment derived from studies of the lake provide important information about the first human groups to populate these regions.

Late Holocene Indian summer monsoon evolution and centennial fluctuations inferred by grain-size sensitive component from Lake MangCo, southeastern Tibetan Plateau

Identifying the late Holocene Indian summer monsoon (ISM) changes and their possible forcing mechanisms provides an important perspective for understanding the current monsoon shifts driven by anthropogenic climate change within a natural baseline. In this study, we present a well-dated, ca. 4.0 ka grain-size sensitive component record from Lake MangCo, located in the southeastern Tibetan Plateau. The record depicts late Holocene ISM evolution and centennial-scale precipitation events superimposed on millennial-scale climate changes. The results indicate that precipitation was relatively high during the first half of the late Holocene, likely before 2.0 cal ka BP, followed by a period of relatively reduced precipitation thereafter, which indicates that the Northern Hemisphere summer insolation (NHSI) has primarily controlled ISM intensity. A slight increasing trend in ISM strength since 1.1 cal ka BP was observed, which may correspond to the reported “2.0-kyr-shift” and could be related to warming tropical temperatures. Three low precipitation intervals, occurring at ∼1.1, 2.0, and 3.2 cal ka BP, align well with known centennial-scale ISM weakening events during the late Holocene, such as the Medieval Warm Period (MWP) and the “2.0-ka-dry-event.” Our findings further validate the climatic effects of tropical ocean–atmospheric interactions in the Pacific and Indian Ocean basins on ISM variabilities at centennial timescales.

High-Resolution Reconstruction of Total Organic Carbon Content in Lake Sediments Using Hyperspectral Imaging

The total organic carbon (TOC) content in lake sediments is an effective archive indicating past climate changes. However, the resolution of the TOC record has generally been limited by factors such as subsampling intervals, hampering further comprehension of past climate change. Recently, hyperspectral imaging technology has been increasingly employed to scan lake sediment cores, presenting new opportunities to reconstruct high-resolution sequences, but the reconstruction of long-term high-resolution TOC records using hyperspectral imaging and the climate implications have not been well studied. In this study, we scanned sedimentary cores from Wudalianchi Crater Lake in northeast China with a spatial resolution of 400 × 400 μm, utilizing visible and near-infrared (VNIR) hyperspectral imaging technology. Then, a partial least-squares regression (PLSR) model was constructed by comparing eight different preprocessing methods and optimally selecting the best spectral subset combined with a genetic algorithm (GA). Our analysis demonstrates that the PLSR model, constructed using 62 relevant bands selected by the Savitzky–Golay second derivative (D2) preprocessing method and GA, was the most reliable, with the validation set’s R-value reaching a high of 0.91 and RMSE as low as 1.18%. Notably, the spectral range of 656–669 nm showed a strong positive correlation with measured TOC, indicating its sensitivity for TOC estimation. Given this advantage, we reconstructed the TOC records of sediments from the Wudalianchi Crater Lake during the 38–13 ka BP period, which exhibited significant millennial-scale fluctuation events. These corresponded well with the millennial-scale events in pollen and TOC from Lake Sihailongwan, δ18O records of Greenland ice cores, and δ18O records from Asian stalagmites. Thus, the combination of hyperspectral imaging and the PLSR model is effective in reconstructing high-resolution TOC changes in lake sediments, which is essential for understanding climate change as well as carbon burial in lakes.

Sea level since the Last Glacial Maximum from the Atlantic coast of Africa

Constraining sea level at the Last Glacial Maximum (LGM) is spatially restricted to a few locations. Here, we reconstruct relative sea-level (RSL) changes along the Atlantic coast of Africa for the last ~30 ka BP using 347 quality-controlled sea-level datapoints. Data from the continental shelves of Guinea Conakry and Cameroon indicate a progressive lowering of RSL during the LGM from −99.4 ± 5.2 m to −104.0 ± 3.2 m between ~26.7 ka and ~19.1 ka BP. From ~15 ka to ~7.5 ka BP, RSL shows phases of major accelerations up to ~25 mm a−1 and a significant RSL deceleration by ~8 ka BP. In the mid to late Holocene, data indicate the emergence of a sea-level highstand, which varied in magnitude (0.8 ± 0.8 m to 4.0 ± 2.4 m above present mean sea level) and timing (5.0 ± 1.0 to 1.7 ± 1.0 ka BP). We further identified misfits between glacial isostatic adjustment models and the highstand, suggesting the interplay of different ice-sheet meltwater contributions and hydro-isostatic processes along the wide region of Atlantic Africa are not fully resolved.

Reconstruction of the paleoenvironmental context of Holocene human behavior at the Fenghuangzui site in the Nanyang Basin, Middle Yangtze River, China

Geomorphological research at archaeological sites reveals that environmental factors, such as geomorphology and hydrology, play a crucial role in understanding changes in site layout and cultural processes. However, due to the lack of reliable chronologies, there is limited understanding of environmental factors in relation to archaeological site. This study focuses on the sedimentary records from the southern moat of the Fenghuangzui (FHZ) site, a representative site in the middle Yangtze River region, integrating a chronological framework and climate proxies such as elemental geochemistry. It reconstructs the evolution of the regional sedimentary environment and the hydrogeomorphology during the mid-late Holocene at the FHZ site, elucidating its interplay with human activities. Key findings include: (1) From 5.6–4.5 ka BP, elevated chemical index of alteration (CIA), Rb/Sr, and Mn/Ti values indicate a warm and humid climate. The Qujialing culture unified the middle Yangtze River and established regional central settlements such as Shijiahe site, and then expanded to the north. The FHZ site was built in the Nanyang Basin at this time to prevent the invasion of northern culture. (2) During 4.5–4 ka BP, decreased CIA and Rb/Sr values alongside rising secondary aluminum factor (Saf) and dealkalization coefficient (Bc) values signify reduced weathering and a transition to cooler, drier conditions. A flood event of 4–3.9 ka BP caused the moat of the FHZ site to lose its defensive function. (3) During 4–2.7 ka BP, declining CIA and Rb/Sr values with slight increases in Saf and Bc suggest ongoing dry and cool environmental conditions. The FHZ site was abandoned at the end of the Meishan culture. (4) Between 2.7–1.6 ka BP, rising CIA and Rb/Sr values indicate a return to warmer and more humid conditions. The FHZ site was built to expand the influence of Qujialing culture and protect the Shijiahe settlement. Taking into account the location of the water system and farming area, the south-facing direction was chosen. In general, our findings suggest that changes in regional hydrology in the context of climate change can trigger upheaval and even collapse of prehistoric societies.

Vegetation, Architecture, and Human Activities: Reconstructing Land Use History from the Late Yangshao Period in Zhengzhou Region, Central China

In recent decades, a large number of houses from the Late Yangshao period have been excavated in Zhengzhou. They are basically single-level buildings with wood skeletons and mud walls and use a huge amount of timber resources. Nevertheless, there are still a lot of questions about the uncertain relationship between plants, architecture, and human activities. In this study, we complete the reconstruction of a Holocene vegetation community around the Dahecun site via pollen analysis of the Z2 core. We take house F1 in Dahecun as an example to estimate the wood consumption of a single house and collect the published data of all houses from the Late Yangshao period in the study area to estimate the wood consumption of houses built in Zhengzhou during this period. Combining the above two approaches, this study explores the relationship between plants, architecture, and human activities in Zhengzhou in the Late Yangshao period, as well as the history of land use. The results are as follows: (1) After 4.9 ka BP, the number of trees and shrubs such as Pinus (falling from 58.8% to 46.9%) decreased rapidly, and the number of herbaceous plants increased. (2) Excluding the influence of the Holocene climate change, the large-scale decline in trees and shrubs in the region is likely to have been human-driven. The number of excavated houses in 11 of the 236 Late Yangshao sites in the Zhengzhou area reached 362, while the minimum wood consumption reached 1270.62 m3. In addition, the rapid expansion of the population size and the large-scale development of new arable land and forest clearance in the Late Yangshao period show that humans had a strong influence on the surrounding vegetation and land cover/use. The trend of regional deforestation was so obvious and irreversible that the inhabitants had to adopt techniques using less wood or no wood to build houses during the subsequent Longshan culture period.

Lateglacial and Holocene glacier variations in an active volcanic area, northern Jan Mayen (Nord‐Jan), Norway

Jan Mayen is a volcanic island situated 550 km NE of Iceland. It has been shown previously that the island and probably also shallow shelf areas around it were covered by a contiguous ice cap during the last glaciation. Today, active glaciers exist only in the northern part of the island around the Beerenberg volcano. Until now, information on Lateglacial and Holocene glacier and environmental variations has been sparse. We focus on the northern part (Nord‐Jan), discussing glacier evolution and environmental changes from the Lateglacial to the Holocene. Widespread volcanic activity during the postglacial era resulted in lava flows and volcanic craters amidst glaciogenic deposits, complicating glacial and environmental reconstructions. We suggest that the ice cap covering Jan Mayen separated into two (northern and southern) approximately 20 ka ago, based on observations from glacial striae and terrestrial cosmogenic nuclide exposure dating. Deglaciation of the southern flank of the Beerenberg ice cap was accelerated by initial subglacial volcanic activity, which probably rapidly evolved to protrude above the glacier surface. Subsequently, around 18.9 ka, vertical melting and ice‐marginal recession intensified in Nord‐Jan. A relatively warm period followed thereafter, evidenced by organic material giving a calibrated age of 17 to 16 cal. ka BP. The extent of deglaciation during this period is unknown as the dated material was found redeposited in lake sediments. Several cosmogenic exposure ages from bedrock and glacial erratics correspond to the Lateglacial period. The interpretation of these ages is not obvious, but we favour a hypothesis involving a Lateglacial readvance of the glaciers when lateral moraines were also deposited. Mild conditions, characterized by plant growth and soil formation, prevailed during the Early Holocene. During this period, the lateral moraines formed during the Lateglacial probably disintegrated, leaving only the remnants visible today.