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Copyright of Relaciones de la Sociedad Argentina de Antropología is the property of Sociedad Argentina de Antropologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An intertidal sandstone reef, named barra de Las Canteras, protects the western coast of Las Palmas de Gran Canaria city (Canary Islands, Spain). The beach-reef system of Las Canteras constitutes one of the most valuable coastal geomorphological sites in the archipelago. Stratigraphic studies have identified the formation of the reef in the Last Interglacial (MIS 5e) in a coastal sedimentary paleo-environment. The rock structure is highly exposed to the Atlantic swell and consists mainly of a sandstone beachrock with a medium resistance to erosional processes. However, the historical and current erosion rates and the original extent of the reef are not known to date. This paper explores the geomorphological structure of the reef by combining a topo-bathymetric analysis (obtained by differential GPS, multibeam echosounder and hyperspectral sensor) and the analysis of geomorphological features on high-resolution images, obtained with a hyperspectral camera mounted on a UAV. The results provide a comprehensive, high-resolution image of the subaerial and submerged morphology of the reef. The structure reflects the distribution of erosional fronts and the existence of collapsing submarine blockfields and nearshore, uneroded, remnant reliefs. Detailed analysis of these features allows to estimate the probable original extent of the sandstone reef and to relate the erosional retreat processes to the sea-level dynamics during the Holocene. [ABSTRACT FROM AUTHOR]

In this paper, we apply standard zooarchaeological methods and novel osteological approaches to analyse faunal remains from five Middle– Late Holocene sites in the southern Tibetan Plateau (STP). Framed by direct radiocarbon dates on taxonomically classified bioarchaeological remains and compared with published palaeoclimate data, our findings revealed a three-stage process of agro-pastoral development in the STP ca. 5.5 to 1.0 ka. In the first phase, habitation was restricted to the lower southeastern part of the plateau and human subsistence essentially based on foraging and low-level pig–millet farming. With the onset of colder and drier climatic conditions ca. 3.8 ka, the study area witnessed a growing human presence at higher elevations in its central and western parts, together with a shift towards bovid husbandry and barley cultivation, that is, agricultural practices that originated in west Asia; these were likely introduced to the STP following the eastern margin of the TP and/or arrived by sub-Himalayan transfer. Climate and ecological degradation might have contributed to the decline of local game in favour of cold-and-dry-tolerant pastoral livestock and crops. Our work shows that Middle–Late Holocene climate change, ecological change, human subsistence shifts, and prehistoric cultural transmissions are intimately connected. [ABSTRACT FROM AUTHOR]

The paper explores the thermodynamic properties of primordial black holes (PBHs) in the braneworld. Specifically, the researchers examined Hawking radiation and the lifetime of PBHs. Through their analysis, an exact analytical expression for the Bekenstein–Hawking entropy, temperature, and heat capacity was derived. Their findings suggest that the lifetime of PBHs in the early universe is reduced by at least one order of magnitude, ultimately leading to their evaporation. This could explain why we have not observed the final rapid evaporation of PBHs in the recent epoch of the universe. [ABSTRACT FROM AUTHOR]

On timescales longer than the solar cycle, long-term changes in CO 2 concentration and geomagnetic field have the potential to affect thermospheric dynamics. In this paper, we investigate the thermospheric dynamical response to these two factors during the Holocene, using two sets of ∼12000 -year control runs by the coupled thermosphere–ionosphere model, GCITEM-IGGCAS. The main results indicate that increased/decreased CO 2 will enhance/weaken the thermospheric circulation throughout the Holocene, but this effect is non-linear. The cooling effect of CO 2 in the thermosphere further provides plausible conditions for atmospheric tidal propagation and increases the thermospheric tidal amplitude. Geomagnetic variations induce hemispheric asymmetrical responses in the thermospheric circulation. Large changes in the circulation occur at high latitudes in the hemisphere with distant magnetic pole drift, inferring a crucial role of geomagnetic non-dipole variations in circulation changes. A positive correlation between the diurnal migrating tide (DW1) and geomagnetic dipole moment is revealed for the first time. The amplitude of DW1 in temperature will increase by ∼1 –3 K for each 1×1022 A m 2 increase in dipole moment. [ABSTRACT FROM AUTHOR]

Copyright of Arid Land Geography is the property of Chinese Academy of Sciences, Xinjiang Institute of Ecology & Geography and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Over recent epoch, initial uplink synchronization has become an essential part of the wireless communication systems owing to its amenities in the identification of new users to originate communication. Yet, allocating and sharing resources to users is a bottleneck due to the interference caused by multiple users. Besides, preceding works didn't concentrate on the usage of an effective mechanism to estimate the parameters of the received signal in the multiuser synchronization environment. These downsides affect the throughput and spectrum efficiency of the designed OFDMA system. To address these bottlenecks, this paper proposes the Joint Initial Uplink Synchronization and Interference Aware Resource Allocation (JIUS-IRA) in the Multi-User OFDMA system. JIUS-IRA comprises four processes: Parameter Estimation, Optimum Antenna Selection, Resource Allocation, and Resource Sharing. Initially, JIUS-IRA executes the Fast Block Least Mean Square-based Parameters Estimation Scheme (FBLMS-PES) to estimate the user parameters. To reduce the power consumption during transmission between 5G MIMO base station and users, JIUS-IRA selects the optimal antenna for transmission. The Sign Rank Oriented Resource Allocation (SO-RA) method is executed to allocate sub-channel resources to the cellular user. The resource requirement of D2D users present in the OFDMA system is resolved via the Harris Hawks Optimizer based Resource Sharing Scheme (H2ORSS). The numerical results acquired from the simulation are highly confidential with regard to metrics Root Mean Square Error (RMSE) of timing estimation (∼0.006), RMSE of power estimation (∼0.0079), RMSE of frequency estimation (∼ 0.008), Throughput (∼95%), Spectrum Efficiency (∼11.9 bps), and Complexity (0.045 × 104). [ABSTRACT FROM AUTHOR]

Africa, the cradle of human evolution, has one of the largest and most diverse rainforests in the world. The African rainforests contain evidence of human occupation as well as fluctuating climate during the Pleistocene; such evidence offers archaeologists and palaeoecologists the opportunity to understand how climatic fluctuations have influenced human behaviour. However, compared to the rainforests environments in Asia and South America, the human ecological history of those in West-Central Africa is poorly understood. This is because of comparatively fewer scientific programmes which synergize palaeoecological and archaeological data and thus could enhance the knowledge and allow for an evaluation of the impact of climatic fluctuations on human behaviour in the rainforests of West-Central Africa during the Pleistocene and Holocene periods. The goals of this paper are twofold, namely: (i) to provide a synthesis of the past climatic variability in the rainforests of West-Central Africa, and (ii) to demonstrate the influence of such variability on human behaviour during the Pleistocene to Holocene periods. It is hoped that this paper will stimulate Africanists to adopt an inclusive scientific anthropological and palaeoecological approach in understanding human–climate interactions in the West-Central African rainforests. This article is part of the theme issue 'Tropical forests in the deep human past'. [ABSTRACT FROM AUTHOR]

This paper presents new data on the spatial organization of mound-builder groups in the India Muerta wetlands, Uruguay. This area presents the beginning of land architecture in the region (ca. 4800–5000 years BP), associated with more arid climate. This construction tradition continues and intensifies, mainly from ca 3000 years BP, from the establishment of warmer and damper conditions. New sources of information and geospatial technologies have made it possible to locate mound sites with greater precision, as well as to analyze settlement patterns. Indigenous communities occupied areas of hills, plains and wetlands, showing differences but also regularities in spatial organization in each area. In the whole area, earthen mound complexes form groups of different orders, from regional to domestic units, configured by mounds, negative structures and limited spaces. The location of the mounds is primarily in dry areas, known locally as islands, which are prominent in the landscape during floods in this wetland-dominated environment. Through this analysis of the landscape, this work delves into the underlying logic of the social construction of the territory. The results achieved in this paper are consistent with previous research suggesting planned occupation associated with villages integrated within broader regional systems. [ABSTRACT FROM AUTHOR]

The interpretations of unusual or special archaeological contexts in the Near Eastern Neolithic that might suggest the appearance of the first forms of religious belief in early sedentary communities have commonly been associated with magic practices or other concepts related to ritual performance or symbolism. The present work proposes alternative perspectives that focus on the term "sacred" as outlined by three renowned anthropologists: Girard, Durkheim and Eliade. This paper also discusses interpretative views on the development of symbolic and ritual forms in early Holocene societies in the Near East. It is argued that the sacred in the Neolithic is an externally manifested prosocial reality that is gradually adopted via mimetic practices. A number of Neolithic archaeological examples will be presented and analysed in light of mimetic theory and other key anthropological concepts. [ABSTRACT FROM AUTHOR]

Despite extensive research on alluvial architecture, there is still a pressing need for data from modern fluvio-deltaic environments. Previous research in the fluvial-dominated proximal and central Rhine–Meuse delta (the Netherlands) has yielded clear spatial trends in alluvial architecture. In this paper, we include the backwater length to establish architectural trends from apex to shoreline. Channel-belt sand body width / thickness ratios and interconnectedness were determined, and the proportions of fluvial channel-belt deposits, fluvial overbank deposits, organics and intertidal deposits were calculated for the complete fluvio-deltaic wedge based on high-resolution geological cross sections. It was found that the average width / thickness ratio of channel-belt sand bodies in the proximal delta is 5 times higher than in the distal delta. Other down-valley trends include an 80 % decrease in the channel deposit proportion (CDP) and a near-constant proportion of overbank deposits. Additionally, interconnectedness in the proximal delta is 3 times higher than in the distal delta. Based on the Rhine–Meuse dataset, we propose a linear empirical function to model the spatial variability of CDP. It is argued that this relationship is driven by four key factors: channel lateral-migration rate, channel-belt longevity, creation of accommodation space and inherited floodplain width. Additionally, it is established that the sensitivity of CDP to changes in the ratio between channel-belt sand body width and floodplain width (normalized channel-belt sand body width) varies spatially and is greatest in the central and distal delta. Furthermore, the proportion of fluvial channel-belt sands is generally an appropriate proxy for the total sand content of fluvio-deltaic successions, although its suitability as a total sand indicator rapidly fades in the distal delta. Characteristics of the backwater zone of the Rhine–Meuse delta are (1) sand body width / thickness ratios that are lower as a consequence of channel narrowing (not deepening), (2) a rapid increase and then a drop in the organic proportion, (3) an increase in the total sand proportion towards the shoreline, and (4) a drop in the connectedness ratio. For this paper, unique high-resolution quantitative data and spatial trends of the alluvial architecture are presented for an entire delta, providing data that can be used to further improve existing fluvial stratigraphy models. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the University of Latvia. History / Latvijas Universitātes Žurnāls. Vēsture is the property of University of Latvia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper develops a composite absolute paleointensity record for Holocene paleomagnetic secular variation (PSV) from central North America. Twelve full‐vector (inclination, declination, paleointensity) PSV records were assessed in order to build the composite record. Nine of the paleointensity records come from sediment paleomagnetic studies and are considered relative in intensity. Three of the paleointensity records come from absolute paleointensity measurements of archeological materials and lava flows. This paper develops a new method to normalize the sediment relative paleointensity records to the absolute intensity records. The final composite paleointensity record describes intensity variability over a region of Central North America delineated by 35°–48.6°N and 240.4–291.4°E (∼14° × 50°). This composite record shows a distinctive long‐duration (∼104 year) oscillation and a series of millennial‐scale intensity oscillations that are consistent over our study region. Plain Language Summary: This study develops a composite record of geomagnetic field intensity for the central North America for the last 8,000 years. This record is important for considering the total geomagnetic field variability I this region and its dynamo source(s). Key Points: We develop a new composite absolute paleointensity record for Holocene Central North AmericaWe develop a new renormalization technique to combine absolute paleointensity records and sediment relative paleointensity recordsThe final composite absolute paleointensity record has a distinctive long‐term trend and millennial‐scale variability [ABSTRACT FROM AUTHOR]

In the field of botany applied to archaeological and palaeoecological studies, the multi- and inter-disciplinary nature of this research produces a lack of data sharing and scattered articles in the specialty literature or in national and international journals. The vast production of archaeobotany and palynology data makes it necessary to develop a tool for the availability, accessibility, and dissemination of existing research. Many databases exist on palaeoecology, archaeobotany or pollen data. There are no collections focused on archaeological sites and human-induced environments and centred on Southern Europe and the Mediterranean. BRAIN - Botanical Records of Archaeobotany Italian Network is the first database listing sites from which all types of plant records are available in Italy and nearby Mediterranean regions. BRAIN represents the largest integrated collection of archaeo/palaeo-botanical data and a range of descriptive information that makes data recovery FAIR ready. This unique network hosts data on the availability of anthropogenic pollen, palynomorphs and plant macroremains in the same database, and experts of different research fields may contribute to it. [ABSTRACT FROM AUTHOR]

The adoption of more sedentary residential practices is a long process in which groups shift in size, permanence, makeup, and even location in response to the social, demographic, ecological, and subsistence pressures associated with settling down. Coastal peoples living in the Southeast U.S. are among the first to adopt more sedentary lifeways in North America as evidenced by their creation of dozens of large circular or arcing shell middens during the end of the Middle Holocene and start of the Late Holocene. Relying on material culture studies and AMS radiocarbon data refined using Bayesian statistical modeling, we investigate the sequential establishment and abandonment of three village sites built over more than 300 years and located only a few kilometers apart. These studies reveal important insights into the process of adopting more sedentary practices in the region and how local communities adapted to associated pressures. [ABSTRACT FROM AUTHOR]

Recent climate and environment over the Tibetan Plateau (TP) have undergone significant changes, dominated by variations in the Westerlies and the Indian summer monsoon. However, long‐term shifts in atmospheric circulation during the transitional seasons are still lacking. Here we investigate the modern distribution of Tsuga pollen over the central‐western TP and confirm it as an indicator of variable atmospheric circulation in spring. By combining our Tsuga record from Taro Co with existing records in the Tsuga pollen source area, we suggest that a potential particle transport pathway from the southern slope of the Himalayas to the interior of the plateau appeared in the spring of the late Holocene. Our results show that the springtime atmospheric circulation over the southwestern TP during the early and late Holocene is closely related to the substantial remnants of ice sheets at northern high latitudes and the frequency of El Niño events, respectively. Plain Language Summary: The spring climate over the Tibetan Plateau (TP) is undergoing significant changes that yield profound impacts on environmental changes such as variations in vegetation phenology and alpine treeline. Knowledge of long‐term variations in atmospheric circulation during spring can improve the understanding of current climatic and environmental change and the projection of future variability. In this paper, we use an exotic pollen grain, which can be transported long distances in the air, as an indicator to trace the variability of spring atmospheric circulation over the TP. The results indicate that the spring meridional atmospheric circulation from the southern slope of the TP to its interior has been enhanced in the last four thousand years, which is mainly influenced by the frequency of El Niño events. Key Points: Spring atmospheric circulation change over the southwestern Tibetan Plateau (TP) during Holocene is reconstructedMeridional atmospheric circulation in spring over the southwestern TP is strengthened in the late HoloceneHigh‐(low‐) latitude forcing mainly influence the variations in spring atmospheric circulation during the early (late) Holocene [ABSTRACT FROM AUTHOR]

The Wudaoliang–Changshagongma fault is one of the NW-trending faults located within the southern Bayan Har Block of the Tibetan Plateau in China. In this paper, we used high-resolution imagery and digital elevation model data to study the geomorphological and geological characteristics of the fault. Furthermore, the result also determined the fault trace and estimated the average horizontal slip rate of the fault since the late Quaternary to have been 2.6 ± 0.6 mm/a. This slip rate is approximately equivalent to that of the Awancang, Madoi–Garde, and Dari faults, which are also located within the block. Furthermore, the slip rates of these faults obtained by remote sensing and geological methods are consistent with GPS observations. It indicates that tectonic deformation within the block is continuous and diffuse. Using trenching study results and sedimentary radiocarbon dating, we identified four paleoearthquake events that occurred at 42,378–32,975, 33,935–20,663, 5052–4862, and after 673–628 cal BP, respectively. The recurrence intervals of large earthquakes on the faults within the block are much longer than those of the boundary faults, and the slip rates are also smaller, indicating that faults within the block play a regulatory role in the tectonic deformation of the Bayan Har Block. [ABSTRACT FROM AUTHOR]

Copyright of Disasters is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper examines patterns of human–environmental interactions across northern Asia during the Holocene, in order to summarize current knowledge and identify key areas for future research. To achieve these goals, currently available chronological, cultural, and paleoenvironmental datasets from the east Russian Arctic for the last 10,000 14C years were integrated. Study regions include the Taymyr Peninsula, Lena River basin (except its southern part), northeastern Siberia, and Kamchatka Peninsula. Several broad-scale correlations between climatic fluctuations and cultural responses (e.g., subsistence strategies and occupation densities) were identified; however, these are not straightforward. For example, the increase of occupations during the warm periods in the Early–Middle Holocene are notable while the most pronounced rises coincide with a cooling trend in the Late Holocene. This shows that the human–environmental relationships in the Holocene were not linear; more interdisciplinary research will be needed to construct higher resolution data for understanding prehistoric cultural responses to past environmental changes in the Asian Arctic. [ABSTRACT FROM AUTHOR]

The Jizera River in Czechia is a typical mid‐sized Central European watercourse. Its floodplain shows a morphological contrast between the laterally stable low‐sinuous current channel and preserved palaeomeanders. The aim of this paper was to date and explain the obvious metamorphosis of the channel pattern from meandering to low‐sinuous. We analysed the morphology of the lower river reach using a digital terrain model (DTM) and historical maps from the 1840s. Furthermore, the floodplain architecture was described based on the DTM, geophysical imaging (ground penetrating radar, GPR), sediment lithology and anthropogenic contamination using geochemical proxies, and optically stimulated luminescence (OSL) dating. The geochemical proxies were processed using log‐ratio methods from the compositional data analysis toolbox. According to our results the Jizera River showed signs of systematic lateral floodplain reworking during the Late Holocene with only minor aggradation, although parts of the catchment are covered by easily erodible loess. Interestingly, vertical aggradation did not show a significant increase during the last millennium. In the main study area, this limited vertical aggradation resulted in the preservation of palaeomeander fragments and palaeochannel belts with 100–200 m mean width in the 300–600 m wide floodplain, which are recognisable in the topography and in subsurface GPR imaging. This channel meandering took place between around 4 and 1.2 ka, and the transition towards the laterally stable modern channel with low sinuosity occurred around 1.2 ka. This timing indicates a climatic rather than anthropogenic impact, which was rather weak around that time. One likely cause for this transition was the influx of material from ravines incised into the sandstone valley edges during past climatic extremes. Subsequently, the re‐establishment of a meandering pattern was possibly prevented by a combination of low fluvial activity and the construction of weirs that reduced stream power. [ABSTRACT FROM AUTHOR]

Long considered on the margins, far from the major cultural traditions, the Sechura Desert is situated at the crossroads between the cultures of southern Ecuador and those of the northern Peruvian coast and preserves a large number of varied archaeological sites. Despite this evidence, little is known about the societies that inhabited this region during the Holocene. Exposed to natural hazards, including El Niño events, and to major climatic changes, they were able to adapt and exploit the scarce resources that this extreme environment offered them. Because of this rich history, we have been conducting archaeological research in this region since 2012 in order to clarify the dynamics of human occupation and their links with climate oscillations and environmental changes. This paper present the results of a multidisciplinary study of Huaca Grande, a mound located on Nunura Bay, 300 m from the Pacific Ocean. The nature of the human occupations at Huaca Grande was varied, and several adjustments occurred over time. The subsistence economy was based mainly on local marine resources and a continual use of terrestrial vegetal resources. However, a major change occurred in the more recent occupations, with the apparition of non-local resources (maize and cotton) indicating that Huaca Grande was connected to trade networks. The results show two main phases of occupation separated by a long abandonment (mid-5th century CE to mid-7th century CE and mid-13th century to mid-15th century CE). The occupation of the site appears to have been influenced by changes in the local climate and by extreme El Niño events. Our results highlight the great adaptability of these human groups over the span of a millennium and their capacity to react to the climatic changes and hazards that characterise this region. [ABSTRACT FROM AUTHOR]

The Pampas deer (Ozotoceros bezoarticus) is an endangered ungulate from South American. The following paper presents the first investigation on the isotopic ecology (δ13Ccollagen; δ15Ncollagen) of modern populations of Pampas deer. The information obtained is compared with new δ13C and δ15N data of Pampas deer bones recovered from archaeological sites in the Central Pampean Dunefields (Inland Pampa phytogeographic area) and with previously published archeofaunistic isotope data for sites from eastern central Argentina. The range of δ13C values of Pampas deer is broad, ranging from a diet dominated by C3 plants to a mixed diet of C3 and C4 plants. The δ15N values mainly show distinct signals between the Atlantic coast and the interior. The diet breadth of the Pampas deer suggests a high adaptability to different environments, a crucial factor for conservation programs of this species. The δ13C values of the Inland Pampa do not show great differences between the Middle Holocene, Late Holocene and today. Adaptation strategies of the Pampas deer to the environmental changes during the Holocene were not associated with a modification of their feeding habits, but rather with social and demographic strategies. These variations in ecology conditioned the predictability of this prey for hunter-gatherers. [ABSTRACT FROM AUTHOR]

Bioarchaeological research of bone growth patterns provides information on the health status and disease of past populations. Recent studies have pointed out the potential of metric analysis of nonadult vertebrae as indicators of stress during different stages of ontogeny, highlighting that most vertebral measurements present low sexual dimorphism, a stable and known pattern of growth and give useful information even in incomplete spines. The aims of this paper are first, to construct a vertebral growth profile for nonadults of a skeletal series of Patagonian Late Holocene hunter‐gatherers from Salitroso Lake (SAC); second, to compare it to the ones obtained in other archaeological and modern populations with different stress experiences; and third, building on this, to assess whether individuals with evidence of stress experienced in early development demonstrate different patterns in vertebral growth than those without. Two spinal dimensions are used: vertebral body height (VBH) and transverse diameter of the neural canal (TDNC) in a sample of 23 nonadult skeletons with ages previously estimated from dental and bone indicators. The vertebral dimensions of 20 adults between 18 and 35 years of age were also measured as reference information. Results show that the growth of the VBH is steady over the years and reaches adulthood size by approximately 16 years of age whereas TDNC dimensions do not experience marked fluctuations in size throughout life and adult dimensions are reached at approximately 4 years of age as expected. The vertebral growth pattern observed in SAC is similar to that obtained in other archaeological samples from very different settings but experiencing relatively high nutritional or pathological stress in early stages of life. However, it is markedly different, and systematically smaller, to the 20th century sample pattern, probably responding to a secular trend in the modern population with a more stable access to resources and medical treatment. Finally, SAC individuals with systemic stress markers do not tend to exhibit smaller vertebral dimensions than those without them. [ABSTRACT FROM AUTHOR]

Global atmospheric warming is causing physical and biotic changes in Earth's high mountains at a rate that is likely unprecedented in the Holocene. We summarize changes in the presently glacierized mountains of northwest North America, including a rapid and large reduction in glacier ice and permafrost, a related increase in slope instability and landslides, river re-routing and other hydrological changes, and changing aquatic ecosystems. Atmospheric greenhouse gas concentrations continue to rise and will likely do so for at least the next several decades, if not longer, and mountains will continue to warm, perhaps reaching temperatures up to several degrees Celsius warmer than present over the remainder of this century. As a result, the rate of physical and biotic changes documented in this paper is very likely to dramatically increase and transform high-mountain environments. [ABSTRACT FROM AUTHOR]

Mercury accumulation in lake sediments has been extensively studied with regard to anthropogenic signals, but natural processes controlling mercury accumulation in the past and the influence of environmental and climatic changes are still poorly understood. In this study we present a 17 300 years old record of mercury accumulation in lake sediments in combination with a multi-proxy investigation of climatic and environmental changes in Southernmost Patagonia (53° S). Mercury accumulation in the remote pristine lake has been highly variable (up to a factor of 16), clearly exceeding the anthropogenic forcing of atmospheric mercury fluxes (factor of 3-5). Statistical data evaluation based on Principle Component Analysis reveals that the dominant driver of variations in mercury accumulation along with other organically bound elements (e.g. copper and yttrium) has been leaching of soluble organic complexes from catchment soils. This indicates that changes in precipitation rates and soils leaching are the most important climatic driver for short term variations in mercury in the lake's sediments. In the long term, however, mercury accumulation rates remain relatively constant (29 µgm-2 yr-1). This reflects that mercury accumulation in the catchment soils through atmospheric deposition and bedrock weathering has been fairly constant, too. As carbon storage in the soils and transport into the lake have increased, Hg/C ratios in the soil OM decreased. Fluxes of Hg into the lake are therefore mainly determined by the amount of OM leached into the lake and its Hg/C ratio. [ABSTRACT FROM AUTHOR]

Four cores from Balkans lakes Ohrid and Prespa were studied for recognition of tephra layers and cryptotephras, and the results presented along with the review of data from other two already published cores from Lake Ohrid. The six cores provide a previously unrealised tephrostratigraphic framework of the two lakes, and supply the first detailed tephrochronologic profile (composite) for the Balkans, which spans from the end of the Middle Pleistocene to the end of the Ancient Age (AD 472). A total of 12 tephra layers and cryptotephras were recognised in the cores. One is of Middle Pleistocene age (131 ky) and correlated to the marine tephra layer P-11 from Pantelleria Island. Eight volcanic layers are Upper Pleistocene in age, and encompass the period between ca. 107 ky and ca. 31 ky. This interval contains some of the main regional volcanic markers of the Central Mediterranean area, including X-6, X-5, Y-5 and Y-3 tephra layers. The other layers of this interval have been related to the marine tephra layers C20, Y-6 and C10, while one was for the first time recognised in distal areas and correlated to the Taurano eruption of probable Vesuvian origin. Three cryptotephras were of Holocene age. Two of which have been correlated to Mercato and AD 472 eruptions of Somma-Vesuvius, while the third has been correlated to the FL eruption from Mount Etna. These recognitions provide a link of the Ohrid and Prespa lacustrine successions to other archives of the Central Mediterranean area, like South Adriatic, Ionian, and South Tyrrhenian Seas, lakes of Southern Italy (Lago Grande di Monticchio, Pantano di San Gregorio Magno and Lago di Pergusa) and Balkans (Lake Shkodra). [ABSTRACT FROM AUTHOR]

GIS data processing techniques are currently being used to revise many ideas in the field of geomorphology and related sciences. The paper presents the characteristics of the landform relief of the Mroga and Mrożyca interfluvial area (on the northern margin zone of the Łódź Plateau) based on the results of GIS spatial analysis models. These are techniques that have not been used so far for such a detailed fragment of the Łódź Plateau. The aim of this paper was to show the possibility of detailing topographic and geomorphological analysis and re-imagining the features of the Łódź Plateau relief on the example of a case study of the Mroga and Mrożyca interfluvial area. In this case, the use of GIS modelling confirmed the main features of the strongly transformed relief of the Mroga and Mrożyca interfluvial area, which is a result of overlapping elements of relief formed during the Warta stadial of the Odra Glaciation and further, during periods of the Vistulian and Holocene morphogenesis. [ABSTRACT FROM AUTHOR]

This paper presents new data on Oligocene–Quaternary deposits, recent (Neogene–Quaternary) structures, and active faults of the northern side of the Ubsunur Basin at its boundary with the Tannu-Ola Ridge, based on structural interpretation of remote sensing (RSD) and field data (2020–2021), including trenching of active faults. Two parageneses of faults of different geological natures and structural and relief-forming significance were identified in the north of the Ubsunur Basin. The first paragenesis presented by the covered North Ubsunur thrust and related deformations that developed during Neogene–Quaternary and which formed the boundary of the depression and the mountain uplift. The second paragenesis includes the South Tannuol and Erzin-Agardag faults, which cut structures of the first paragenesis; these faults were being active in the Late Pleistocene and Holocene. [ABSTRACT FROM AUTHOR]

Copyright of Archaeologia Baltica is the property of Archaeologia Baltica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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At present, there remains uncertainty surrounding the Younger Dryas-early Holocene glacial history of the Fennoscandian Ice Sheet in northwest Arctic Russia. This stems from a lack of high-resolution ice sheet-scale geomorphological data in the region. To address this, this paper presents 15,355 meltwater and morainic landforms in a new large-scale, glacial geomorphological map of the Younger Dryas-early Holocene ice marginal zone in the Republic of Karelia, northwest Russia. Individual landforms were mapped from relief-shaded renditions of the 2 m resolution ArcticDEM alongside 1 m resolution Esri World Imagery data in a Geographic Information System (GIS). The map, which is presented at a scale of 1: 675,000, will form the basis of a palaeo-glaciological reconstruction of northwest Russia that will inform on ice sheet dynamics – at both a regional- and ice sheet-scale – and provide an important framework through which numerical ice sheet models can be constrained. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study on fluctuations in the water level of the Curonian Lagoon (in the Baltic Sea). To date, the genesis of this inland bay as part of the complex postglacial development of the southeastern Baltic is poorly understood. The data from lithological, geochronological, and phytolith analyses, as well as assessments of plant and animal macroremains from the lagoonal sediments, provide a reconstruction of local coastal biocenoses and water level dynamics in the Middle and Late Holocene time. This study reveals the fairly dynamic evolution of the coastal zone of the Curonian Lagoon over the past 7000 years, as indicated by the traced succession of plant communities from forest to near-shore, open-water biocenoses and the alternations of the drying out and inundation of the area under consideration. Thus far, a connection with two stages of the Baltic Sea water level fluctuations has been traced: the regressional stage, which took place approximately 5600 cal years BP, and the Late Subatlantic transgression, which started at approximately 1100 cal BP. This study demonstrates that phytolith (microbiomorphic) analysis is a promising method for the study of temperate-latitude lagoonal sediments, providing information not only on the local plant communities, but also on the changes in the hydrological regime of the area. [ABSTRACT FROM AUTHOR]

This paper describes the instability of river channel systems in alpine rockslide deposits using the Fernpass Rockslide and the river Loisach in the Tyrolian Außerfern District (Austria) as an example of paleoenvironmental developments. This is the first investigation of this kind of the Fernpass, one of the most important Alpine north–south transport connections since the bronze age. It uses geomorphological, sedimentological, onomastic and hydrogeological investigations to reconstruct the course of a late Holocene river in this area and a probabilistic simulation for dating. Tracer tests assisted in investigating the potential groundwater connections of the river systems. The findings show that the Palaeoloisach runs on the orographically right side in a marginal valley of the Fernpass furrow and changes to the orographically left side of the furrow within the Rauth suburb in the village of Biberwier. A probabilistic simulation of the Narrenbichl slip event, which changed the course of the Palaeoloisach, dates the event to an age of 664 ± 116 BC. This investigation is an important contribution to understanding Quaternary postrockslide developments, how groundwater contributes to forming postrockslide channel systems and archaeological findings occurring in populated areas. [ABSTRACT FROM AUTHOR]

Variability is a commonly observed property of classical Be stars (CBe) stars. In extreme cases, complete disappearance of the H α emission line occurs, indicating a disc-less state in CBe stars. The disc-loss and reappearing phases can be identified by studying the H α line profiles of CBe stars on a regular basis. In this paper, we present the study of a set of selected nine bright CBe stars, in the wavelength range of 6200–6700 Å, to better understand their disc transient nature through continuous monitoring of their H α line profile variations for five consecutive years (2015–2019). Based on our observations, we suggest that four of the program stars (HD 4180, HD 142926, HD 164447 and HD 171780) are possibly undergoing disc-loss episodes, whereas one other star (HD 23302) might be passing through disc formation phase. The remaining four stars (HD 237056, HD 33357, HD 38708 and HD 60855) have shown signs of hosting a stable disc in recent epochs. Through visual inspection of the overall variation observed in the H α EW for these stars, we classified them into groups of growing, stable and dissipating discs, respectively. Moreover, our comparative analysis using the BeSS database points out that the star HD 60855 has passed through a disc-less episode in 2008, with its disc formation happening probably over a timescale of only two months, between January and March 2008. [ABSTRACT FROM AUTHOR]

Mangroves are among the world's most threatened ecosystems. Understanding how these ecosystems responded to past natural and anthropogenic drivers of ecological change is essential not only for understanding how extant mangroves have been shaped but also for informing their conservation. This paper reviews the available paleoecological evidence for Pleistocene and Holocene responses of Caribbean mangroves to climatic, eustatic, and anthropogenic drivers. The first records date from the Last Interglacial, when global average temperatures and sea levels were slightly higher than present and mangroves grew in locations and conditions similar to today. During the Last Glaciation, temperatures and sea levels were significantly lower, and Caribbean mangroves grew far from their present locations on presently submerged sites. The current mangrove configuration was progressively attained after Early Holocene warming and sea level rise in the absence of anthropogenic pressure. Human influence began to be important in the Mid-Late Holocene, especially during the Archaic and Ceramic cultural periods, when sea levels were close to their present position and climatic and human drivers were the most influential factors. During the last millennium, the most relevant drivers of ecological change have been the episodic droughts linked to the Little Ice Age and the historical developments of the last centuries. [ABSTRACT FROM AUTHOR]

Humanity's relationship with the environment during the Holocene, and into the Anthropocene, is structured around our dependance on agricultural production, which has resulted in risk mitigation strategies that include intensive landscape modifications, among other tactics. However, to understand broader patterns of human resilience and the shifts in human/environment relationships, we need to look further back in time. Through this paper, we explore cultural strategies of risk management and resilience in pre-Holocene communities and how these practices allowed hunter-gatherer communities to adapt to a changing environment. For over 1000 years, the Epipalaeolithic site of Kharaneh IV was a focal point on the landscape for hunter-gatherer groups, acting as an aggregation site for Early and Middle Epipalaeolithic peoples. Located in the eastern desert of Jordan, at the time of occupation the site was a lush wetland surrounded by a rich grassland environment, providing abundant food and other resources for the site's occupants. However, over time the wetland began to dry up and by 18,600 cal BP Kharaneh IV was abandoned. In this paper, we discuss the final occupation of Kharaneh IV, linking the site's abandonment to the increasing aridification of eastern Jordan. Environmental change led to the eventual abandonment of Kharaneh IV and other nearby sites, as people relocated within the Azraq Basin in search of new water resources during the Holocene. Flexible technological strategies and knowledge of the landscape created resilient cultural practices that allowed these communities to use population movement as a risk management strategy. [ABSTRACT FROM AUTHOR]

Drylands are diverse and dynamic ecosystems that have been occupied by humans throughout the Holocene. Nonetheless, drylands are often conceived of as marginal, rare, and inimical to human livelihoods. This Special Issue interrogates the interactions between humans and arid and aridifying environments to investigate how drylands offer unique risks and opportunities to their resilient inhabitants. This article introduces the 11 environmental archeology papers and 1 discussion paper in this Special Issue, the proceedings of a 2021 virtual workshop on the topics of risk and resilience. Each contribution explores a different geographic and chronological context around the globe. We also introduce three subthemes of this Special Issue: "Multi-Scalar Analysis," "Abundance and Diversity," and "Cascading Risks." Collectively, a key strength of the case studies in this volume is the range of environmental archeology methods and datasets that they showcase. These authors draw out details within a multi-scalar understanding of risk and risk perception in the particular contexts in which they work. As we face compounding contemporary risks associated with the global impacts of a changing climate, it is more important than ever to recognize the range of human relationships with aridification, and the dynamic, localized socio-environmental histories of drylands. [ABSTRACT FROM AUTHOR]

Evidence for the timing and pace of past grounding line retreat of the Thwaites Glacier system in the Amundsen Sea embayment (ASE) of Antarctica provides constraints for models that are used to predict the future trajectory of the West Antarctic Ice Sheet (WAIS). Existing cosmogenic nuclide surface exposure ages suggest that Pope Glacier, a former tributary of Thwaites Glacier, experienced rapid thinning in the early to mid-Holocene. There are relatively few exposure ages from the lower ice-free sections of Mt. Murphy (<300 m a.s.l.; metres above sea level) that are uncomplicated by either nuclide inheritance or scatter due to localised topographic complexities; this makes the trajectory for the latter stages of deglaciation uncertain. This paper presents 12 new 10 Be exposure ages from erratic cobbles collected from the western flank of Mt. Murphy, within 160 m of the modern ice surface and 1 km from the present grounding line. The ages comprise two tightly clustered populations with mean deglaciation ages of 7.1 ± 0.1 and 6.4 ± 0.1 ka (1 SE). Linear regression analysis applied to the age–elevation array of all available exposure ages from Mt. Murphy indicates that the median rate of thinning of Pope Glacier was 0.27 m yr -1 between 8.1–6.3 ka, occurring 1.5 times faster than previously thought. Furthermore, this analysis better constrains the uncertainty (95 % confidence interval) in the timing of deglaciation at the base of the Mt. Murphy vertical profile (∼ 80 m above the modern ice surface), shifting it to earlier in the Holocene (from 5.2 ± 0.7 to 6.3 ± 0.4 ka). Taken together, the results presented here suggest that early- to mid-Holocene thinning of Pope Glacier occurred over a shorter interval than previously assumed and permit a longer duration over which subsequent late Holocene re-thickening could have occurred. [ABSTRACT FROM AUTHOR]

This paper presents results of a specialized analysis applied to deposits reached at site 193 which was drilled during the 19th cruise of the drillship Glomar Challenger in the Pacific Ocean east of the Central Kuril Islands. These data can serve as a basis for the initial phase of future submarine tephrochronologic surveys in the area. Special attention was paid to layers, lenses, and spots of tephra of varying composition and thickness, as well as to sediments having a higher admixture of volcanic glass particles. It was found that at least 8 ashfalls have occurred in the area of site 193, of which 7 took place during the last 115 ka. It is shown that these were more likely related to large and caldera-generating explosive eruptions at volcanic centers in the Kuril Islands. Preliminary dating of these has been carried out. For the first time, a core sample was identified to contain turbidite due to a hypothetical submarine earthquake that occurred in the Early Holocene. We suggest a hypothesis to explain why the sea sediment core samples are disrupted, hypothesizing that thick interbeds of water-rich pyroclastic material of aleuropelite dimension were converted to hydrosols by thixotropy. [ABSTRACT FROM AUTHOR]

During the Late Pleistocene (MIS 5e-2), the brown bear Ursus arctos was widespread in the Czech Republic. From this time interval, the species was recorded in 51 Czech localities, including 10 open-air and 41 cave sites. A total of 18 radiocarbon dates obtained from the material showed the presence of the species in this territory 46–12.6 kyr ago during the Late Pleistocene, but most of the dates are concentrated between 45.7 and 29.3 kyr. Later, its occurrence continued into the Holocene. Three dates confirmed the presence of U. arctos just before and during the LGM. However, during the coolest part of the GS-2.1b interval (about 20.9–19.0 kyr), the species was not recorded in the territory of the Czech Republic. A large, broad-toothed, highly carnivorous priscus ecomorph adapted to live in open grasslands occurred during the Late Pleistocene, while the arctos ecomorph was rarely recorded from that period. The post-LGM time (17.5–14.7 kyr) was characterised by increasing numbers of brown bear dates on the territory of the Czech Republic. It was also a period of progressive afforestation and the disappearance of the priscus ecomorph. The latest occurrence of the priscus ecomorph in the territory of the Czech Republic was represented by a robust mandible from the Býčí skála Cave, dated at 15.4–14.9 kyr. [ABSTRACT FROM AUTHOR]

This paper reports on the most ancient unusual morphological trait of the apertures of Poaceae pollen found in archaeological layers. In Poaceae, high levels of hybridization, polyploidy, apomixis, and multiporate pollen are often related. Multiple genomes in polyploids are critical for the adaptation of plant species to stresses and could be revealed by anomalies in pollen development. Therefore, the paleoenvironmental research can gain great benefits from identifying polyploids in past contexts by observing anomalous pollen morphology during pollen counts. The occurrence of multiporate pollen in Poaceae has also been related to special features of the ecology of the species showing this anomaly, as well as to climatic and environmental stresses experienced by Poaceae living in a given region. Multiporate and bi- or tri-porate instead of monoporate pollen grains have been observed in samples taken from Takarkori rockshelter, an archaeological site in southwestern Libya (central Sahara) that has been occupied between ~10,200 and ~4650 cal BP. Multiporate pollen was found in organic sands and coprolites of ovicaprines. On the basis of archaeobotanical research, this work aims to investigate whether the presence of supernumerary pores in Poaceae pollen may be an effect of both climatic/hydrological changes and continued anthropogenic pressure on the wild grasses living in the region. The presence of multiporate pollen reveals that Poaceae that lived in central Sahara tackled several kinds of stress during the early and middle Holocene. The Takarkori pollen record suggests that climate change could have played a major role in the early Holocene, while human pressure became stronger during the middle Holocene. The change in environmental conditions determined adaptive responses of polyploid grasses even in the form of multiporate pollen. [ABSTRACT FROM AUTHOR]

Current knowledge about the biogeographic patterns of biodiversity is based mostly on taxonomic diversity, which is typically measured as the number of species or higher taxa. In this paper I analyze 26 previously published Holocene lake core pollen records in order to assess how the morphological diversity of angiosperm pollen grains varies with latitude on a transect that includes eastern North America and the Neotropics. This represents a step toward understanding the evolution of plant morphology in a biogeographical context. I employ a system of eight discrete characters to describe first-order features of angiosperm pollen morphology and use algorithms written in the Python programming language to assess their morphological diversity. There is no statistically significant relationship between taxonomic diversity and morphological diversity in the samples of Holocene angiosperm pollen investigated here. The number of pollen morphotypes in the sediment samples investigated here increases from high latitudes to the tropics, but the highest morphological diversity occurs at high latitudes, and the lowest morphological diversity occurs at mid-latitudes around 40–50 ° N. At the biome level, there are peaks in morphological diversity at low and high latitudes with a trough in mid latitudes. There is evidence of high levels of pollen morphotype endemism in the tropical biome, and further work on how the volume of morphological space varies with latitude is needed in order to understand whether taxa in species-rich tropical ecosystems are more densely packed into morphological space. [ABSTRACT FROM AUTHOR]

An Erratum to this paper has been published: https://doi.org/10.1134/S1028334X23070164 [ABSTRACT FROM AUTHOR]

The paper presents a new high-resolution (up to decadal) palaeoecological evidence based on detailed AMS radiocarbon dating, plant macrofossils, testate amoebae, loss on ignition, peat humification, elemental and stable isotopic records, obtained from a palsa peatland located in vicinities of Igarka town. This gave us a unique possibility to examine the mid-to late Holocene environmental changes in a poorly investigated area in Yenisei Siberia. The obtained data show that the peatland initiation occurred at about 6350 cal yr BP by paludification of a larch forest in the conditions of climate warming and high surface wetness, possibly, due to permafrost thaw. The first sign of palsa formation occurred about 5360 cal yr BP and coincided with the temperature decrease, wetter and anoxic conditions in peatland. After several phases of uplifts (and relatively dryer conditions) and partial thawing and subsidence of its surface (wetter conditions) between 5360 and 2250 cal yr BP, the continuous rise of the perennial frost mound (up to the height of 5 m) accomplished by drying its surface and colonization by drought-resistant plant species, evidently, encouraged by the climate cooling and permafrost aggradation during the last two millennia. The high-resolution analyses of elemental (C and N) and stable isotope content (δ13C and δ15N) of the peat sequence revealed the strong linkages between the plant composition and mineralization/humification processes. Our multi-proxy study revealed detailed features of peat accumulation patterns driven by multiple interrelated allogenic and autogenic forcings, influencing changes in peat macroelement content and stable isotope composition. [ABSTRACT FROM AUTHOR]

In this paper, we explore and integrate different currencies that may underlie large-game hunting to guide a trans-Holocene analysis of variation in artiodactyl utilization using massive archaeofaunal data-sets from predominantly open-air sites from the Bonneville and Wyoming basins. The available empirical data continue to suggest that artiodactyls yield consistently higher return rates than lagomorphs allowing us to leverage predictions from both the prey choice and energetic risk-gain models that the relative importance of artiodactyl hunting should scale closely with climate-based change in their abundance on the landscape. We document with modeled climate data that seasonal variables correlated with the relative frequency of artiodactyl hunting, but that summer temperature had a significant overriding effect in both regions. Controlling for the negative relationship between summer temperature and artiodactyl abundances, we then document enhanced artiodactyl hunting in general and bison more specifically during the Fremont period that is consistent with a costly signaling hypothesis and the unique socio-ecological conditions of this context. Thus, climatic variation and its influence on artiodactyl abundances drives the overall trajectory of Holocene large game hunting variation but measurable and more subtle influences of costly signaling are also detected. [ABSTRACT FROM AUTHOR]

This paper reports on results of bathymetric and seismoacoustic studies of the shelf in the western part of Peter the Great Bay. Five flooded coastlines, formed in the Late Pleistocene–Holocene, were revealed on the shelf. It was found that a significant part of the shelf is occupied by a zone of irregular sedimentation. This zone is underlain by an erosion surface buried under sediments of ebb–flood tidal deltas in the areas of active sedimentation and is exposed on the seafloor within the area of active modern erosion. The abrasion and formation of the irregular sedimentation zone on the shelf intensified about 11 500–11 700 years ago. Acoustic anomalies, associated with gas occurrences in sediments and gas plumes in the water column, were recorded on the shelf of the bay. Types of anomalies were classified, and a map of their areal distribution was compiled. It is concluded that the trigger mechanism that provides gas migration into sediments and to the water column is associated with a group of factors: the change of the postglacial sea level and abrasion processes, as well as the meteorological and hydrological regimes. [ABSTRACT FROM AUTHOR]

The paper presents new paleobotanical data in combination with the results of radiocarbon dating obtained from organomineral deposits of the northern shore of Pechevalavato Lake (70°13′22.3″ N, 71°50′57.6″ E) in the Seyakha River basin and characterizing the dynamics of vegetation in the northern part of Central Yamal in the Holocene. It has been shown that a tree birch (Betula sect. Betula) grew in Yamal in the early Holocene (10.2–8.7 cal kyr BP) no less than 400 km north of the modern northern limit of distribution of Betula pubescens ssp. tortuosa. Favorable conditions for the existence of birch woodlands at this time were provided by a higher temperature of the growing season, exceeding the modern parameters of the warmest month of the summer season by approximately 3–4°C. At the end of the early Holocene (after 8.5 cal kyr BP), forest vegetation began to degrade, and open landscapes with diverse plant communities of the subarctic tundra and single trees in the river valley spread. About 6.5 cal kyr BP, the northern subarctic tundra began to form the zonal appearance of the study area in climatic conditions close to modern ones. [ABSTRACT FROM AUTHOR]

Even over relatively recent epochs, galaxies have evolved significantly in their location in the mass–metallicity plane, which must be telling us something about the latter stages of galaxy evolution. In this paper, we analyse data from the LEGA-C survey using semi-analytic spectral and photometric fitting to determine these galaxies' evolution up to their observed epoch at z ∼ 0.7. We confirm that, at z ∼ 0.7, many objects already lie on the present-day mass–metallicity relation, but with a significant tail of high-mass low-metallicity galaxies that is not seen in the nearby Universe. Similar modelling of the evolution of galaxies in the nearby MaNGA survey allows us to reconstruct their properties at z ∼ 0.7. Once selection criteria similar to those of LEGA-C are applied, we reassuringly find that the MaNGA galaxies populate the mass–metallicity plane in the same way at z ∼ 0.7. Matching the LEGA-C sample to their mass–metallicity 'twins' in MaNGA at this redshift, we can explore the likely subsequent evolution of individual LEGA-C galaxies. Galaxies already on the present-day mass–metallicity relation form few more stars and their discs fade, so they become smaller and more bulge-like. By contrast, the high-mass low-metallicity galaxies grow their discs through late star formation, and evolve rapidly to higher metallicities due to a cut-off in their wind-driven mass-loss. There are significant indications that this late cut-off is associated with the belated end of strong active galactic nucleus activity in these objects. [ABSTRACT FROM AUTHOR]

The paper considers Sr, Nd, and Pb isotope data obtained for two cores of bottom sediments taken in the Oga and Tsivolki bays of Severny Island of the Novaya Zemlya archipelago. The studied sequence of sediments from Oga Bay has accumulated over the last thousand years. The 87Sr/86Sr ratio decreases from top to bottom down the section from 0.72225 to 0.71995, the value of εNd varies from –6.1 to –5.5. The Pb isotopic composition varies within narrow limits: the 206Pb/204Pb ratio from 19.107 to 19.139, the 207Pb/204Pb ratio from 15.632 to 15.635, and the 208Pb/204Pb ratio from 38.568 to 38.635. A rapid decrease in the 87Sr/86Sr ratio at a relatively stable neodymium and lead isotope composition indicates a change in the source of the clastic material. This can be explained by the fact that the material of the destruction of Permian clay shales, and then Devonian–Silurian sedimentary carbonates, first entered the area of glacier abrasion and further, respectively, into the sedimentation zone. The sediment column from Tsivolki Bay was formed over a little more than 10 000 years. Based on the Sr, Nd, and Pb isotope ratios, these bottom sediments are divided into lower and upper parts: before and after 150 cm (or ~3500 years). In the lower part of the column, the 87Sr/86Sr ratio increases from 0.72055 to 0.72580, the value of εNd remains approximately the same and varies around –8.2. In the upper part, the 87Sr/86Sr ratio drops to 0.72049 in the near-surface layer; at the same time, the value of εNd increases to –6.4. At the boundary of these two units, the 206Pb/204Pb ratio abruptly changes from about 18.0 in the lower part to 19.3 in the upper part and 208Pb/204Pb from about 36.5 in the lower part to 38.7 in the upper part of the section. The change in the Sr, Nd, and Pb isotope characteristics is likely a reflection of changes in the composition of the rocks in the area where the basin was removed, which is now being eroded by the glacier. Comparison with modern sources supplying clastic material to the Kara Sea showed that the material is supplied to the Oga and Tsivolki bays only from Novaya Zemlya. [ABSTRACT FROM AUTHOR]