Barozh 12: formation processes of a late Middle Paleolithic open-air site in western Armenia

© 2020 Elsevier Ltd Barozh 12 is a Middle Paleolithic (MP) open-air site located near the Mt Arteni volcanic complex at the margins of the Ararat Depression, an intermontane basin that contains the Araxes River. Sedimentology, micromorphology, geochronology, biomarker evidence, together with an assessment of artifact taphonomy permits the modelling of site formation processes and paleoenvironment at a level of detail not previously achieved in this area. Obsidian MP artifacts were recovered in high densities at Barozh 12 from four stratigraphic units deposited during marine oxygen isotope stage 3 (MIS 3) (60.2 ± 5.7–31.3 ± 3 ka). The MIS 3 sequence commences with low energy alluvial deposits that have been altered by incipient soil formation, while artifact assemblages in these strata were only minimally reworked. After a depositional hiatus, further low energy alluvial sedimentation and weak soil formation occurred, followed by higher energy colluvial (re)deposition and then deflation. Artifacts in these last stratigraphic units were more significantly reworked than those below. Analysis of plant leaf wax (n-alkane) biomarkers shows fluctuating humidity throughout the sequence. Collectively the evidence suggests that hunter-gatherers equipped with MP lithic technology repeatedly occupied this site during variable aridity regimes, demonstrating their successful adaptation to the changing environments of MIS 3

Human occupation of northern Europe in MIS 13: Happisburgh Site 1 (Norfolk, UK) and its European context

The timing, environmental setting and archaeological signatures of an early human presence in northernEurope have been longstanding themes of Palaeolithic research. In the space of 20 years, the earliestrecord of human occupation in Britain has been pushed back from 500 ka (Boxgrove) to 700 ka (Pakefield)and then to >800 ka (Happisburgh Site 3). Other sites also contribute to this record of humanoccupation; a second locality at Happisburgh, referred to as Site 1, attests to human presence at around500 ka (MIS 13). This paper provides the first comprehensive account of research undertaken at HappisburghSite 1 since 2000. The early human landscape and depositional environment was that of a riverfloodplain, where an active river channel, in which a grey sand was deposited, was abandoned, forming afloodplain lake, with marginal marsh/swamp environments, which was infilled with organic mud. Thissuccession is sealed by Middle Pleistocene glacial deposits. An assemblage of 199 flint flakes, flake toolsand cores was recovered from the grey sand and organic mud. The evidence from Happisburgh Site 1 isplaced in the context of the wider British and European MIS 13 record. The growing evidence for asignificant dispersal of humans into northern Europe around 500 ka raises critical questions concerningthe environmental conditions under which this took place. We also consider the evolutionary andbehavioural changes in human populations that might have enabled the more widespread and persistentperiod of human presence in northern Europe at this time.</p

Palaeoenvironmental and chronological context of hominin occupations of the Armenian Highlands during MIS 3:Evidence from Ararat-1 cave

Archaeological and palaeoenvironmental evidence from the Armenian Highlands and wider southern Caucasus region emphasises the significance of Marine Oxygen Isotope Stage 3 (c. 57–29 ka) as a crucial period for understanding hominin behaviours amidst environmental fluctuations. Ararat-1 cave, situated in the Ararat Depression, Republic of Armenia, presents potential for resolving emerging key debates regarding hominin land use adaptations during this interval, due to its well-preserved lithic artefacts and faunal assemblages. We present the first results of combined sedimentological, geochronological (luminescence and radiocarbon), archaeological and palaeoecological (macrofauna, microfauna and microcharcoal) study of the Ararat-1 sequence. We demonstrate sediment accumulation occurred between 52 and 35 ka and was caused by a combination of aeolian activity, cave rockfall and water action. Whilst the upper strata of the Ararat-1 sequence experienced postdepositional disturbance due to faunal and anthropogenic processes, the lower strata remain relatively undisturbed. We suggest that during a stable period within MIS 3, Ararat-1 was inhabited by Middle Palaeolithic hominins amidst a mosaic of semi-arid shrub, grassland, and temperate woodland ecosystems. These hominins utilised local and distant toolstone raw materials, indicating their ability to adapt to diverse ecological and elevation gradients. Through comparison of Ararat-1 with other sequences in the region, we highlight the spatia

Short-term occupations at high elevation during the Middle Paleolithic at Kalavan 2 (Republic of Armenia)

The Armenian highlands encompasses rugged and environmentally diverse landscapes and is characterized by a mosaic of distinct ecological niches and large temperature gradients. Strong seasonal fluctuations in resource availability along topographic gradients likely prompted Pleistocene hominin groups to adapt by adjusting their mobility strategies. However, the role that elevated landscapes played in hunter-gatherer settlement systems during the Late Pleistocene (Middle Palaeolithic [MP]) remains poorly understood. At 1640 m above sea level, the MP site of Kalavan 2 (Armenia) is ideally positioned for testing hypotheses involving elevation-dependent seasonal mobility and subsistence strategies. Renewed excavations at Kalavan 2 exposed three main occupation horizons and ten additional low densities lithic and faunal assemblages. The results provide a new chronological, stratigraphical, and paleoenvironmental framework for hominin behaviors between ca. 60 to 45 ka. The evidence presented suggests that the stratified occupations at Kalavan 2 locale were repeated ephemerally most likely related to hunting in a high-elevation within the mountainous steppe landscape.info:eu-repo/semantics/publishedVersio

Pleistocene environments, climate, and human activity in Britain during Marine Isotope Stage 7: insights from Oak Tree Fields, Cerney Wick, Gloucestershire

Investigations at Oak Tree Fields, Cerney Wick, Gloucestershire, in western England have revealed a sequence of fluvial deposits dating from Marine Oxygen Isotope Stage (MIS) 7 to 5. At the base of the sequence, a series of gravel and sand facies were deposited, initially as part of a meandering river. Reductions in flow energy of the latter and avulsion led to the development of short-lived channels and episodic backwater environments, the deposits of which are recorded as Facies Associations 1–3. Poorly sorted, probably colluvial deposits formed beyond the limit of the channel (Facies Association 4). Mollusca, Coleoptera, plant macrofossils, pollen and vertebrates recovered from the channel facies indicate broadly similar climatic conditions throughout accretion. Temperature ranges derived from mutual climatic range analysis of the Coleoptera almost completely overlap with those of Cerney Wick at the present day, albeit that winters may have been cooler when the channel was active. Further, the floral and faunal data suggest that the meandering river flowed through an open grassland environment, the latter heavily grazed by large vertebrates, most notably mammoth. Most of the botanical and faunal remains, together with four optically stimulated luminescence (OSL) age estimates ranging from 225 ± 23 to 187 ± 19 ka, suggest correlation of the channel deposits with MIS 7. The basal deposits (Facies Association 1) yielded the majority of vertebrate remains and all the lithic artefacts, most of which seem likely to have travelled only a short distance. Although only a few artefacts were recovered, they add to the relatively limited evidence of human activity from the upper Thames. The channel deposits are overlain by sheet gravels (Facies Association 5) which are attributed to the Northmoor Member of the Upper Thames Formation. These were likely to have been deposited as bedload in a braided stream environment, while two OSL age estimates of 129 ± 14 and 112 ± 11 ka suggest accumulation during MIS 5

Ancient DNA reveals interstadials as a driver of common vole population dynamics during the last glacial period

Aim Many species experienced population turnover and local extinction during the Late Pleistocene. In the case of megafauna, it remains challenging to disentangle climate change and the activities of Palaeolithic hunter-gatherers as the main cause. In contrast, the impact of humans on rodent populations is likely to be negligible. This study investigated which climatic and/or environmental factors affect the population dynamics of the common vole. This temperate rodent is widespread across Europe and was one of the most abundant small mammal species throughout the Late Pleistocene. Location Europe. Taxon Common vole (Microtus arvalis). Methods We generated a dataset comprised of 4.2 kb long fragment of mitochondrial DNA (mtDNA) from 148 ancient and 51 modern specimens sampled from multiple localities across Europe and covering the last 60 thousand years (ka). We used Bayesian inference to reconstruct their phylogenetic relationships and to estimate the age of the specimens that were not directly dated. Results We estimated the time to the most recent common ancestor of all last glacial and extant common vole lineages to be 90 ka ago and the divergence of the main mtDNA lineages present in extant populations to between 55 and 40 ka ago, which is earlier than most previous estimates. We detected several lineage turnovers in Europe during the period of high climate variability at the end of Marine Isotope Stage 3 (MIS 3; 57-29 ka ago) in addition to those found previously around the Pleistocene/Holocene transition. In contrast, data from the Western Carpathians suggest continuity throughout the Last Glacial Maximum (LGM) even at high latitudes. Main Conclusions The main factor affecting the common vole populations during the last glacial period was the decrease in open habitat during the interstadials, whereas climate deterioration during the LGM had little impact on population dynamics. This suggests that the rapid environmental change rather than other factors was the major force shaping the histories of the Late Pleistocene faunas.info:eu-repo/semantics/publishedVersio

Population dynamics and demographic history of Eurasian collared lemmings.

BACKGROUND: Ancient DNA studies suggest that Late Pleistocene climatic changes had a significant effect on population dynamics in Arctic species. The Eurasian collared lemming (Dicrostonyx torquatus) is a keystone species in the Arctic ecosystem. Earlier studies have indicated that past climatic fluctuations were important drivers of past population dynamics in this species. RESULTS: Here, we analysed 59 ancient and 54 modern mitogenomes from across Eurasia, along with one modern nuclear genome. Our results suggest population growth and genetic diversification during the early Late Pleistocene, implying that collared lemmings may have experienced a genetic bottleneck during the warm Eemian interglacial. Furthermore, we find multiple temporally structured mitogenome clades during the Late Pleistocene, consistent with earlier results suggesting a dynamic late glacial population history. Finally, we identify a population in northeastern Siberia that maintained genetic diversity and a constant population size at the end of the Pleistocene, suggesting suitable conditions for collared lemmings in this region during the increasing temperatures associated with the onset of the Holocene. CONCLUSIONS: This study highlights an influence of past warming, in particular the Eemian interglacial, on the evolutionary history of the collared lemming, along with spatiotemporal population structuring throughout the Late Pleistocene