Sedimentary records of lipid biomarkers such as leaf wax n-alkanes are not only influenced by ecosystem turnover and physiological changes in plants, they are also influenced by earth surface processes integrating these signals. The integration of biomarkers into the sedimentary record and the effects of integration processes on recorded environmental signals are complex and not fully understood. To determine the depositional constraints on biomarker records in a high-altitude small catchment system, we collected both soil and stream sediments along a 1000 m altitude transect (1500 – 2500 masl) in the Areguni Mountains, a subrange of the Lesser Caucasus Mountains in Armenia. We utilize the existence of a treeline at ~ 2000 masl, which separates alpine meadow above from deciduous forest below, to assess the relative contribution of upstream biomarker transport to local vegetation input in the stream. We find that average chain length (ACL), hydrogen isotope (δD) and carbon isotope (δ¹³C) values of n-alkanes are significantly different in soils collected above and below the treeline. However, samples collected from the stream sediments do not integrate these signals quantitively. As the stream drops below the treeline, the ACL, δD and δ¹³C values of n-alkanes preserved in streambed sediments reflect a bias toward n-alkanes sourced from trees. This suggests that there is either 1) minimal transportation of organic matter from the more open vegetation in higher elevations, or 2) greater production of target biomarkers by trees and shurbs found at lower elevations results in overprinting of stream signals by local vegetation. Though this latter observation may preclude using n-alkanes to measure past treeline movement in these mountains, δD values of biomarkers in fluvial deposits in these settings are more likely to record local hydrological changes rather than changes in upstream fractionation differences associated with vegetation turnover.

This paper introduces the results from our excavations of the open-air late Upper Paleolithic site of Kalavan 6, Armenia. The site is embedded in a sedimentological sequence spanning from the Last Glacial Maximum (LGM; 26.5–19/20 ka) to the Holocene (i.e., from MIS 2 to 1). Our findings are presented together with chronological, environmental, and climatic data. Luminescence dating provides a temporal framework for reoccupation of the Armenian Highlands after the LGM, while two vegetation proxies (pollen assemblages and leaf waxes) characterize the environment. Based on these pollen data, a quantitative climate reconstruction (temperatures and precipitation) is offered. Techno-typological characterization of the lithic assemblages is presented together with the sourcing of the entire obsidian assemblage by portable X-ray fluorescence, providing insights into the occupants’ exploited territories. Such a framework, which incorporates both environmental reconstruction and hunter-gatherer behaviors, enables us to contextualize possible links between population dynamics during the height of the LGM and post-LGM environmental oscillations. We suggest that, during the LGM between ca. 24 and 19 ka, the combination of declining temperatures and the extension of the winter season limited the occupation feasibility of the region. The regional occupation resumed when environmental circumstances ameliorated. These results support our interpretation that temperatures and the duration of the seasons conditioned the past hunter-gatherer's occupation of the region.

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 post-depositional 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 spatial variability of MIS 3 environments and its on hominin land use adaptations. This demonstrates the importance of the Armenian Highlands for understanding regional MP settlement dynamics during a critical period of hominin dispersals and evolution.