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Paleolimnology and Natural Versus Anthropogenic Influx During the Late Holocene from Vembanad Wetland, Ramsar Site, Kerala, India

A multi-proxy study of diatoms, palynofacies, and grain size was conducted on a 100 cm core from Arookutty, Vembanad wetland, Kerala, India, to reconstruct paleolimnological changes during the late Holocene, with a focus on natural versus anthropogenic influences. Four distinct depositional phases, from ca. 500 BCE to ca. 400 CE, were identified, aligning with the Roman Warm Period (RWP). The period from ca. 500 BCE to ca. 450 BCE shows high freshwater and marine planktic diatoms, augmented by silicoflagellates and terrestrial organic matter, with a low dinocyst presence, suggesting a dynamic aquatic environment. The period from ca. 450 BCE to ca. 350 BCE is marked by a high sand content, indicating significant runoff and terrestrial influx, along with increased freshwater and marine planktic diatoms and evidence of human activity in the area. Similarly, the period from ca. 350 BCE to ca. 50 CE is characterized by high sand content and strong anthropogenic influences, with a rise in silicoflagellates, pointing to rising sea levels and high monsoonal precipitation. The period from ca. 50 CE to ca. 400 CE initially shows a decrease in sand and an increase in mud, reflecting a weakening southwest monsoon, likely due to solar variations. However, from ca. 300 CE to ca. 400 CE, sand content rises again, accompanied by high terrestrial influx and dinocysts, while silicoflagellates diminish completely. Thus, despite the dominance of the RWP, the coastal region experienced an extended period of reduced monsoonal activity for a particular span.

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Aeolian Sands of the Temperate Boreal Zone (Northern Asia)

This article is devoted to the study of the Quaternary aeolian sands of the boreal zone of north Asia. Using the example of the study reference sections of the Selenga Dauria (Western Transbaikalia), it was established that the activation of aeolian processes is determined by the complex interaction of natural and anthropogenic factors. Natural factors include neotectonic movements; wide distribution of alluvial and lacustrine-alluvial deposits; a sharply continental semi-arid climate; and forest-steppe and steppe vegetation. Among the anthropogenic factors, the leading ones are deforestation, plowing of land and construction of new settlements, roads and other line structures. The obtained radiocarbon dating of buried soils and coal from ancient fire pits indicates the activation of aeolian processes during the Holocene. The main sources for aeolian transport (winnowing) are sands located in the areas of river and lake beaches, floodplains and river terraces. Almost all aeolian sands of the boreal zone were formed as a result of short-range wind transport. They form mini-deserts unfixed by vegetation, with active aeolian processes, dunes, barkhans and deflationary basins. Aeolian swells and blowout basins characterize aeolian landscapes weakly fixed by vegetation. It is noted that aeolian deposits of the boreal zone of north Asia, in contrast to similar sands of the subtropical and tropic zones, consist of coarser-grained material. Medium- and fine-grained sands dominate their composition, which is polymineral and well-sorted. In subtropical and tropical deserts, they are predominantly monomineral, fine and fine-grained. At the same time, mainly minerals that are unstable to weathering (feldspars, plagioclases, pyroxenes and amphiboles) represent the mineralogical composition of the studied aeolian sands. Weathering-resistant minerals dominate the sands of classical deserts: quartz, leucoxene, ilmenite, epidote, zircon, garnets, tourmaline, rutile and others. Modern aeolian landscapes are a unique natural formation for the boreal zone of north Asia and can be successfully used for the development of ecotourism.

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The Lost MIS 11c Mammalian Fauna from Via dell’Impero (Rome, Italy)

This research presents an in-depth analysis of large mammal remains first discovered in 1932 in the archaeological area of ancient Rome, central Italy, during the work for the opening of Via dell’Impero (VFI). This work describes the faunal assemblage, its current preservation status, and uses tephrochronology to assess its age. Additionally, it provides paleoecological insights into the evolution of the mammalian fauna in Latium, central Italy, from MIS 13 to MIS 7. Analysis of the fossils updates the identification previously proposed by De Angelis d’Ossat, confirming the presence of Palaeoloxodon antiquus, Cervus elaphus, and Bos primigenius. However, in contrast to the previous author, the hippopotamus remains are assigned to Hippopotamus cf. antiquus, and a second deer is identified as Dama sp. Furthermore, gnawing marks on the hippopotamus femur suggest the presence of a middle-sized carnivore. Tephrochronological investigation was conducted on pumice retrieved from the VFI fossiliferous layer and ash extracted from sediments adhering to the fossil surfaces. The major element composition of the glass from all pumice/ash samples shows a strong affinity with the Vico β unit, allowing correlation with the Fucino record and constraining the deposition of the VFI fossiliferous level between <406.5 ± 1.3 ka and >405.7 + 1.5/−1.6 ka. Radiometric dating is particularly useful for large mammal faunas of MIS 11-MIS 7, a period lacking significant faunal renewals, as Latium mammalian faunas are often dominated by species (elephants, red deer, aurochs) with broad chronological ranges.

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