PALEOGEOGRAPHICAL EVOLUTION AND GEOCHEMICAL CHARACTERISTICS OF THE LOWER ZERAVSHAN BASIN: FLUVIAL DYNAMICS AND PREHISTORIC HUMAN SETTLEMENT

This research presents a comprehensive paleogeographical and geochemical analysis of the Zeravshan River basin in connection with the geomorphological evolutionary phases of the Kyzylkum Desert during the Quaternary and Holocene epochs. The study critically evaluates the hydrological transitions that occurred during the late Neolithic, Eneolithic, and Bronze Ages, demonstrating how localized river breakthroughs formed dynamic, interconnected lacustrine environments—structurally analogous to Venice—across the hyper-arid matrix. Utilizing historical empirical data compiled by B.A. Molodtsov and other foundational researchers, a comparative matrix of alluvial silt deposits across Central Asia's three prominent rivers (Zeravshan, Amu Darya, and Syr Darya) was analyzed. The mineralogical breakdown reveals that while the Amu Darya holds quantitative superiority in lime content (CaO), the Zeravshan River exhibits an explicit geochemical predominance in silica (SiO₂ at 52.40%), sesquioxides, phosphorus, magnesium, and potassium. Furthermore, the paper establishes a direct correlation between these high-yield chemical configurations and the localization of prehistoric human adaptation sites, such as the Sazagan complexes, situated at elevations of 800–1100 meters within the Karatepa mountain massif. By synthesizing localized climatic shifts like the "Lyavlyakan Moisture" phenomenon with micro-faunal and floral successions (reedbeds, wild boar, deer, and lacustrine biomes), this study provides a critical framework for understanding long-term environmental sustainability and prehistoric anthropogenic trajectories in the Central Asian river oases. Keywords: Zeravshan River, Paleogeography, Fluvial Dynamics, Silt Geochemistry, Kyzylkum Desert, Neolithic Settlement, Lyavlyakan Moisture, Holocene Hydrology