An Early-Mid Holocene process of regional desertification recorded in aeolian sediments from the northern slope of the middle Himalayan Mountains
Abstract. Aeolian sediments, a sensitive paleoclimatic and paleoenvironmental archive, are widely distributed over the Tibetan Plateau. In the northern slope of the Himalayan Mountains, however, the potential linkages between the aeolian processes, climatic changes, and the processes of desertification during the Holocene are not well understood. Here, we use an aeolian record from the northern slope of the middle Himalayan Mountains to investigate the influences of paleoclimate and paleoenvironment during the Early-Mid Holocene through the optically stimulated luminescence (OSL) dating, magnetic parameters, color variations, scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), and grain size parameters. Glacial sediments, weathering products, the surface of lack of vegetation cover, and alluvium and ancient lacustrine sediments had provided the sources for the aeolian sediments. The strengthened Indian monsoon intensity, dry and warm climate, and sparse vegetation cover accelerated the rapid expansion of desertification between ~11 and 9.6 ka B.P.. The Indian monsoon intensity weakened between 9.6 and 6.3 ka B.P., the warm and humid climate and increased vegetation cover decelerated the rapid expansion of desertification. Influenced by the weakened Indian monsoon intensity, warm and humid climate, increased vegetation cover, and limited sources, the desertification decelerated further between 6.3 and ~4.5 ka B.P.. Further, the linkage and interplay between changes in the Indian monsoon, vegetation cover, sources, and landforms play a key role in aeolian processes and regional processes of desertification in the northern slope Himalayan Mountains during the Early-Mid Holocene.
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