Abstract:

The loess-paleosol sequences (LPS) of the Kashmir Valley, western Himalaya, comprises a critical yet insufficiently understood archive of late Quaternary climate dynamics, soil alteration and landscape evolution. This study employs a multi-proxy approach to investigate aeolian dynamics, pedogenic alterations, and clay mineral transformations in LPS from key sites—Wanihama, Anchar, Manasbal, Shankarpura, Patan, Choori, Alochibagh, and Burzahama of Kashmir Valley, western Himalaya. Optically Stimulated Luminescence (OSL) dating indicates that the deposits were formed between approximately 300 and 14 ka. Our multiproxy records reveal that clay mineral assemblages in the parent loess of these key deposits are dominated by illite > chlorite > smectite > kaolinite, with chlorite-to-smectite transformations reflecting varied climatic conditions. Pedogenic processes are evidenced by the development of argillic and calcic horizons, classifying the soils as xeric or udic Alfisols. Paleosols, thicker than the loess layers, exhibit multiple pedocomplexes, particularly at Shankarpura, Patan, Manasbal, and Anchar, suggesting intervals of enhanced vegetation cover and soil pedogenesis during ameliorated climate conditions. Further, the presence of N₂-type CaCO₃ nodules, corroborated by δ¹³C and δ¹⁸Oisotopic data, indicates episodic leaching and carbonate reprecipitation, linked to changes in pedogenic processes. Micromorphological features, such as calcite nodules, iron oxide coatings, and root traces, further point to alternating wet and dry phases, facilitating soil formation under variable climatic regimes. Our findings collectively demonstrate that loess deposition and pedogenesis were concurrent processes, driven by complex sedimentological and climatic interactions since the past 300 ka.