Unravelling the Holocene climate patterns in North-western India: Insights from lake sediment records

Sediment archives in different climatic zones respond variedly to changing climatic conditions. Hyper-arid climatic zones, known for their extreme temperatures and precipitation, have complex interactions due to changing climatic conditions. The study investigated a shallow core of 5 m from a lacustrine environment in the marginal part of the Little Rann of Kachchh, Kachchh, Western India. The hyper-arid climate and active tectonism make the site crucial for reconstructing changes in the Holocene epoch, which is known to have experienced rapid climatic shifts affecting ancient human settlers. The core has been subjected to a multiproxy (grain size analysis, elemental geochemistry, environmental magnetism, organic carbon, palynology, and chronology) assessment for the three periods of varying environmental conditions during Greenlandian (similar to 11-8.2 ka), Northgrippian (similar to 8.2-4.2 ka), and Meghalayan (similar to 4.2-2 ka) stages of the Holocene epoch. The Early Holocene sediments suggest arid conditions with high-energy depositional environments and weak monsoons, transitioning to fluctuating monsoonal activity by the Middle Holocene. The Mid-Holocene Climatic Optimum (similar to 6-5 ka) marks a peak in monsoonal intensity, with heightened chemical weathering and organic productivity. In contrast, the Late Holocene is characterized by reduced hydrological variability and episodic climatic perturbations, including the 4.2 ka arid event. The climatic conditions during the prominent short-lived arid episode (8.2 ka) exhibit contrasting anomalies, revealing intriguing environmental patterns in the region due to the lack of response by the hyper-arid landscape. These findings provide valuable insights into the unique behavior of hyper-arid regions and their relevance to broader regional climatic reconstructions, with caution.