Late Quaternary glacial history of the Panchachuli Glacier, Darma valley, Uttarakhand, Central Himalaya: Insights from geomorphic mapping and OSL Chronology

Abstract

This study reconstructs the late Quaternary glacial history of the Panchachuli (Neola) glacier, Darma Valley in the Central Himalayan region. Detailed geomorphic mapping and Optical Stimulated Luminescence (OSL) dating of the moraines and associated outwash terraces was carried out to determine the timing of glacial advances and subsequent retreat. Three major glacier advances were identified. The oldest, Panchachuli glacier advance (PGA)-1, is tentatively correlated with Marine Isotope stage (mid MIS 3). PGA-2, dated to ∼19.82 ± 2.41 and 20.97 ± 2.36 ka, coincides with the global Last Glacial Maximum (gLGM; MIS 2). PGA-3, dated to ∼5.16 ± 0.46 and 8.72 ± 1.02 ka, aligns with the early to mid-Holocene (mid-MIS 1). To constrain the deglaciation history, OSL dating was applied to fluvial terrace deposits, revealing distinct phases of glacier retreat. The oldest fluvial sediments date (∼31.61 ± 3.61 ka) suggest deglaciation during the late MIS 3, a period marked by elevated solar insolation and enhanced monsoon activity. Subsequent deglaciation phases (∼14–16 ka) correspond with the Bølling-Allerød warming, while the later phase (∼2.6–2.9 ka) reflects glacier recession during the late Holocene glacier recession. The glaciation pattern in the Central Himalayas underscores the combined influence of temperature and precipitation on glacier behavior. These glacier changes align with regional Himalayan patterns, reflecting a coherent response to climatic fluctuations. While advances during mid-MIS 3 and gLGM suggest synchrony with North Atlantic climate events, the early Holocene advances—despite regional warming, mirror MIS 3 trends, highlighting the complex and non-linear interplay between temperature, moisture and glacier dynamics.