Monsoon variability and chemical weathering during the late Pleistocene in the Goriganga basin, higher Central Himalaya, India

Abstract

Stable isotope analysis along with radiocarbon and luminescence dating of late Pleistocene lacustrine deposits at Burfu in the higher central Himalaya are used to interpret hydrologic changes in the lake basin. From 15.5 ka to ~14.5 ka the Burfu lake was largely fed by melting glaciers. A warming event at 14.5 ka suggests an enhanced monsoon and increased carbonate weathering. From ~13.5 ka to ~12.5 ka the isotopic data suggest large-amplitude climate variability. Following this, the isotope data suggest a short-lived, abrupt cooling event, comprising a ~300-yr intense cool period followed by a ~500-yr interval of moderate climate. A shift in isotope values at ~11.3 ka may signify a strengthening monsoon in this region. The inferred climatic excursions appear to be correlative, at least qualitatively, with global climatic events, and perhaps the Burfu lake sequence provides regional evidence of globally recorded excursions. This study also suggests a potential use of radiocarbon ages in specific environments as a paleoenvironmental proxy.