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Late Pleistocene climate variability and chemical weathering in the Goriganga, higher central Himalaya, north India

Posted on:2008-01-16Degree:Ph.DType:Dissertation
University:Western Michigan UniversityCandidate:Beukema, Steven PaulFull Text:PDF
GTID:1440390005974341Subject:Geology
Abstract/Summary:
Relict lacustrine deposits in the Higher Central Himalaya, India, provide a rich repository of paleoclimate information for the period 16 ka to 11 ka. Stable isotope analysis of deposits near the village of Burfu shows the hydrologic balance between glacial meltwater and monsoon precipitation as source waters for the lake. During the period from 15.5 ka to 14 ka the Burfu lake was largely fed by melting glaciers. A warming event correlated to glacial Meltwater Pulse 1a indicates a sudden increase in carbonate weathering in the region accompanied by a gradual decrease in the ratio of glacial meltwater/monsoon precipitation feeding the lake. The Bolling-Allerod is characterized by large amplitude variability in oxygen and carbon isotopes. A short-lived, abrupt cooling event, comprising a ∼300 year intense cool period followed by a ∼600 year interval of moderate climate is seen. This is possibly correlated to the Younger Dryas cooling event. Isotope values sharply increase at the onset of the Holocene, likely due to an increase in temperature which results in a strengthening of the monsoon and an increase in chemical weathering.
Keywords/Search Tags:Weathering, Increase
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