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Middle and Late Pleistocene glaciations in the southwestern Pamir and their effects on topography

Earth and Planetary Science Letters

By:
, , , , , , and
https://doi.org/10.1016/j.epsl.2017.03.012

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Abstract

Glacial chronologies provide insight into the evolution of paleo-landscapes, paleoclimate, topography, and the erosion processes that shape mountain ranges. In the Pamir of Central Asia, glacial morphologies and deposits indicate extensive past glaciations, whose timing and extent remain poorly constrained. Geomorphic data and 15 new 10Be exposure ages from moraine boulders and roches moutonnées in the southwestern Pamir document multiple Pleistocene glacial stages. The oldest exposure ages, View the MathML source, underestimate the age of the earliest preserved glacial advance and imply that the modern relief of the southwestern Pamir (peaks at ∼5000–6000 m a.s.l.; valleys at ∼2000–3000 m a.s.l.) already existed in the late Middle Pleistocene. Younger exposure ages (∼40–80 ka, ∼30 ka) complement the existing Central Asian glacial chronology and reflect successively less extensive Late Pleistocene glaciations. The topography of the Pamir and the glacial chronologies suggest that, in the Middle Pleistocene, an ice cap or ice field occupied the eastern Pamir high-altitude plateau, whereas westward flowing valley glaciers incised the southwestern Pamir. Since the Late Pleistocene deglaciation, the rivers of the southwestern Pamir adjusted to the glacially shaped landscape. Localized rapid fluvial incision and drainage network reorganization reflect the transient nature of the deglaciated landscape.

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Middle and Late Pleistocene glaciations in the southwestern Pamir and their effects on topography
Series title:
Earth and Planetary Science Letters
DOI:
10.1016/j.epsl.2017.03.012
Volume:
466
Year Published:
2017
Language:
English
Publisher:
Elsevier
Contributing office(s):
Geologic Hazards Science Center
Description:
14 p.
First page:
181
Last page:
194