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Title: Middle and Late Pleistocene glaciations in the southwestern Pamir and their effects on topography [Topography of the SW Pamir shaped by middle-late Pleistocene glaciation]

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 source113 ± 10ka, 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. As a result, localized rapid fluvial incision and drainage network reorganization reflect the transient nature ofmore » the deglaciated landscape.« less

Authors:
ORCiD logo [1];  [1];  [2];  [1];  [3];  [4];  [1]
  1. Eberhard Karls Univ. Tubingen, Tubingen (Germany)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  3. U.S. Geological Survey, Golden, CO (United States)
  4. Technische Univ. Bergakademie Freiberg, Freiberg (Germany)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1351141
Alternate Identifier(s):
OSTI ID: 1396588
Report Number(s):
LLNL-JRNL-700769
Journal ID: ISSN 0012-821X; TRN: US1700577
Grant/Contract Number:
AC52-07NA27344
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Earth and Planetary Science Letters
Additional Journal Information:
Journal Volume: 466; Journal Issue: C; Journal ID: ISSN 0012-821X
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; Pamir; Central Asia; cosmogenic nuclide dating; Pleistocene; glacial chronology; geomorphology

Citation Formats

Stübner, Konstanze, Grin, Elena, Hidy, Alan J., Schaller, Mirjam, Gold, Ryan D., Ratschbacher, Lothar, and Ehlers, Todd. Middle and Late Pleistocene glaciations in the southwestern Pamir and their effects on topography [Topography of the SW Pamir shaped by middle-late Pleistocene glaciation]. United States: N. p., 2017. Web. doi:10.1016/j.epsl.2017.03.012.
Stübner, Konstanze, Grin, Elena, Hidy, Alan J., Schaller, Mirjam, Gold, Ryan D., Ratschbacher, Lothar, & Ehlers, Todd. Middle and Late Pleistocene glaciations in the southwestern Pamir and their effects on topography [Topography of the SW Pamir shaped by middle-late Pleistocene glaciation]. United States. doi:10.1016/j.epsl.2017.03.012.
Stübner, Konstanze, Grin, Elena, Hidy, Alan J., Schaller, Mirjam, Gold, Ryan D., Ratschbacher, Lothar, and Ehlers, Todd. Mon . "Middle and Late Pleistocene glaciations in the southwestern Pamir and their effects on topography [Topography of the SW Pamir shaped by middle-late Pleistocene glaciation]". United States. doi:10.1016/j.epsl.2017.03.012. https://www.osti.gov/servlets/purl/1351141.
@article{osti_1351141,
title = {Middle and Late Pleistocene glaciations in the southwestern Pamir and their effects on topography [Topography of the SW Pamir shaped by middle-late Pleistocene glaciation]},
author = {Stübner, Konstanze and Grin, Elena and Hidy, Alan J. and Schaller, Mirjam and Gold, Ryan D. and Ratschbacher, Lothar and Ehlers, Todd},
abstractNote = {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 source113 ± 10ka, 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. As a result, localized rapid fluvial incision and drainage network reorganization reflect the transient nature of the deglaciated landscape.},
doi = {10.1016/j.epsl.2017.03.012},
journal = {Earth and Planetary Science Letters},
number = C,
volume = 466,
place = {United States},
year = {Mon Mar 27 00:00:00 EDT 2017},
month = {Mon Mar 27 00:00:00 EDT 2017}
}

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