Decoupling of modern shortening rates, climate, and topography in the Caucasus

Adam M. Forte, Kelin Whipple, Bodo Bookhagen, Matthew W. Rossi

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

The Greater and Lesser Caucasus mountains and their associated foreland basins contain similar rock types, experience a similar two-fold, along-strike variation in mean annual precipitation, and were affected by extreme base-level drops of the neighboring Caspian Sea. However, the two Caucasus ranges are characterized by decidedly different tectonic regimes and rates of deformation that are subject to moderate (less than an order of magnitude) gradients in climate, and thus allow for a unique opportunity to isolate the effects of climate and tectonics in the evolution of topography within active orogens. There is an apparent disconnect between modern climate, shortening rates, and topography of both the Greater Caucasus and Lesser Caucasus which exhibit remarkably similar topography along-strike despite the gradients in forcing. By combining multiple datasets, we examine plausible causes for this disconnect by presenting a detailed analysis of the topography of both ranges utilizing established relationships between catchment-mean erosion rates and topography (local relief, hillslope gradients, and channel steepness) and combining it with a synthesis of previously published low-temperature thermochronologic data. Modern climate of the Caucasus region is assessed through an analysis of remotely-sensed data (TRMM and MODIS) and historical streamflow data. Because along-strike variation in either erosional efficiency or thickness of accreted material fail to explain our observations, we suggest that the topography of both the western Lesser and Greater Caucasus are partially supported by different geodynamic forces. In the western Lesser Caucasus, high relief portions of the landscape likely reflect uplift related to ongoing mantle lithosphere delamination beneath the neighboring East Anatolian Plateau. In the Greater Caucasus, maintenance of high topography in the western portion of the range despite extremely low (

Original languageEnglish (US)
Pages (from-to)282-294
Number of pages13
JournalEarth and Planetary Science Letters
Volume449
DOIs
StatePublished - Sep 1 2016

Fingerprint

decoupling
Topography
climate
topography
Tectonics
gradients
Caucasus Mountains (U.S.S.R.)
tectonics
relief
Geodynamics
MODIS (radiometry)
delamination
geodynamics
TRMM
foreland basin
rate
erosion rate
hillslope
Delamination
lithosphere

Keywords

  • climate
  • dynamic topography
  • erosion
  • orogenic processes
  • tectonics

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science

Cite this

Decoupling of modern shortening rates, climate, and topography in the Caucasus. / Forte, Adam M.; Whipple, Kelin; Bookhagen, Bodo; Rossi, Matthew W.

In: Earth and Planetary Science Letters, Vol. 449, 01.09.2016, p. 282-294.

Research output: Contribution to journalArticle

Forte, Adam M. ; Whipple, Kelin ; Bookhagen, Bodo ; Rossi, Matthew W. / Decoupling of modern shortening rates, climate, and topography in the Caucasus. In: Earth and Planetary Science Letters. 2016 ; Vol. 449. pp. 282-294.
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