Denudation and deformation in a glaciated orogenic wedge: The St. Elias orogen, Alaska

Abstract

Research Article| July 01, 2008 Denudation and deformation in a glaciated orogenic wedge: The St. Elias orogen, Alaska Aaron L. Berger; Aaron L. Berger 1Department of Geosciences, 4044 Derring Hall, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA Search for other works by this author on: GSW Google Scholar James A. Spotila James A. Spotila * 1Department of Geosciences, 4044 Derring Hall, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA * E-mail:spotila@vt.edu. Search for other works by this author on: GSW Google Scholar Author and Article Information Aaron L. Berger 1Department of Geosciences, 4044 Derring Hall, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA James A. Spotila * 1Department of Geosciences, 4044 Derring Hall, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA * E-mail:spotila@vt.edu. Publisher: Geological Society of America Received: 03 Dec 2007 Revision Received: 20 Feb 2008 Accepted: 04 Mar 2008 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2008 Geological Society of America Geology (2008) 36 (7): 523–526. https://doi.org/10.1130/G24883A.1 Article history Received: 03 Dec 2007 Revision Received: 20 Feb 2008 Accepted: 04 Mar 2008 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Aaron L. Berger, James A. Spotila; Denudation and deformation in a glaciated orogenic wedge: The St. Elias orogen, Alaska. Geology 2008;; 36 (7): 523–526. doi: https://doi.org/10.1130/G24883A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Apatite (U-Th)/He dating from the St. Elias orogen in southern Alaska illustrates a potential association between long-term denudation and glacier sliding. Cooling ages as young as 0.4 Ma (exhumation ~4–5 mm/yr) are concentrated in a narrow band near the glacier equilibrium line altitude (ELA) front, where mean Quaternary ELA intersects the windward flank of the orogen. This band of denudation is not correlated with individual faults, structural trends, or known concentrations of precipitation, and we propose that it is produced by focused glacier sliding at or near the ELA front. This implies that long-term glacial erosion is a maximum at ELA, which corroborates model predictions that glaciers and climate can control the pattern of crust removal from orogens. Denudation rates do not covary with fluctuations in glacier size along the ELA front, suggesting that small glaciers are capable of keeping pace with incision by larger ones and tectonic rock uplift. Ice discharge may thus play a critical, but complex, role in excavating glaciated orogens. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.