Post–Little Ice Age record of coarse and fine clastic sedimentation in an Alaskan proglacial lake

Research Article| December 01, 2004 Post–Little Ice Age record of coarse and fine clastic sedimentation in an Alaskan proglacial lake Michael G. Loso; Michael G. Loso 1 Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar Robert S. Anderson; Robert S. Anderson 1 Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar Suzanne P. Anderson Suzanne P. Anderson 1 Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Michael G. Loso 1 Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA Robert S. Anderson 1 Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA Suzanne P. Anderson 1 Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA Publisher: Geological Society of America Received: 18 May 2004 Revision Received: 31 Aug 2004 Accepted: 05 Sep 2004 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2004) 32 (12): 1065–1068. https://doi.org/10.1130/G20839.1 Article history Received: 18 May 2004 Revision Received: 31 Aug 2004 Accepted: 05 Sep 2004 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Michael G. Loso, Robert S. Anderson, Suzanne P. Anderson; Post–Little Ice Age record of coarse and fine clastic sedimentation in an Alaskan proglacial lake. Geology 2004;; 32 (12): 1065–1068. doi: https://doi.org/10.1130/G20839.1 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 Many assessments of glacial sediment yield rely solely on measurements of fine-grained suspended sediment. We show that suspended sediment contributes <20% of the total clastic sediment discharge into Iceberg Lake, an Alaskan proglacial lake. Drainage of this lake in 1999 exposed outcrops of varved lacustrine sediment that record suspended sediment deposition. Since a Little Ice Age highstand two centuries ago, lake level has dropped in four abrupt spillway-controlled events that are recorded stratigraphically as transient increases in the basinwide deposition of unusually fine grained sediments. Varve counting constrains ages of these events and, hence, of each abandoned shoreline and associated delta. Volumes of deltaic and lake-floor sediments constrain specific yields from four multidecadal intervals between A.D. 1825 and 1999. Total yield ranges from 3.8 to 4.9 × 103 t·km−2·yr−1, and most of the sediment (81%–86%) is sand and gravel now in the deltas. A range of evidence suggests that sediment yield faithfully records upstream sediment production in this small (66 km2) and heavily glacierized basin, implying an effective subglacial erosion rate of 1.6 mm/yr. These data show that estimates of total yield based upon suspended sediment alone are subject to large errors and suggest that quarrying accounts for a large fraction of the glacial erosion in this system. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.