Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
Geology Don't get GSW? Talk to your librarian.
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Geology; December 2004; v. 32; no. 12; p. 1065-1068; DOI: 10.1130/G20839.1
© 2004 Geological Society of America
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Loso, M. G.
Right arrow Articles by Anderson, S. P.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

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

Michael G. Loso*,1, Robert S. Anderson*,1 and Suzanne P. Anderson*,1

1 Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA

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 x 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.

Key Words: glacial erosion • glacial lake • shorelines • sedimentation • Alaska • varves




This article has been cited by other articles:


Home page
 GeologyHome page
T. A. Ehlers, K. A. Farley, M. E. Rusmore, and G. J. Woodsworth
Apatite (U-Th)/He signal of large-magnitude accelerated glacial erosion, southwest British Columbia
Geology, September 1, 2006; 34(9): 765 - 768.
[Abstract] [Full Text] [PDF]

Home page
 Geological Society of America Special PapersHome page
R. S. Anderson, C. A. Riihimaki, E. B. Safran, and K. R. MacGregor
Facing reality: Late Cenozoic evolution of smooth peaks, glacially ornamented valleys, and deep river gorges of Colorado's Front Range
Geological Society of America Special Papers, January 1, 2006; 398(0): 397 - 418.
[Abstract] [Full Text] [PDF]

Home page
 The HoloceneHome page
B. Menounos, J. J. Clague, R. Gilbert, and O. Slaymaker
Environmental reconstruction from a varve network in the southern Coast Mountains, British Columbia, Canada
The Holocene, December 1, 2005; 15(8): 1163 - 1171.
[Abstract] [PDF]


JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Geological Society of America