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THE ROLE OF LAKES IN MORAINE FORMATION, CHILEAN LAKE DISTRICT

1996; Wiley; Volume: 21; Issue: 6 Linguagem: Inglês

10.1002/(sici)1096-9837(199606)21

1096-9837

Michael J. Bentley,

Cryospheric studies and observations

Earth Surface Processes and LandformsVolume 21, Issue 6 p. 493-507 Research Article THE ROLE OF LAKES IN MORAINE FORMATION, CHILEAN LAKE DISTRICT MIKE BENTLEY, Corresponding Author MIKE BENTLEY Department of Geography, University of Edinburgh, Drummond Street, Edinburgh EH8 9XP, U.K.Department of Geography, University of Edinburgh, Drummond Street, Edinburgh EH8 9XP, U.K.Search for more papers by this author MIKE BENTLEY, Corresponding Author MIKE BENTLEY Department of Geography, University of Edinburgh, Drummond Street, Edinburgh EH8 9XP, U.K.Department of Geography, University of Edinburgh, Drummond Street, Edinburgh EH8 9XP, U.K.Search for more papers by this author First published: June 1996 https://doi.org/10.1002/(SICI)1096-9837(199606)21:6 3.0.CO;2-DCitations: 15AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Abstract The nested moraines of the Chilean Lake District have been used to establish a glacial chronology for southernmost South America. This paper focuses on non-climatic controls which may have modulated the climatic signal. It presents a model for formation of the moraines around Lagos Puyehue and Rupanco where there is a nested complex dating from the last glaciation. These moraines can be divided into two types on the basis of their form, position and constituent materials: rampart moraines are broad amalgamated moraine complexes whilst ridge moraines are narrow single ridges usually located around lakeshores. Both types have lateral moraines with low up-glacier longitudinal gradients. Sections in the moraines show they are largely composed of stratified glaciofluvial sediments overthrust on their proximal flanks by clay-rich diamicts containing reworked glaciofluvial material. Despite their different characteristics, a single model explains the features of both moraine types and their location around the down-glacier ends of the lakes. Moraine formation depends crucially on the presence of a layer of water-saturated, fine, impermeable sediment in the lake basins which allows the glacier lobes to advance with negligible surface gradients, probably on a deforming bed. Although the formation of moraines requires a climatically triggered advance, their precise position is not dictated by climatic factors but by contrasts in sediment permeability and grain-size. Citing Literature Volume21, Issue6June 1996Pages 493-507 RelatedInformation