COLLABORATIVE RESEARCH: Relief Evolution at the Fluvial-Glacial Transition

Purdue Research Foundation, West Lafayette IN

Investigators

Abstract

9980419 Granger Most mid- and high-latitude mountain ranges have been sculpted dramatically by glacial erosion. The isolated spires, narrow ridges, long bare-rock hillslopes, and broad valleys of alpine terrain immediately give a qualitative impression that glaciers are highly efficient erosive agents and that glacial erosion produces considerable relief. However, little is known quantitatively about the rates and patterns of glacial erosion, the factors that control them, nor even the morphological consequences of a shift from fluvial (non-glacial) to glacial erosion. We propose to exploit natural laboratories at the southern limit of glaciation where adjacent fully-, partially-, and un-glaciated, but otherwise similar, basins can be studied. We identify two field settings in the eastern Sierra Nevada, California, and the northern Sangre de Cristo range, Colorado, where one may estimate quantitatively the amount and pattern of topographic change attributable to glacial erosion alone as a function of the intensity of glaciation. We propose a research program in these two field settings combining field mapping, DEM analysis, and cosmogenic isotope dating to test quantitatively 5 hypotheses developed during a preliminary investigation of glacial landforms and erosion