Morphometric Analysis of Pleistocene Glacial Deposits in the Kigluaik Mountains, Northwestern Alaska, U.S.A.

Abstract

Since the earliest studies of alpine glacial geology, descriptive evaluation of moraine morphology has remained an important relative-age criterion. However, the development of moraine morphology as a quantitative relative-dating tool has lagged considerably behind other techniques. Morphometric and other relative-age data were collected on early- to late-Pleistocene end moraines located in the Kigluaik Mountains of Seward Peninsula, Alaska. Slope-frequency, Fourier, and linear regression analyses of toporgraphic profiles measured along and normal to moraine axial-crests were used to generate nine indices of surface irregularity. Discriminant analysis indicates that average slope, calculated from the slope-frequency distribution, is the best single distinguishing criterion, and that even a few simple field measurements of morphometry provide a viable basis for subdividing and correlating moraines. Morphometric and other relative-age data constrain the timing of glaciations in the Kigluaik Mountains, and suggest that successively older advances are separated by intervals of increasing duration. In addition, morphometric study of moraines can offer insights into processes controlling landscape degradaion.