GLACIER FLOW PATTERNS IN KHOTON NUUR VALLEY, BAYAN OLGII, MONGOLIA

The Khoton Nuur valley, located near the highest part of the Altai Mountains of far-western Mongolia, features an exceptional record of mountain glacier activity during and since the last glacial period. Here we present a reconstruction of glacial flow patterns recorded from glacial striae in the Tsagaan-gol valley, a tributary of Khoton Nuur lake, at the headwaters of the Khovd River watershed. We identified and mapped orientations of glacial striae etched into ice-molded bedrock of the Tsagaan-gol valley. These features record patterns of ice-flow at the base of the former ice-age Khoton Nuur glacier. We plotted striae orientations on a glacial geomorphological map. Inferred ice flow directions were inferred from associated erosional landforms, such as chatter-marks and crag-and-tail features. Altogether, striae and other directional indicators from this area illustrate the broader pattern of ice-flow at the base of the former Khoton Nuur glacier, and record the relative influence of various tributary glaciers converging from different ice catchments.

Data reported here provide morphological context for a coordinated effort to develop a ¹⁰Be surface-exposure chronology of glacial landforms of the Khoton Nuur system. In addition, our geologically based ice-flow reconstruction will help to evaluate and improve numerical glaciological models of this ice-age glacier system, and aid refinement of inferred paleoclimatic conditions.