Palaeoshorelines of glacial Lake Kuray–Chuja, south-central Siberia: form, sediments and process

Abstract

Abstract Glacial lake Kuray–Chuja which occupied the Kuray and Chuja Basins during the Quaternary Period (Marine Isotope Stages 2 and 3) left distinct shoreline features around the basin margins. At the greatest extent the lake had a surface area of 2951 km 2 with wind fetches up to 70 km. Wind waves constructed erosional, erosional-accumulative and accumulative strandlines, the latter including spits, tombolos, barrier beaches and offshore bars. Strandlines range in altitude between c . 1600 and 2100 m, the range in altitudes demonstrating lake level variations through time. The shoreline forms and stratigraphy are detailed. Particular attention is given to the presence of pocket beaches on rock-coasts, the alluvial strandlines of which have distinctive alongshore gradients. Although reasonably ascribed to regional differential tectonic uplift, the possibility that the local alongshore gradients are augmented as a process response to alongshore drift of sediment in a sediment-starved system of closed coastal cells is explored using a simple numerical model.