Türkiye Jeoloji Bülteni

Sedimantary Facies Analyses and Depositional Environments of Late Quaternary Moraines in Geyikdağ (Central Taurus Mountains)

Abstract: Glacial andperiglacial features ofLate Quaternary age are observednear Geyikdağ (Centra! Taurus Mountains) inU-shaped valleys located at an altitude of more than 2000 in and surrounded by mountain ranges reaching 2850 in.The Namaras Valley and its tributary Susam Valley are characterized by coarse loose materialforming chaotic knoband-kettle topography covering more than 30 knT. Mounds, 1-10 m high and 10-30 hi wide, are separated by 5-30 mwide, few meters deep, irregular depressions. The uppersurfaces of the mounds are covered by angular to şubatıgularlimestone pebbles and blocks and internal sediments show a typical diamicton appearance with pebbles suspended ina muddy to sandy matrix. These chaotic structures are interpreted as hummocky disintegration morainesfrom form erglaciers. Several morainic ridges, up to 200 m high and more than 500 m long that limit the hummocky moraines areinterpreted as ice-marginal lateral, and terminal moraines. In the tributary Susam Valley, part of the coarse loosematerial forms a tongue-shaped structure with successive arcuate ridges and furrows al its down valley reach. Thisstructure, which is connected upward to a talus slope and perched cirque, ressembles the morphology of a periglacialrock glacier but is interpreted as the disintegration moraine controlled by small periodic retreat and readvance of thelast active, ice-front in this region. The distribution of valley glaciers and sedimentological aspects of the related moraines are poorly known inTurkey. The identification: of different types of moraines and their deposition®! conditions in Geyikdağ providehnportctnt information in the understanding of dynamics, magnitude and timing of Late Quaternary glaciations inTurkey.