Micromorphology of quartz grain surface as indicator of glacial sedimentation conditions: Evidence from the Protva River Basin

Micromorphology of quartz grain surface was studied with the use of scanning electron microscopy in order to specify sedimentation environment in the Protva River Basin in the central Russian Plain. Quartz grains from medium sand fraction (0.25-0.5 mm) taken from 27 samples of Early Pleistocene alluvial sediments and Middle Pleistocene glacial, fluvioglacial, and lacustrine sediments were examined. It was established that the studied sediments contain three major types of quartz grains with (1) glacial, (2) hydrodynamic, and (3) eolian features of transport. Sediments of these genetic types differ by ratios of grains of the micromorphological types. Relationships between eluvial (frost-glacial), hydrodynamic, and eolian components regularly change with variations in climatic conditions. The portion of fluvial component increases in warm conditions, whereas increase of eolian component is typical of cold conditions. The data obtained suggest that the study of morpholithogenesis in glaciation environment should take into consideration not only terrigenous provenances, but also terrigenous agents, i.e., groups of processes responsible for the transport of particles.