Petrography and geology of paleolithic locations in the Northern Aral Sea region and Mugodjary (Kazakhstan)

Use of quartzite rocks of the saksaul formation and its continental analogues as raw materials for the lithic industries called “siliceous”, “drain”, “quartzite” sandstones and siltstones, and “quartzites” in Western Kazakhstan has been known since the Middle Paleolithic up to the Early Iron Age. Their earliest use, in Acheulean, took place exactly in the Northern Aral Sea region and Mugodjary. The Paleolithic sites of the Northern Aral Sea region and Mugodjary are associated with the outcrops of quartzite sandstone of the Paleogene age due to the fact that this rock, in terms of its physical characteristics and shallow occurrence, and sometimes its outcrops to the surface, is the only possible source of raw materials for producing stone tools in the region. Despite the fact that the stone material of the Paleolithic location of the Northern Aral Sea and Mugodjary is rather monotonous within the items, it is still macroscopically different, and petrophysical differences become especially evident during weathering. Considering that the paleoclimatic conditions of the Aral Sea region and Mugodjary since the Cretaceous period were under the influence of Aeolian denudation with a constant predominance of westerly winds (due to the rotation of the Earth), the manifestation of this factor on artifacts, generally should be directly proportional to the time of its impact. It was found that deflations on artifacts were subjected both to the original, weathered cavernous surfaces, on which it is manifested by matting and polishing of detrital quartz grains, and its own chipped surfaces forming the artifact. However, it was established that very often, different degrees of deflation are manifested on the same artifact, and not only on the surfaces from different sides of the artifact, but sometimes within the same chipped surface. It means that the weathering degree, including the deflation degree, of quartz sandstone artifacts cannot be used for their chronological interpretation.