New type of abrasives tools (based on materials of Nothern Angara Holocene assembledges)

The abrasives utilization for the different operation in Holocene assemblages is well-known. The purpose of abrasives use usually determinate by researches as the production of tools of raw organic material or as grinding work of stone axes, axe-adze etc. The comparison of the abrasives from assemblages of Holocene sites in Northern Angara region (Ust'-Kova, Aplinskiy Porog) with the experimental arrow points production results let us extend new type of abrasive. The abrasives of this type used in processes of arrow points or bifacial worked inserts production for pressure platform abrade. This type of abrasives was not described for Holocene assemblages of Northern Angara region and Siberia above. The abrasives of alike functional assignment were described by M. Waters for Gaulte site (Texas) assemblage. We can separate two attribute of this abrasives type of Northern Angara region Holocene assemblages. First and the most essential morphological attribute of this abrasives type is the one or more asymmetric V-type channel located on abrasives surface. Second attribute – the ultratraces of channels inner surface are characterized by intensive grounding and abrading of sand grain and traces.