NEW GEOCHEMICAL EVIDENCE FOR THE YOUNGEST TOBA-TUFF IN INDIA

New geochemical data on tephra samples from a layer present at several archeological sites in India support correlation of this layer to the Youngest Toba Tuff, erupted from northern Sumatra about 74,000 yr ago , The data show that the Indian tephra layer is not a correlative of o lder tephra erupted from Toba, as has been suggested on the basis of a rtifact assemblages, Previously published geochemical data on the Indi an tephra beds was based on bulk ash samples containing mineral and cl ay contaminants, and the resulting variability in analyses did not all ow identification or discrimination of individual eruptive events, Our new data were collected on individual glass shards and small, purifie d glass separates which have greater resolving power in fingerprinting , Acheulian and Paleolithic artifacts found at some of the Indian teph ra sites do not reflect the antiquity of the tephra bed, as they occur in fluvial sediments and may be reworked. (C) 1995 University at Wash ington.