Zhamanshin Impact Crater and Tektite Problem

The Zhamanshin crater (Northern Aral region) is the only impact crater on the Earth where impactites and tektites coexist. The tektites are represented by two varieties, irghizites and acid zhamanshinites, which have no analogues among the target rocks. So, they are supposed to be extraterrestrial volcanic glasses. The crater coincides with the stretch of the giant Australian-Asian belt of tektites. The crater is closely connected with the belt judging by a sharp difference between the isotope age of tektites and their geologic setting, i.e., by the known age paradox. A geochemically abnormal layer enriched with Ni, Co, Cr, Mn, Ir, and other elements dated by the Pleistocene-Holocene boundary is associated with the crater. In this period, a global catastrophe took place, which resulted in the mammoth fauna extinction. According to the data described in the paper, this catastrophe was caused by a cosmogenic reason, namely, by the collision of a large tektite-bearing comet with the Earth.