AUSTRALO-ASIAN TEKTITES AND A GLOBAL DISA STER OF ABOUT 10,000 YEARS BP, CAUSED BY COLLISION OF THE EARTH WITH A COMET

About 10,000 years ago, at the Pleistocene-Holocene border, some impor tant events occurred: the glaciation stopped abruptly; the sea level e levated, and quick (for 20-50 years) climatic and ecological changes t ook place, leading to the extinction of the so-called <<mammoth>> faun a and exerting a direct effect on the mankind's evolution and appearan ce of civilizations. These and other disastrous events providing a dis tinct boundary between the Pleistocene and the Holocene received no re levant explanation in the Quaternary geology until now. It is shown in the paper that the disaster under study was caused by the collision o f the Earth with an eruptive comet, brought various volcanic tektite g lasses from a remote planetary body. This extra-terrestrial source of tektites is proven by the well-known but not adopted paradox of tektit e age, i.e. a difference in hundreds of thousands and millions of year s between the radiogenic age of tektites (time of formation) and time of their fall onto the Earth. The volcanic nature of tektites is suppo rted (by analogy with volcanic bombs, lavas, tufflavas, and extrusive formations taking into account extraterrestrial conditions) by their l ong and many-stage formation, by ordered trends of composition variabi lity inherent only in magmatic differentiation, etc. Relying on a dive rsity of forms, structure, and composition of tektites, we made an att empt to reconstruct various types of volcanic eruptions. Most likely, the place of volcanic activity was a small or light planetary body of the type of Io, Callisto, Triton, etc. with ice crust, acid upper and relatively basic lower mantle, with small gravitation, without atmosph ere, etc., situated somewhere on the periphery of the Solar System. It is supposed that a very powerful explosion ejected into space some pa rt of a stone-ice volcanic construction, i.e. eruptive comet, accordin g to S. K. Ysekhsvyatsky. The comet hypothesis permits explanation of main features of distribution of tektites over the Earth's surface, va rious forms of their connection with impact craters as well as many ot her features of tektites. The common Earth impact hypothesis for tekti te origin is not able to explain all these facts; it is deeply perplex ed and is severely criticized in this paper. The <<mammoth>> disaster is comparable with the so-called <<dinosaur>> catastrophe at the Creta ceous-Paleogene border, which also was accompanied with impact craters and fall of tektites. An analogy is traced with the collision of the Shoemaker-Levi comet with the Jupiter. Thus, a special class of erupti ve comets, cosmic bodies the most dangerous for the Earth, which are b eyond attention of investigators, is discussed for the first time.