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

Abstract

About 10,000 years ago, at the Pleistocene-Holocene border, some important events occurred: the glaciation stopped abruptly; the sea level elevated, and quick (for 20-50 years) climatic and ecological changes took place, leading to the extinction of the so-called «mammoth» fauna and exerting a direct effect on the mankind's evolution and appearance of civilizations. These and other disastrous events providing a distinct boundary between the Pleistocene and the Holocene received no relevant explanation in the Quaternary geology until now. It is shown in the paper that the disaster under study was caused by the collision of the Earth with an eruptive comet, brought various volcanic tektite glasses from a remote planetary body. This extra-terrestrial source of tektites is proven by the well-known but not adopted paradox of tektite age, i.e. a difference in hundreds of thousands and millions of years between the radiogenic age of tektites (time of formation) and time of their fall onto the Earth. The volcanic nature of tektites is supported (by analogy with volcanic bombs, lavas, tufflavas, and extrusive formations taking into account extraterrestrial conditions) by their long and many-stage formation, by ordered trends of composition variability inherent only in magmatic differentiation, etc. Relying on a diversity of forms, structure, and composition of tektites, we made an attempt 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 atmosphere, etc., situated somewhere on the periphery of the Solar System. It is supposed that a very powerful explosion ejected into space some part of a stone-ice volcanic construction, i.e. eruptive comet, according to S. K. Vsekhsvyatsky. The comet hypothesis permits explanation of main features of distribution of tektites over the Earth's surface, various forms of their connection with impact craters as well as many other features of tektites. The common Earth impact hypothesis for tektite origin is not able to explain all these facts; it is deeply perplexed and is severely criticized in this paper. The «mammoth» disaster is comparable with the so-called «dinosaur» catastrophe at the Cretaceous-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 eruptive comets, cosmic bodies the most dangerous for the Earth, which are beyond attention of investigators, is discussed for the first time.