ORIGIN OF TEKTITES - AN ALTERNATIVE TO TERRESTRIAL IMPACT THEORY

The Terrestrial Impact Theory (TIT) has won a complete victory over O' Keefe's lunar volcanic theory, but only because the Moon appears to be the wrong place for tektites. Indeed, the TIT ignores strong evidence of their volcanic origin - far from the Moon. The Extraterrestrial Vo lcanic Comet Theory proposes an alternative to both of these theories. Major arguments for an extraterrestrial tektite source are paradoxica l: a great time difference between tektite formation and their arrival on Earth, and also forms, plastic deformations, ice collision marks, vacuum voids, etc. indicating specific conditions of tektite formation such as low gravitational field, lack of atmosphere, interaction of h ot plastic tektites with ice, etc. Major evidence of volcanic origin i ncludes: close analogy between shaped tektites and small volcanic bomb s, and between layered tektites and lava or tuff-lava flows or huge bo mbs; analogy between flanged tektites and volcanic bombs ablated by ga s-jets; long-time, multistage formation of some tektites that correspo nds to wide variations in their radiometric ages; well-ordered long co mpositional trends (series) typical of magmatic differentiation; diffe rent compositional tektite families (subseries) comparable to differen t stages (phases) of the volcanic process. Thus, different types of vo lcanic eruptions under extraterrestrial conditions could be reconstruc ted based on tektite properties. It is presumed that tektites were tra nsported to the Earth by specific eruptive comets, i.e. in the form of ice-tektite agglomerates launched into space by volcanic explosion. M ajor arguments favouring comets include: ice collision marks and impri nts as mentioned above; linear band-like sculpture of the Australasian strewn field as evidence of comet fragmentation and slope or skipping trajectory of separate fragments; compact coincidence of the Zhamansh in impact crater with small tektite strewn field as evidence of steep trajectory of separate comet fragments that disintegrated while enteri ng the atmosphere. The comet-Earth collision under consideration happe ned 10,006 years ago and caused the global catastrophe marked by the s harp Pleistocene-Holocene boundary, i.e. by abrupt climatic changes, t he end of glaciation, mass extinction,etc. This event can be compared with the: ''dinosaur'' catastrophe at the WT boundary 65 Ma, which was also accompanied by tektite fall. All arguments above cannot be expla ined and may be rejected by the Terrestrial Impact Theory. An unbiased discussion is thus necessary.