[meteorite-list] THEORIES OF THE ORIGIN OF TEKTITES, Part Four
From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Sat Feb 18 02:04:54 2006 Message-ID: <002801c63459$9c511110$6553e146_at_ATARIENGINE> Hi, Here's Part Four of THEORIES OF THE ORIGIN OF TEKTITES 12. The Theory that Tektites are Lunaites, or Lunar Meteorites. First advanced by Nininger in 1940, this theory enjoyed renewed popularity in the 1960's, being supported at one time or another by Chapman, Adams, Huffaker, O'Keefe, and Kuiper. But analysis of the actual rocks brought back from the Moon killed this theory outright. 13. The Theory that Tektites are Ejecta from Lunar Volcanoes. First proposed by Verbeck in 1897, revived by Linck in 1928, and again by John O'Keefe in 1976. O'Keefe derived them from deep layers in the Moon that we haven't sampled yet, jetted out by cold hydrogen volcanoes at lunar escape velocities or above. 14. The Theory that Tektites Are The Residue of A Former "Ring" Around the Earth in Eocene Times. John O'Keefe, 1985. The Eocene tektites of North America would be the result of the primary decay of such a "ring," followed by subsequent decays, up to the final decay of the ring in the form of the Australo-Asian tektite strewn field. Please note that this is a variation of No. 9 (above) since the "ring" is composed of tektite material and its disappearance explains why no more tektite material falls to Earth. O'Keefe's "Ring" hypothesis derives from his earlier proposal (1961) of tektites derived from Cyrillid objects, or captured objects in decaying Earth orbit (his really brilliant analysis of the Chant Trace meteors, 1911). There is nothing impossible (or even unusual) about the notion that the Earth may have once or often had a small satellite in decaying close orbit that was disrupted to form a "ring" which would certainly subsequently decay away. Rings are part of the normal Solar System paraphernalia, after all. It's a perfectly reasonable proposal, simply a very hard one to prove or find evidence for. There is a Canadian scientist still pushing the ring hypothesis in a somewhat baffling way on the internet. 15. The Theory that Tektites are Residues from Solar Prominences: Himpel, 1938. This notion was advanced to explain the Ice Ages (which it doesn't). Tektites are not solar in composition, hence this is basically just a whacky notion. 16. The Theory that Tektites are Interstellar in Origin: Krause, 1898, and Kohman, 1958. This theory would explain the uniqueness of tektites by pushing them right out of the Solar System altogether, but the lack of CRE (cosmic ray exposure) in tektites argues rather strongly against this idea. Had enough? McCall quotes Dr. George Seddon as remarking to him "Before hearing you lecture I thought tektites were quite incredible; now, I know they are impossible!" The fact that we currently have a "consensus" view on the origin of tektites in terrestrial impacts does not really mean the problem is solved. We had a consensus view that they were volcanic for a century or so, too, but, as A. S. Woodward said in 1894, "Where they come from, no one knows." Some factors and basic tektite facts to bear in mind while evaluating the validity of various tektite origin theories: Continued in Part Five (tomorrow or the next day) Sterling K. Webb Received on Sat 18 Feb 2006 02:04:50 AM PST |
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