[meteorite-list] Tektites lunar/terrestrial
From: Stephen Edward Smith <vickie-steve-smith_at_meteoritecentral.com>
Date: Thu Apr 22 09:43:30 2004 Message-ID: <3B4B3788.83912D27_at_erols.com> Hi all, Another point that is sometimes overlooked is that there is no oceanic crust over 200 million years old. The oceanic crust is continuously being subducted and replenished. We tend to compare to rocks we "know" which are usually highly metamorphic or weathered continental plate rocks . I believe the source for tektites would most probably be an impact event with oceanic crust material. All obvious signs of an impact would be long gone. Steve Smith meteorites_at_space.com wrote: > In this respect it has been noted that tektites closely resemble subgraywackes (Taylor, 1965; Chao 1963). > > And quoting Billy Glass: "With the exception of low water content, there is no chemical difference that distinguishes tektites from terrestrial rocks" > > (p. 16 Microtektites and the Oritin of the Australasian Tektite Strewn Field. Bill P. Glass; May 1968; publications Center For Meteorite Studies, ASU.) > > Though pre-Apollo Mission, this abstract lays out much of what is currently being debated with a strong conclusion that the source for tektites is a terrestrial impact event involving comets in as I said Tunguska type events. Glass gives credence to it in his study of micro-tektites where the Si composition is 48 to 65%-- considerably lower than the larger tektites. > > He also mentions the Earth's atmosphere possibly being blown away by such events, but completely misses the notion that such events, as I have proposed could dissociate the hydrogen-oxygen bond in water and thus offer an explanation as to why tektites lack water in comparison to Earth rocks from which they were derived. > > Regards, > Steve Schoner > http://www.geocities.com/american_meteorite_survey > > On Mon, 09 July 2001, "Frank Cressy" wrote: > > > > > <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> > > <HTML><HEAD> > > <META content="text/html; charset=iso-8859-1" http-equiv=Content-Type> > > <META content="MSHTML 5.00.2314.1000" name=GENERATOR> > > <STYLE></STYLE> > > </HEAD> > > <BODY bgColor=#ffffff> > > <DIV>Hello Karl,</DIV> > > <DIV> </DIV> > > <DIV>You seem to have leapt into the tektite controversy without the benefit of > > a lot of background, instead relying on your gut feeling. A link to a good > > background site to start is furnished below:</DIV> > > <DIV> </DIV> > > <DIV><A > > href="http://www.meteorite.com/tektites/Tekindex.htm">http://www.meteorite.com/tektites/Tekindex.htm</A></DIV> > > <DIV> </DIV> > > <DIV>Your statement below is nowhere close to being correct or you meant > > something else by it . Obviously you have not looked at a thin section of a > > shale which is composed of very fine layers of clay minerals, mica, and organic > > matter. </DIV> > > <DIV>Hope this is of some help.</DIV> > > <DIV>Regards,</DIV> > > <DIV>Frank</DIV> > > <BLOCKQUOTE > > style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> > > <DIV>tektites are so unlike any other terrestrial rocks and actually are > > more</DIV> > > <DIV>similiar in structure to shale than say obsidian...( a common volcanic > > glass)...</DIV> > > <DIV> </DIV></BLOCKQUOTE></BODY></HTML> > > ___________________________________________________________________ > Join the Space Program: Get FREE E-mail at http://www.space.com. > > _______________________________________________ > Meteorite-list mailing list > Meteorite-list_at_meteoritecentral.com > http://www.pairlist.net/mailman/listinfo/meteorite-list Received on Tue 10 Jul 2001 01:12:40 PM PDT |
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