[meteorite-list] Re: tektite crater?
From: meteorites_at_space.com <meteorites_at_meteoritecentral.com>
Date: Thu Apr 22 09:43:32 2004
I also address this point in my response to Kelly in "Tektites II" which is awaiting approval from the list moderator (62,000 bytes when the limit is 40,000). In short, Kelly mentions Dr. Wasson theory that there were multiples of Mega Tunguska events. I think in light of Shoemaker Levy and the nature of some comets that are apparently very fragile, this could be as you outline below, the mechanics as to how tektites formed. Though a bit complicated, it could be the case. As for the composition of tektites themselves, some point out that they have compositions that are not like terrestrial rocks, others say they do. But in thinking about this problem-- what if they are more akin to the silicate dust grains that *might* exist in comets. And from the perspective of these dust grains how is the water ice and gas ice mixed. It is a homogeneous mixture, or is it a crystalline assemblage with the silicate grains intersparsed throughout?
And when the cometary mass(s) enter the Earth's atmosphere is the gas and water ices sufficiently tranparent to allow the intense infra-red radiation to penetrate down into it thus augmenting disruption leading to the comet's demise in a Mega Tunguska event, rather than striking the ground as Kelly proposes as an argument against my comet-explosion theory? I think the key to resolving the tektite dilemma is to have a comet sample return mission. Comets are the most likely candidates for tektites, and my hunch is that the silicate material that is in comets will coincide with the bulk material that we find in tektites. In other words, it could be that tektites are the residues left over when a comet disrupts on the Earth in a Mega Tunguska event. The ice and gasses are gone, incorporated into our oceans, and air, but the tektites are the silicates that have been vaporized in the event-- recondensed, and now present on the Earth's surface to puzzle us
Chris Sharpe wrote:
> I take your point.
> How about a cometary stream like Shoemaker Levy impacting over a short period of
> time but along a line running from Australia up into Indochina?
> The "cometary stream" initiates a series of Tunguska like airbursts that created
> enough energy to fuse material to glass. Maybe Tunguska was only a small example
> of this sort of phenomena and didn't produce enough energy at the surface to melt
> and blow away this molten material.
> If Hydrogen was in free association then maybe a Hydrogen bomb explosion orders
> of magnitude over what we have experienced? The more I try to visualise it the
> more it seems possible.
> Cheers to both, it all makes for interesting reading.
> Chris Sharp
> ----- Original Message -----
> From: "Kelly Webb" <kelly_at_bhil.com>
> To: "Chris Sharp" <casper_at_spiderweb.com.au>
> Cc: "Meteorite List" <meteorite-list_at_meteoritecentral.com>
> Sent: Monday, July 16, 2001 5:32 AM
> Subject: [meteorite-list] Re: tektite crater?
> Hi, Chris,
> Woodleigh is big enough to be a major candidate for some extinction,
> no doubt about it! (There's an unexplained one at 205 million years
> You'll notice that this one's buried 100 meters deep. That is, it
> took 200,000,000 years or more to bury it only 100 meters; that 1/2
> meter per million years. The proposed (and undiscovered) 114 km crater
> that might have (should have) produced the Australasian tektites would
> have to be only 800,000 years old. How deep could it be buried (if at
> Sterling K. Webb
> Chris Sharp wrote:
> > Its in the area but wrong date?
> > <http://www.mining-australia.com/features-crater.htm>
> > Chris Sharp
> Meteorite-list mailing list
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Received on Mon 16 Jul 2001 11:15:45 AM PDT