[Rockhounds] Another extinction impact-13 KYA

[Tim Fisher]

Shocked quartz, tektites, an impact crater, and irridum were all mentioned
as elements of a meteor strike that are missing from the 12,900 BP
extinctions.

-----Original Message-----
From: rockhounds-bounces at lists.drizzle.com
[mailto:rockhounds-bounces at lists.drizzle.com] On Behalf Of Dora Smith
Sent: Friday, January 02, 2009 9:49 AM
To: Rockhounds at drizzle.com: A mailing list for rock and gem collectors
Subject: Re: [Rockhounds] Another extinction impact-13 KYA

Dora the Explorer is familiar with arguments on the dinosaur and related 
lists on what wiped out the dinosaurs.

If a meteor impact altered the climate, it should have left more of a 
signature than microscopic strange looking diamonds.   There are a number of

particular minerals, I think some of them radioactive, that are left behind 
by such an impact.   The tricky part is that many or most of them are also 
left by monster volcanoes, and especially if, as at the end of the 
Cretaceous, you have evidence that both kinds of events happened it can be 
hard to figure out what really did happen.

I'm not right up on what those minerals are, and don't believe it ever 
occurred to me to put it on Dora the Explorer's catastrophe pages.   But a 
little research would turn them up.

I also question if such an event would not have had some kind of perceptible

center of distribution, especially if the diamond particles are only found 
across the U.S.

Yours,
Dora Smith
Austin, TX
tiggernut24 at yahoo.com

----- Original Message ----- 
From: "Kreigh Tomaszewski" <Kreigh at tomaszewski.net>
To: "Rockhounds at drizzle.com: A mailing list for rock and gem collectors" 
<rockhounds at lists.drizzle.com>
Sent: Friday, January 02, 2009 11:09 AM
Subject: Re: [Rockhounds] Another extinction impact-13 KYA


> The story is also up at the Washington Post
> http://www.washingtonpost.com/wp-dyn/content/article/2009/01/01/ 
> AR2009010101490.html?hpid=topnews
>
>
> On Friday, Jan 2, 2009, at 10:11 America/Detroit, J Bryan Kramer wrote:
>
>> <
>> http://www.nytimes.com/2009/01/02/science/ 
>> 02impact.html?_r=2&partner=rss&emc=rss&pagewanted=all
>>>
>>
>> I never heard of hexagonal diamonds, isn't that graphite's crystal
>> structure?
>>
>> BK
>> -- 
>>
>> ""It often seems to me that the night is much more alive and richly 
>> colored
>> than the day."
>>
>>                       Vincent van Gogh
>> J Bryan Krämer
>> North Florida, USA
>> photos at:
>> http://pbase.com/photoburner
>>
>>
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