[Rockhounds] Something going on in Yellowstone

[Dora Smith]

OK, folks.  I keep posting the link, and people keep posting all sorts of 
thigns that indicate they didn't look at it.

At http://www.tiggernut24.com/catastrophes.html, you will find that link and 
may others.   Some of them recent and technical.

Yours,
Dora Smith
Austin, TX
tiggernut24 at yahoo.com
----- Original Message ----- 
From: "Kreigh Tomaszewski" <Kreigh at tomaszewski.net>
To: <nospam at orerockon.com>; "Rockhounds at drizzle.com: A mailing list for rock 
and gem collectors" <rockhounds at lists.drizzle.com>
Sent: Thursday, January 01, 2009 5:59 PM
Subject: Re: [Rockhounds] Something going on in Yellowstone


> Or take a look at the Wiki article at 
> http://en.wikipedia.org/wiki/Yellowstone_supervolcano
>
>
>
> On Thursday, Jan 1, 2009, at 12:31 America/Detroit, Tim Fisher wrote:
>
>> It has happened many times with the same hotspot. Google McDermitt 
>> caldera.
>>
>> -----Original Message-----
>> From: rockhounds-bounces at lists.drizzle.com
>> [mailto:rockhounds-bounces at lists.drizzle.com] On Behalf Of Dora Smith
>> Sent: Thursday, January 01, 2009 6:28 AM
>> To: J Bryan Kramer; Rockhounds at drizzle.com: A mailing list for rock and 
>> gem
>> collectors
>> Subject: Re: [Rockhounds] Something going on in Yellowstone
>>
>> I'm the original not expert.  I learn something totally new about it 
>> every
>> five minutes.   I did learn in teh course of reading through some of that
>> stuff that apparently the basalt flows predate the hot spot eruptions, 
>> some
>> ancient - shield volcano?
>>
>> I've no idea when such a thing happened in North America.    And to be 
>> more
>> confusing I got the impression that there were more ordinary eruptions
>> before that happened.   Not Earth didn't have an entire history before 
>> teh
>> end-Permian extinction, and there was a smaller flood basalt eruption in
>> India at the end of the Cretaceous, but I keep thinking that a flood 
>> basalt
>> eruption in North America must coincide with the development of the crust
>> itself if I never heard of it before.
>>
>> But it sounds like you're not familiar with the Yellowstone caldera at 
>> all.
>> This is a very different type of volcano, and they only came to 
>> understand
>> it since I graduated from college 30 years ago.    VERY recent.  Hah, 
>> hah,
>> hah.    Santorini, the volcano that may be associated with the Exodus
>> phonemena, was of this sort, and so was the eruption of Toba in the
>> Phillippines 75,000 years ago that brought the human race to the brink of
>> extinction.   Not a flood basalt, but the next biggest monster. 
>> Sometimes
>> very thick magma builds up in a huge, abscess-like crater underground 
>> under
>> such conditions that it can't easily erupt to the surface.    When it 
>> does
>> that's a problem enough - you get pyroclastic flows and ash clouds that
>> travel some little distance.   Like in Pompeii, and Mt. St. Helen's.
>> But large caldera volcanoes erupt rarely and alter Earth's history when 
>> they
>> happen.    If Yellowstone blew it would kill all life on half the North
>> American continent and the climate changes would  starve nearly everyone
>> else on the planet.    Problem is it's due to blow and pressure is 
>> building
>> up, and noone knows how much pressure has to build up or what it all 
>> means.
>> The cycle of that volcano is in hundreds of thousands of years - not our
>> time scale.    Confusing the issue is that the volcano is caused by a 
>> hole
>> in the Earth's crust that moves over time, relative to I think the North
>> American plate.  Unfortunately it hasn't at this time moved out from 
>> under
>> the last caldera, but it does appear to have moved in a direction 
>> consistent
>> with its previous movement.   If the volcano significantly changed its
>> geology it could conceivably begin to erupt less violently.  Though part 
>> of
>> the violence is due to the nature of the magma rather than the hard cap
>> formed by the previous eruption.
>>
>> Several years ago I got interested and put together a web page.
>> http://www.tiggernut24.com/catastrophes.html   There's an associated page 
>> on
>> teh geology of Sumatra and subduction faults that isn't relevant to much
>> that goes on in North America (except in teh Cascades).
>> http://www.tiggernut24.com/earthquake.html   I begin with a link to the 
>> web
>> pages of a PBS special a few years ago.   And the Wikipedia article, and
>> some general geology of hot spots and caldera volcanos.
>>
>> One thing that complicates the issue is that between the monster 
>> eruptions
>> every 600,000 to 700,000 years, Yellowstone does have smaller and more
>> normal eruptions, and these have left more routine lava flows in the 
>> area.
>> I'm not yet up on what kinds of volcano flows leave what kinds of lava
>> deposits, and it's very relevant to understanding Yellowstone.   I 
>> thought
>> people here would know that.   On my web site I also have links to some 
>> new
>> technical papers that ought to include that information.
>>
>> Yours,
>> Dora Smith
>> Austin, TX
>> tiggernut24 at yahoo.com
>>
>>
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