[rollei_list] Re: A Picture That Mattered to Me
- From: Peter Mattei <petermattei@xxxxxxxxx>
- To: rollei_list@xxxxxxxxxxxxx
- Date: Tue, 30 Mar 2010 16:26:16 -0700
Andrew, K-T extinction occurred at 65+/- *million* years ago...not in the
60-80k range. Much work and study has been done after the Alvarez team (UC
Berkley) considered the Gubbio clay horizon in the early 70's. After that, a
flurry of scientists have theorized both impact events and eruptions as the
"big one". Current thought is focused upon definitive impact events in
Canada and the Yucatan. Peter Mattei, geologist
On Tue, Mar 30, 2010 at 4:15 PM, Hagner, Andrew <Andrew_Hagner@xxxxxxxxxx>wrote:
> Marc:
>
>
>
> You threw me on a loop. Instead of working I got into reading the
> Wikipedia on Neanderthals. Pretty fascinating stuff. The dates that I saw
> quoted do not seem to exceed 60,000-80,000 years ago. This brings a bit of
> a memory for me.
>
>
>
> In 1993 I was travelling through Sumatra and spent some time on the Samosir
> Island on Lake Toba. Fascinating old culture and stunning landscapes.
> Actually, all my B&W photographs were taken with my Rollei GX. When we
> finally left the island, the plane flew over Lake Toba and I could not help
> but notice the characteristic shape of the lake. It looked to me like a
> caldera. Then I also read in the guide that the lake and the rock
> formations were dated by the Dutch Geological Survey as being about
> 60,000-80,000 years. So, having taken some geology during my school years I
> formed a “personal” theory of this huge volcano exploding and wiping out the
> dinosaurs whose extinction dated within that time span as I remembered
> then. BTW the lake, if I recall correctly, is something like 40 km x 80 km
> in plan view. If Krakatau (which in 1883 was just a relatively small
> island) explosion could cool the global temperature for several years due to
> dust in the atmosphere, what impact on the climate would have an explosion
> of the Lake Toba size volcano?
>
>
>
> Then recently I read that Toba, now classified as a caldera, is considered
> to have been the biggest or one of the biggest volcanic eruptions in the
> Earth history. It coincides with the extinction of the dinosaurs (kind of)
> and worse, it is considered that it almost wiped out all human population
> with the exception of some 2,000 surviving in Africa. Which means that we
> almost went totally extinct! According to the article, this is the result
> of relatively recent genetic research. Apparently, the human race as we
> know it now stems from the survivors of the Toba Volcano cataclysm.
>
>
>
> Thanks for the link Marc, - Andrew (now back to work).
>
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