[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Fw: Cosmic rays and the estimation of paleo-elevation



I sent a copy of this thread to John Gosse (one of the authors of the
paper), and below are his short comments.  It appears that this area of
research is still virginal (PhD dissertation, anyone?).

Posted with his permission.

<pb>
--

--------- Forwarded message ----------
From: John Gosse <John.Gosse@Dal.Ca>
To: Phillip Bigelow <bigelowp@juno.com>


Good question.  The altitudinal effect is more than 20X for probable 
extremes of dinosaur habitat.  I wonder how long the targeted dinosaurs
live for, and if
they can find dinosaurs that have been significantly shielded rapidly.
--john


> From: Phillip Bigelow <bigelowp@juno.com>
> To: dinosaur@usc.edu
> Date: Thu, 27 Jul 2006 14:06:57 +0000 (pd)
> Subject: Re: Cosmic rays and the estimation of paleo-elevation
> Message-ID: <20060727.140703.-993707.1.bigelowp@juno.com>
>
>
> I found a reference on cosmogenic paleoaltimetry!
>
> Gosse, John C., and F. M. Phillips. 2001. Terrestrial in situ
cosmogenic
> nuclides: theory and application. Quaternary Science Reviews 20, no.
> 14:1475-1560.
>
> Here are the elements that have stable *distinctive* cosmogenic
isotopes:
> (I left off the subscripts and superscripts)
>
> He, Be, C, Ne, Al, Cl
>
> Apparently, these *distinctive* isotopic changes are measurable in
rocks
> with as little as 100 years exposure to high levels of cosmic rays.
>
> The authors didn't mention the potential use of this technique to
measure
> the amounts and ratios in bones that have lain on (or were shallowly
> buried in) high altitude soil.  But they *do* claim the method works
well
> for "virtually any lithology".  *Any* lithology, hmmm?
>
> Now, we're probably all thinking the same thing:  What would 100 years
> (or even better, 1000 years) of exposure to high altitude cosmic rays
add
> to the shallowly buried bones of a mountain dinosaur?
>
> Can we segregate dinosaur taxa into "cosmogenic isotope categories" by
> this method?
>
> <pb>
> --
>
>
>
>
>
>
>
> On Thu, 27 Jul 2006 11:31:21 -0800 Michael Tapp <fsjmt2@uaf.edu>
writes:
>> Sorry if you could read this twice....
>>
>> Hi Phil,
>>
>> Jennifer McElwain at the Field Museum has been doing some work with
>>
>> fossil plants and paleoaltimetry, using the stomatal index i
>> believe.
>> If you have any plant matter in your conglomerate, this might be
>> something to look into. I know I have a recent paper on it, but i
>> can't seem to find it right now, so i've attached a pdf with a quick
>>
>> GeoRef search with some ref's.
>>
>> Cheers,
>> Michael
>>
>> --
>> Michael Tapp
>> Department of Geology and Geophysics
>> University of Alaska Fairbanks
>> fsjmt2@uaf.edu
>> 907-474-7585
>> ----------------------------------------------------------
>> "Given enough time, the proper resources, and access to some really
>>
>> toxic stuff, one can probably dissolve just about anything except
>> Peep eyes." www.PeepResearch.org
>>
>>
>
>
>
> --
> Associate the following words:  "Feisty", "Caffeine", "Weird",
"Neither",
> "Rotweiller".  The answer will be provided in a future post.
>
>
>
>



Dr. John Gosse
Canada Research Chair
Earth Systems Evolution
Associate Professor
Earth Sciences
Dalhousie University
Halifax, NS Canada
B3J 3J5
www.dal.ca/cnef