Re: extreme flow beaches

David Yeamans, CST-7, 5-8832, dryeamans@lanl.gov (dryeamans@lanl.gov")
Fri, 03 Oct 1997 13:52:56 -0600


In response to my query about isotopic signatures in quartz crystals being
used to identify the nature of perched sediment fields I received this.

>David,
> Interesting question. Certainly, all quartz is not alike. There are
>minor but measureable chemical differences which lead also to crystal
>structural differences from sample to sample. The difficulty is not in
>measuring the differences but in relating the differences to source, etc.
>What you propose may be possible.

and

>Hi,
>
>I'm not sure I understand a couple of aspects of your email...are you
>asking for collaborators or just information? How does the source of the
>quartz tell you it is lacustrine or fluvial? I would say yes, it is
>possible to fingerprint quartz from sufficiently different sources.
>Probably a combination of techniques would give the most unambiguous
>answers. Two methods that come to mind are oxygen isotopes and electron
>spin resonance. A lot of work would have to be done to characterize the
>potential source formations; furthermore, the quartz in each has to be of
>sufficiently different origin for this to work (eg. plutonic vs. volcanic
>vs. metamorphic) for the oxygen. Regarding ESR fingerprinting of quartz
>you should check out the paper by Toyoda and Goff (1996) in the 47th New
>Mexico Geological Society Guidebook, "Jemez Mountains Region."
>

So, fellow dilletantes, the stakes may have been raised.

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