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Re: Clays in Meridiani.

Subject: Re: Clays in Meridiani.
From: "Robert Clark"
Date: 13 Sep 2006 16:15:12 -0700
Newsgroups: sci.astro, alt.sci.planetary, sci.geo.geology, sci.physics
jonathan wrote:
> <marsfossils@xxxxxxxxxx> wrote in message
> news:1157662724.770912.26740@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> > Interesting.  Thanks.   For those of us who didn't know what nontronite
> > clay is....
>
>
> Remember the very first question that arose after Opportunity landed?
> Why does the soil act like it's clay?
> http://marsrovers.jpl.nasa.gov/gallery/all/1/p/001/1P128287557EFF0000P2303L2M1.HTML
>
> If Mars has been dry and irradiated for hundreds of millions of years,
> there's
> no way the soil should be clay-like. It should be sand-like, or powdery.
> Yet, there it was.  An intermediate form and grain size.
>
> From day one a mystery.
>
> ...

 A good point. Two separate and independent observational means show
there is seasonally varying water content on the Martian surface: one
by thermal infrared spectra, the other by the Gamma Ray-Neutron
Spectrometer.
 TES and Mini-TES spectra showed seasonal variations of carbonate dust
on the surface. It was suggested this was formed from water vapor.
However, on Earth in nature carbonate is formed  from *liquid* water.
It is very likely it is formed from liquid water on Mars as well:

From:  Robert Clark
Date:  Sat, Feb 11 2006 10:32 pm
Email:   "Robert Clark" <rgregorycl...@xxxxxxxxx>
Groups:   sci.astro, alt.sci.planetary, sci.physics, sci.geo.mineralogy
Subject:  Could We Make A "Solar Still" On Mars?
http://groups.google.com/group/sci.astro/msg/95e5bae350f8c285?

 This report shows clays can be formed in short times under martian
conditions:

MINIMUM TIMES TO FORM CLAY IN MARTIAN SURFACE AND NEAR-SURFACE
ENVIRONMENTS.
L. Browning1, G. J. Taylor2, and D. Pickett1
1Center for Nuclear Waste Regulatory Analyses, Southwest Research
Institute, 6220 Culebra Rd., San Antonio, TX 78228 2 Hawai'i
Institute of Geophysics and Planetology, University of Hawaii,
Honolulu, HI, 96822
Lunar and Planetary Science XXXIV (2003) 1708.pdf
http://www.lpi.usra.edu/meetings/lpsc2003/pdf/1708.pdf

 I suggest searching the infrared spectra to see if the signature for
clays also varies seasonally as does the carbonate dust signature.
 If it does then this will mean the clays are currently forming and
will imply they are also being formed from liquid water as is the
carbonate.


   Bob Clark


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