The importance of silica in desert varnish

“Baking black opal in the desert sun: The importance of silica in desert varnish”
http://geology.geoscienceworld.org/cgi/content/abstract/34/7/537

“NEW INSIGHTS INTO NATURAL RECORDERS OF PLANETARY SURFACE ENVIRONMENTS: THE ROLE OF SILICA IN THE FORMATION AND DIAGENESIS OF DESERT VARNISH AND SILICEOUS SINTER.”
http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1272.pdf

“How desert varnish forms?”
http://adsabs.harvard.edu/abs/2005SPIE.5906..276P

I googled "desert varnish" "opal a". These are the first of 27 hits.

test

I read 'em. What r u getting at?

Spirit discovered rock surfaces composed of almost pure silica gel. Spirit is heading on down this “silica gel highway” making Ratt brushes as she goes. One such brush is shown in Darwin’s reply 24 above, showing the remarkable contrast in albedo before/after the brush. Spirit will be continuing this work for maybe a month.
The brown stain on the silica gel (opal-a) of the surface rock is almost certainly desert varnish. Desert varnish does not definitely imply biological activity: there is still competition in thoughts on the matter. For instance, please see
http://www.psi.edu/~rperry/perry/howdvspie.pdf
However, for now I conclude that the berries of Meridiani are biological cysts feeding on the desert varnish. I’m still learning, of course, but for now I think these are the most logical deductions. The connection between these berries and those with which we have become so familiar is, at most, a matter of biological speciation.

[link]

The dark nodules in desert varnish might be biological waste product,

Herny,

You think like me, come join us on the "We Never Forgot About Mars Thread" in the Discussion section of The Hidden Mission Forum.

You have to join but it's painless.

I need backup haha!

http://www.keithlaney.net/TheHiddenMissionForum/index.php

it may be some kind of fossil fuels or it may be some of the lava particles.
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ragavendra

sreevysh corp