On Fri, 14 Dec 2001 Spudboy100@aol.com wrote:
> As far as I know, outside of purported outgasings on the lunar surface, it is
> indeed quiet. But this has not always been so. Early in the moon's formation
> it was geologically active, as was the earth's surface. Both were kept
> active, in large part, to the steady slammimgs of large meteorites, which by
> hydrostatic shock, helped induce volcanos.
provides, for the moon, an example of what they claim is
"a variety of impact, volcanic, and tectonic features."
but I read it as a thin-crust punch through...
> "This basin formed 3.87 billion years ago when an asteroid 50 to
> 100 kilometers across slammed into the Moon."
That is quite a bit different from high temperatures, esp. high
pressure gases derived from water vapor, CO2, S, etc. causing
a "real" volcano.
I suppose we have a "definition" problem here. I'd say that lava
flows per se do not contribute to concentration of specific
minerals to any significant degree. At best they probably give
you access to some of the heavier core material which would have
a somewhat different composition of heavier elements.
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