[meteorite-list] Two Questions

[Göran Axelsson]

How about water circulating in areas with hydrothermal activity.
That should be able to drag atmospheric gases into the crust.

With all the evidence of a wetter past for Mars I think it should
be one alternative to concider.

On Earth we have areas with magnesium metasomatose
(spelling?) where seawater containing magnesium is drawn
down into the seafloor and replacing iron in the minerals,
creating magnesite, talc and serpentinite out of olivine and
other minerals.
It would take a lot of seawater to circulate to create the
serpentinite mountains we have here in Sweden.

/Göran

MarkF wrote:

> Hi Eric and List
>
> Its my understanding that an atmosphere is created as much by 
> volcanism as anything else (gravity attracting the gases along with 
> the denser matter which makes up a globe, ect).
> Via volcanoes, gases like H2 O ,SO2 ,CO2   are all generated during 
> volcanism and found in atmospheres, so finding them in mantle rock 
> isn't such a hard thing to consider.
>
> Mark Ferguson
>