Mike,

I have taken another look at your thin section and performed some

quantitative analyses on it with the microprobe. As far as I can see, it

is composed mostly of the minerals feldspar and quartz. I even found

some apatite, a calcium phosphate mineral. This is typical

of felsic volcanic rocks, that is, ones that are silica-rich like dacite

and rhyolite. That doesn't jive with the major element analysis that you

faxed me, which has pretty low silica (49 wt.%), which is more typical of

a basalt. I'm not sure what to make of this inconsistency, but there is

nothing to suggest to me that this rock is anything other than

terrestrial in origin. If you want me to take a look at your plots,

that's fine. Maybe you spotted something I've missed.

Jamie Gleason

****************************************************************

James D. Gleason

Lunar and Planetary Laboratory

University of Arizona

Tucson, AZ 85721

(520) 621-7984 (phone)

(520) 621-6783 (fax)

jgleason@gamma1.LPL.arizona.edu