[X] My Assistant

[akuo]

Spirit is still at the little outcrop Peace. While there might be issues with the dust storms, it looks like that there really is something scientifically interesting here. As Steve Squyres said "Spirit is now the exciting rover".

They've spent this week looking at the same spot on the outcrop. I am not sure, but it looks like they've ratted there maybe three times. At least the hole is getting deep:

http://qt.exploratorium.edu/mars/spirit/mi...HPP2957M2M1.JPG

Peace looked the same to me from the outside as Pot of Gold. Pot of Gold was too small to be properly ratted, so we never saw its insides properly. The inside of Peace looks similar to Bubbles/Champagne to me - a mishmash of different things but not as angular as Bubbles.

http://qt.exploratorium.edu/mars/spirit/mi...69P2977M2M1.JPG

I hope the scientists will tell us their thoughts soon, or maybe there is a geologist here who can say something :).

[aldo12xu]

I mentioned this on a couple of other posts, but nobody has really followed up on it. I think as we're getting closer to crater rim, we're seeing ejecta blocks that were probably thrown out from deeper layers in the Columbia Hills. Some blocks contain subrounded knobs which could be volcanic fragments/bombs. Others are more friable with suggestive layering.

This paper describes the Columbia units as being possibly volcanosedimentary in origin: http://www.agu.org/pubs/pip/2004JE002327.pdf

I think some of the features seen in the MI photos, like the presence of angular to subangular grains and the variety of grain sizes, suggests that the rock was originally vocaniclastic, perhaps, say, an air fall tuff. (There are some hints of cinder cone volcanism northeast of Columbia near Thira Crater.) The outward appearance of Peace (friable and similar looking to Pot of Gold, deep RAT hole) suggests that the rock has been strongly altered. As for the type of alteration process, well, that will depend on what the spectrometer finds. The alteration could be related to the flood waters that filled Gusev Crater around the end of the Noachian Era, 3.7 billion years ago.

My guess is that Peace and Pot of Gold were thrown out from the same layered units underlying/making up Columbia Hills.