It looks like mostly dust on the surface in this region where the clays might be. Do the instruments on CRISM detect subsurface signatures of the phyllosilicates? If it's all under the dust layer, Oppy might have to drag a wheel to scrape it off, like her sister once did unwittingly and uncovered some discoveries. Or maybe just spin a wheel.

Intriguing post from Maxwell:
Can't wait to see where we'll end up...

Could the phyllosilicates be in the dust? I guess you'd still have to have an anchored source nearby or they'd be blown all over the planet by now, but the source itself could be much smaller than the CRISM signatures. Along with Bill, I would be searching for more of those light-colored veins.


Maybe this guy knows the answer. (I was dying to post this earlier in the thread, along with the Tardis and the door, but couldn't find the print.)

We got a significant set of images in the Evening Data Express-- a series of "boot-toe scuff" Pancams in the close-in "systematic foreground" format in full L and R filter sets, command sequence P2559. This is a good indication that Oppy is at or near the site of the CRISM signal.

Meanwhile, read up on CRISM:

http://crism.jhuapl.edu/


--Bill

... Well, this data took 42 years to reach us... It must come from the old Mariners :
"Release Date: Dec 31, 1969" : a nice typo ...

The L2 Pancam view on Sol 2742 and 2743.

Jan van Driel

and another nice one.
The L2 Pancam view on Sol 2743.

Jan van Driel

Colour view of part of "Sheba" outcrop...

Well, this data took 42 years to reach us...


...and shows the value of persistence.

--Bill

Where is this? I'm currently in Arica, North Chile, and can see such things everyday...

Was in that same region a couple of years ago, visited the ESO's VLT, astounding how Mars-like the landscape is there. The Atacama makes the Mojave look like a lush garden! It's the place to go to get a sense of Mars on Earth.

Yep! More Gussev like actually!
Look at this Dust Devil I shot yesterday! They were 10's of them.
Steve S. said recentely in an interview that Oppy is experiencing some cleaning in CY but there is no such a thing as DD

No, or not mainly so, because as you point out dust is too mobile. There wouldn't be a striking hole in the distribution inside the crater, a place that is clearly accessible to dust. The clay minerals must either themselves consist of larger fragments or coat larger fragments of something else, possibly shattered igneous material. Clay minerals as an external weathered layer on harder grains would fit with Bill's suggestion that the clays formed in cracks rather than being the main bulk constituent of a 'clay layer'.

This leads to the question of whether or not the clays formed before the Endeavour impact. Accepting PaulM's obsevation that the clays on Cape Tribulation seem to follow layers I would say this leaves at least two possibilities open. Either, as PaulM suggests, there were clay-rich layers in place before the impact or, perhaps, there were layers of some rock that had the propensity to form clay minerals in fractures produced by the impact, presumably in the continuing presence of moisture. If we are seeing clay signatures from external coatings on many gravel-sized fragments I think that could point to the latter.

It's a complicated place and too early to draw conclusions for sure, but not too early to be thinking about it. I just marvel and celebrate the fact that we are freely provided with so much information that we can do that.

Gathering info for Curiosity?

They did that quite some time ago as well - checking how well the Navcam's can be used for sunfinding.

One result looked like this :
http://marsrovers.jpl.nasa.gov/gallery/all...GTP1926L0M1.JPG

another

http://marsrovers.jpl.nasa.gov/gallery/all...6AP1926L0M1.JPG