Whitewater appears to be a finely laminated rock. The dark patches we see on the top of Whitewater seem to be remnants of one of those laminae. I was hoping to get a closer look at the darker material, and that is apparently what we are seeing in the MIs from sol 3094. The attached image highlights the approximate location of the MIs on a false color pancam composite from sol 3092.

Interestingly, the dark, vitreous-appearing lamination seems to be thinner than the diameter of the embedded spherule.

You're correct, CR, Whitewater is laminated and not "massive or amorphous"-- I've corrected my earlier description. I was too focused in on one area of the whole outcrop. The laminations appear to be quite variable and the unit is riddled with fractures.

The "Blue Resistant Area" (call it Blue Goo?) on this outcrop appears to be a remnant of a thicker zone-- it has been weathered, and eroded by the wind and is the contact between two rock types (yeah, I've hopped back to the "this is a contact" camp again). So this is a unique spot-- it could tell us what the surface of Whitewater was like at the time that the overlying unit (Kirkwood??) was deposited. Note this puzzle-piece: brushing at the previous IDD location showed that this outcrop has a thin, soft, ochre-colored surface underlain by a light-bluish material. It might be dust, but with the persistent prevailing winds of this area that is less likely and dust has not been seen on the adjacent Blue Crunchy Kirkwood fragments. It could be a weathering rind that occurs on the exposed Whitewater outcrop. Looking closely at this remnant Blue Goo material will tell a lot.

I needs to get off me duff and upload the many views of this outctop area to my photosite. Been putting it off-- give me a couple of days and I'll announce when there are enough up to warrant a visit.

CR-- your location of the current IDD spot is dead-on. Good find.

--Bill

Rock varnish tends to be high in Mn as well as clays, so the composition may help to discriminate among the possibilities.

New MIs in the pipeline:

http://qt.exploratorium.edu/mars/opportuni...ger/2012-10-10/

They've RAT-brushed another, adjacent spot at the second IDD site on the "resistant blue area" on Sol 3096.

And are drooling on a new target: Lindsley, P2575 and P2576, which appears to be bedding-plane outcrop with multiple layers:

http://qt.exploratorium.edu/mars/opportuni...29P2575R4M1.JPG

Thumb-twiddling for the next ODY-pass...

--Bill

Did Oppy drive over some portion of the later MI image coverage area? There are two arcs of what appear to be scratches in the less-durable covering layer on the right side of the image linked below; one large arc and another much narrower arc tangent to the larger one:

http://qt.exploratorium.edu/mars/opportuni...29P2956M2M1.JPG

These "scratch arcs" look decidedly artificial to me.

-the other Doug

Artificial for sure - those are from the rat brush!

Those marks are from either from the RAT brush or the RAT contact ring. I wondered, too.

--Bill

OK -- well, the arcs are far bigger than the outside arc of the RAT's circular footprint. I guess the RAT was turned on and dragged across the surface, eh? First time I've ever seen that.

Another first for Opportunity!

-the other Doug

The brush has a larger and more diffuse footprint than the RAT itself. Outlying bristles could easily cause that exact pattern

Keeping in mind that I have no idea what the RPs did on that Sol (I haven't been on Oppy for almost three months now) the scratches tangent to the RAT brushes could be from the RAT butterfly contact switches. We definitely do not move the IDD while RATing or brushing.

Paolo

X-eye stereo. Separate laminae, equally thin, in unbrushed area.



Thin layer in brushed area also, and "canyon" between brushed and unbrushed areas.

Sol 3098 Navcam pan. Just one missing frame to have the full 360°.

Very good! And there are a couple of spheriodules of unknownst affinity in those stereos.

And thissol, she's moved upslope and north-ish to tasty outcrops. New names listed in theTracking Web as "Site168" and "Chelmsford".

--Bill

Ant103: That's a beautiful and interesting panorama. Your work is always very good. Thanks for posting it.

I wish I could understand the nature of these mounds.

Hay everyone, there are fantastic pancams down today. image White gypsum layer?