We have a wealth of info on this spot. I'd like to hear from Don and Tim on this, too.

Oppy has bumped slightly and is now IDDing the "Blue Resistant Areas" on the current outcrop.

http://qt.exploratorium.edu/mars/opportuni...ger/2012-10-07/
http://qt.exploratorium.edu/mars/opportuni...ger/2012-10-08/

are the Exploratorium pages for the current MI interest.

And most fascinating is this one MI:

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

Whoa.

--Bill

It looks like a...sheet of ice??

Or even, at the other end of the spectrum, something glazed over by high temperature.. like Martian ceramic.

Whoa indeed!!! I'm dying to find out what this really is!

Not ice-- temperature and pressure are wrong. It's probably a vitreous or microcrystalline or crystalline material polished by ages of wind erosion and dusted off with the RAT brush. This puzzle-piece has many possibilities, we need to know more about it. Yummy.

--Bill

Wider angle view...



(best I can do, look forward to seeing someone do it properly! )

How about a "desert varnish?" The stuff's clay, after all. And it looks a heck of a lot like what we're looking at.

We don't know if this is the clay yet!

There is a circular feature with an irregular centre at about half past ten on the brushed area that almost looks like a sliced spherule.

Wowsers. Speaking for myself, dburt’s devitrification hypothesis with regard to the new berries just went to the top of the list. This is looking more and more like an impact generated pseudotachylite deposit. Vitreous, devitrification crystals, veining, quench features – it all seems to fit. The now seemingly shallow fine clay like deposits could well be the result of weathering of this glass – residual clay.

A degree of wild shooting from the hip there, but to generate such in this position would imply a product of the Miyamoto event. Massive impact generated thermal shock supplemented by material depositing close to the Miyamoto rim passing through the superheated cloud.

No water here then.

Still arm-waving and hopping back-and-forth here, but this is seeming more and more like the contact between the "kirkwood unit" and the "whitewater unit". The Whitewater unit is variably laminated and (fairly amorphous and massive, but )I have the impression that this surface is a bedding plane.

This is a wondrous place.

--Bill


(corrected description of 'whitewater')

Serpens, much appreciate the vote. I also couldn't help notice the radiating structure of the outer rind of the cross-sectioned new berry referenced by Bill Harris above. Also agree that the "punky" surrounding rock looks far more like clay-alteration of some type than any type of sedimentary rock (including clay-rich shale). Still thinking about the possible significance of the glassy-looking coating - is it an exposed fracture fill, or an outer weathering product, or something else?

I keep hopping between "exposed fracture fill, or an outer weathering product, or something else" myself. And the more I flip through the images we have thus far the more hopping around I do-- it could be "all the above". My initial thought was that the "blue resistant areas" are the remnants of a fracture fill, but the split new-berry threw that idea into a tizzy.

We'll have more images to review tomorrow...

--Bill

I'm more fascinated with what appears to be a flow pattern in the "varnish," resulting in mini-lobes that appear to flow from right to left across the image.

I've never seen desert varnish freezing in any kind of flow pattern before... at least, not unless it comes from transient moving water.

-the other Doug

True. But what makes you think that it is desert varnish?

Indeed. That's why I put "varnish" in quotation marks the first time I used the word. It's some kind of hardened layer, but the look of flow along its top really makes me think of something that splashed into a sheet then "froze" in place.

-the other Doug