That's interesting. For some reason, I hadn't seen that Nov. 18th update mentioning the basaltic composition. I had only seen Steve Squyres' earlier note about the dark cobbles not being meteoritic.

Wouldn't you think that large, weathered boulder (rubble heap) nearby would be a target they'd want to investigate?

It sure is, and I can't wait to get up close and personal with it. There is definitely something different about that lower layer.


The nearby rocks are really intriguing, especially in false color. Parks (aka, Turkey) appears exceptionally dark in all the filters. That's not true of all the cobbles and pebbles lying about. The bedrock in this area has really captured my attention. I've found quite a few interesting features, several of which are apparent in one particular Pancam composite taken on Sol 657, which I have annotated and attached.

I have more questions than answers. Recently the bedrock has displayed contrasting color variations across short distances. In the false color images the rock color jumps from the typical cream colors to blues and grays across fractures and bedding planes. I can't help but wonder if some kind of local but pervasive mineralization is being displayed.

We have also been seeing some new features in the bedding. I haven't been able to pin them down, yet. I wonder if they are somewhat more irregular concretions, or a sedimentary structure. I can see some similarities to certain soft-sediment deformations, but sedimentary structures are so diverse, and there are so many I have never seen in person.

Rocks here are also showing something that resembles the rinds seen previously, but it has a different color. Other images show this stuff wrapping around fractures and onto bedding planes, and even merging into what appear to be irregular concretions.

Oh, and then there is the rock with the vertical fractures filled with some kind of mineralization. We've seen other examples recently, but this is the first I noticed that wasn't on the outside edge of one of the blocks.

This is an fantastic spot that Oppy is studying now. Good observations on your Sol 657 image: those color and textural changes have been noticable over the past few Sols in this area. There are a lot of interesting L257 images here, I'm just now starting to work on them.

I think the "new rind or mineralization along bedding" that you note is mineralization. On the attached image the rock at the right center is displaced from the bed to the left, both of which are overlain by the cream-colored rock in the upper right, and the bedding mineralization can be clearly seen. In addition to the subtle changes in color, there is also a notable rust-colored dust associated with the usual blueish "hematite dust" of the fractures.

Here we are, kneeling on this wonderful outcrop, can't find the handlens or scratch plate, and the carpal tunnel is acting up... ain't life wonderful.

--Bill

I agree this is a great area, so many textures, shapes and colours even without the IDD a lot could be learned from here. Is the mini TES still working OK.
The shape in the bottom left hand corner looks like a imprint in the dust/sand where a rock has been removed by some means or could oppy have made this mark.
Perhaps I'm seeing negative relief where there isn't any.


Reckless

Good catch! I was so befuddled by the weirdness in the center of the image that I don't notice that weirdness in the left corner.

Evidently someone at Cornell thinks this is notable, too, since there is a L257R2 sequence at the JPL site. Attached is an L257. I've got honey-do's to do, so I'll leave the stereo pair for later and/or for someone else.

This "depression" is only one weirdess I see; what are two (or more) others?

Hmmmm....

--Bill

It may because I am not a geologist, but most descriptions of unusual terrain features, with or without accompanying graphics, leave me quite confused.

Your excellent labeled graphic was a complete exception. I felt confident that I could actually see the features that you were talking about.

I also could see Bill Harris's depression. When it comes discovering weirdess, it is hard to know what is normal. However, for what it's worth, I think I see some unusual squiggles or "ripple lines" on the rock in the upper right of his [ Bill's ] graphic. They are on the top layer of the rock. They remind me of those marks that indicated flowing water back at Eagle Crater. However, they don't seem to be part of the layering?

Jack

I don't think anybody in their wildest dreams would have thought a couple of years ago (i.e. before the landings) that we'd be looking at such clear images of amazing rock formations like these. And that we can look "over the scientists' shoulders" as it were, downloading the latest images as they arrive from Mars.

Thank you NASA/JPL/Cornell!

Something I've been looking for (but have not seen clear evidence for lately) is the ripple marks as seen in Eagle Crater. Perhaps we need MI images to see those better, but the layering in these images looks pretty coarse, which would indicate a different sedimentation environment I suppose.

I wonder too if the undulations on the top right of Bill's first image are indications of ripples, or just the way it looks after the rock has worn away at a shallow angle across regular laminations?

Airbag

Bill,

the shape of the depression has changed between your two images !



Rakhir

And here I was thinking that nothing ever changed on Mars!

That changing pattern in the sand is very weird. The lighting is similar and although the viewing angle is slightly different but I can't see any way to explain the transformation from one clearly defined subsidance\imprint pattern to the other.

Explanations anyone?

Nice catch Rakhir! I don't think this was changing lighting conditions either. Wind perhaps?

The full initial shape of the "depression" can be seen in this Sol 652 pancam
The shape change was observed after 9 Sols, in Sol 661, so there is plenty of time inbetween for wind, rover motion shaking the outcrop, or whatever...

I suspect settling of fine dust by shaking will be the answer but the outline and bottom of the depression seem a bit too neat (in both senses of the word)

Reckless

The bunnies did it.

It looked fairly solid in the raw images but it looks more like a pile in the images at Cornell's pancam image site
http://marswatch.astro.cornell.edu/pancam_..._1_True_RAD.jpg