Rovers on Mars

The low angle cross bedding that rosborne showed us a day or so ago has, if it can be verified by closer inspection and computer imaging, the potential for being a really important find cuz low angle cross bedding is an indicator and , if the pebble sizes can be measured, a velocity tool for hydraulics. Not only a body of water , but a moving stream.

Im leaning more to ash falls into water(tuff) and the formation of small chert(silica and other cations in the lattice ) concretions that are more indicative of thin sed layers overlying a basement rock of earlier formation.

Flaky "Mimi", the image of which was taken by the Spirit rover, seems similar to rocks often found in old volcano areas on the Earth.

Look, Dirt. (A picture only a geologist could love )

This is a picture of the dirt in the trench recently dug by the wheel of Opportunity Rover. Hopefully the Spectrometer results will be more revealing.

A picture of the photographer

They say rover may be rolling in mud. Whatever it is is sticking to the wheels.

The Spherules at Meridiani Planum are buried in the dirt as well as on the surface, and the ones that are buried have a glossy aspect to them, in contrast to the exposed ones which seem to be more dull (probably weathered).



I'm still guessing Tektites. With all the impact craters on Mars, the whole planet must be rolling in tektites

For what it is worth, that looks like mud to me.

Mud implies water, and that would be spectacular. So I hope you're right

Are we ever going to see "true color" pictures of those spherules? Is the microscopic imager capable of taking color images, or is it just the Pan-Cam which can do color?

After soil studies, Opportunity would move to the bedrock outcrop next day or later. I am expecting studies of the bedrock, which is more intriguing for me.

I've been trying to remember where I've seen this "smoothness" in the rock face before. It reminded me of something I've seen before, and now I remember; many of the rock formations I've seen in caves have this "melted" look to them. But none that I remember have this level of granularity in the surface.

It's a very odd combination of attributes: Polished looking, but with small granularity and lots of crevases in the surface. These "slices" and "convolutions" and "holes" in the rockface don't make any sense to me. I've never seen an analogous structure before.

And here's a little document on Metamorphic rock in case anyone is interested: http://seis.natsci.csulb.edu/bperry/ROCKS.htm

It is an interesting and educational link.
However metamorphic rocks are formed when the original rocks are buried deep underground often with heat nearby. I hardly think rocks seen through cameras on the two rovers on Mars can be metamorphic.

Why do you think they can't be metamorphic?

Do we know enough yet to conclude that they didn't form under such conditions?

Don't get me wrong, I hope they are sedimentary too, but it's clear from the Gneiss in the image above that metamorphic rock can have layered banding which appears similar to sedimentary.

All in all, I find the Mars images perplexing. They don't seem to fit any consistent pattern of formation which we've seen before. And I'm not complaining or anything, after all, we did go to Mars to discover new things, and this really great stuff

Why I hardly think those rocks now found on Mars are metamorphic?
Usually metamorphic rocks on Earth are found in areas more complicated such as mountaineous regions resulted through tectonic motion of the crust. The areas where the two rovers have landed were chosen to be those as plain as possible.
(Of course Mars is different from Earth, and it is not wrong to have knowledge about metamorphic rocks.)

I think that's Janet Jackson's boob at left in Rosborne's 4:43 post 574580 above.

I said one saw what one wanted to see here.

Boy, Ive missed some new pics. The pic that rosborne posted last is very unusual. On earth , we have minerals in rocks that are chemically weathered and then replaced by a later mineral. Those empty plates in the rock surface and the shiny surfaces looks like that to me. They call these "pseudomorphs" One type of mineral precipitates in the place of another. Its either that or , and I dont say thsi with any conviction, it could be fossil traces called ichnofossils, which are the left over holes from shell casts that have weathered out.

The only metamorphics that seem probable is 'shock /dynamic metamorphism" wherein a meteor hits the original crust and shifts the whole crystal structure of the rock mass and shocks it all into another xl system. its possible but I dont see any indicators , like a strong banding of color . In this outcrop the banding appears to be differential weathering as in rock layers withh differing erosion or solubility strengths.

But it does look like fossil shell casts, wouldnt that be something? if you look carefully at the "cast" on the bottom right of rosbornes pic, it looks like a Tube, worms build tubes. Of course it could be tracks from AA lava, but Ive never seen a white lava

The spherical in Rosborne's pic has a small nob. Those spurs sometimes occur when a hot liquid material is dropped into water.

They also occur in tektites which form in the air.

In another image (which I haven't posted yet), one of the spherules appears to have a smaller spherule welded into it, as though they merged during formation. I'll try to find the pic. ... I can't find it. Maybe I imagined it... bummer, I hate it when that happens.

Farmerman, even before I read your post I was googling for images of fossil reef remnants (still digging into my memory to find anything which looks like those images). Along the way, I ran into this: http://www.cretaceousfossils.com/plants/porocystis_globularis.htm