Pot of Gold at Methusilah?

Here are a couple of stereo pairs that show little stem-like protrusions assosiated with some of the layers at Methusilah. These are reminiscent of what we saw at Pot of Gold. If Methusilah contains hematite like Pot of Gold it could explain the rusty "soil" that covers Methusilah and Larry's Lookout.

What implications would hematite have if it is found in this layered rock, as hematite implies the presence of water at some point? Steam during a volcaniclastic explosion? Standing water covering airfall deposit or aeolian deposit?

Left:

Right:

remember Squyres commenting on how the rocks examined appear to be altered by water in the CH ? The phosphate, that was likely secondary along with the hematite. My guess would be a former geothermal area, maybe buried, now exhumed by whatever process caused the tilting of the beds.

Aldo, Thanks for that. I see the strong similarity between Methusilah and Pot-O-Gold, which means that I am probably wrong about Pot-O-Gold being a growth form. It is more likely an erosion form.

In your image, to the far right, pebbles are visible just emerging from soil. Is the presence of these pebbles somehow being caused by the erosion of Methusilah? Were these pebbles once connected to the ends of protuberences like those visible elsewhere in the image? Are they still connected but beneath the soil? Why are these pebbles spaced apart?

Kye, how about this? If we speculate that this might be a volcaniclastic with millimetre and centimetre sized fragments, the "protrusions" could represent wind tails forming behind the fragments, similar to how stems formed behind spherules at Meridiani. Eventually, the fragments would be completely eroded from the outcrop and could represent a substantial portion of the pebbles you're referring to.

Aldo, Thanks, that is a pretty complete hypothesis. How about the "spaced apart" distribution of those pebbles? Here is a better example, I think also from Methusilah. If the many small pebbles just visible at the soil surface are erosion fragments how do they end up distributed in this way? We do not often see anything that looks like talus, a pile of fragments that have broken off and rolled together at the base of a slope. Instead we see this strange pattern of particles, just one deep and spread out uniformly across the surface. Freeze-thaw cycles on Earth can rearrange rocks in soil. Any theories, or am I seeing a non-phenomenom?

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I see what you mean, Kye. Also interesting is that the "density/frequency" of pebbles/fragments seems to decrease with distance away from the outcrop. It also seems that the pebble size increases with distance away from the outcrop. Notice the change along the bottom of the photo.

Could this simply be a lag left over and sorted by wind erosion, the smaller pebbles neareast the outcrop being the most recently removed?

Aldo, Yes, thanks, the spacing pattern seems real alright and the size gradation. Here are a couple more examples of what looks like the spacing apart of particles in soil. This sort of thing is very common at Gusev once you look for it, at different scales and not always associated with rocks like Methusilah.
Wind sorts particles by size but the various sizes tend to end up piled together, not evenly distributed through finer material. I would have to guess that the larger particles start out in random positions and are then somehow moved away from each other until they are evenly spaced. Could their higher thermal inertia compared with the finer soil matrix somehow bias the effect of freeze-thaw cycles in a way that slowly pushes them apart? I am pretty sure that we do not know enough about water in Mars soil to answer that question.

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L257 2x8 panorama (109 degrees) of Methuselah area:

80% 1/2 size JPG version (1.4 MB)

80% full size JPG version (4.6 MB)

If there are any areas you would like as L257R12 images let me know.

Horton, Thanks for that image. Its a beauty and useful too.

MI 4x4 Pan (1/2 size):

Pan created by AutoStitch

MI 4x4 Pan Location:

3D MI of area:

Now, exactly what kind of rock is this?

Looks like the frosted flakes form endurance to me.

I don't see any vug-like formations, and neither is there signs of blueberries, so it seems a little different from the Meridiani rocks, but does resemble an evaporite deposit.

Is there still a chance that this could be a welded tuff of somekind, or some other explanation that does not involve a Gusev sea? Way to go Spirit!

Awesome mosaics, Horton!

It seems we're looking at textures and features previously observed at "Pot Of Gold":

and "Tetyl"

I think an airfall tuff is definitely in the running. The only question is the how were the rocks altered.

I should've said the one big question is how the rocks were altered. There are lots of questions. Figuring out the structural geolgy of the Hills, for instance, is going to be very challenging.

Is it possible that Tetl and the other layered outcrops at West Spur are downdip extensions of Methusilah?

CHEMICAL WEATHERING.

Hi,

I've just posted my colorised composite images using the colors from the following images [probably shooted for this purpose ]

2P168091386EFFA9I4P2561L6M1.JPG
2P168091363EFFA9I4P2561L5M1.JPG
2P168091330EFFA9I4P2561L4M1.JPG

It's here (1Mo)

more images using this technique are at Ethnotronics.com/Mars

ERic de Paris

More MI 2x4 Pan (1/2 size) of reply 9:

Pan created by AutoStitch

This is a continuation of the pan in reply 9 on the right. I tried adding it to that pan, but the result was not pleasing.

OK, the numerous projections in the lower right are very, very much like those on Pot'o'Gold.

It will not surprise me that the chemical composition of this rock is exactly the same as Pot'o'Gold.

Super 3D L257L257 of current target rock:

Notice all the little stalks with pot'o'gold berries.

here is the link to the image that the comment parser ate in reply 17.

Come-on! fix it!

Say, are all you rock guys in Philadelphia today?

Try

http://www.lipfordm.com/wtsi/sp-2P167559742EFFA9HEP2280L257-2-2P168178721EFFA9I4P2563L257.png

Sheesh.

Nice work, Horton.

What's interesting about the Pot of Gold-like projections in the bottom of the reply 16 image, is that the tips of the projections are often flat with somewhat of a platey form.

And, yeah, I agree, odds are that this outcrop is going to be high in hematite.