South Endeavour Crater - Page 13

Previous 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13
Author Message
Barsoomer


Posts: 344

Reply: 241



PostPosted: February 1, 2018 11:03 PM 

Towards bottom: odd-looking rock seemingly hugging another rock.

Looks to me like the water froze here (and then sublimated).

[link]

TPS Monthly Update for January by A.J.Rayl.

Barsoomer


Posts: 344

Reply: 242



PostPosted: February 2, 2018 11:42 PM 

This illustrates one of the points in the monthly update from The Planetary Society. The regolith is gradually moving downhill in Perseverance Valley and tends to pile up against existing outcrop. Note how light the sun-exposed outcrop is compared to loose dark rocks from under the regolith.

I think this makes a nice postcard image: a beached rock by the side of the dried river bed.

Barsoomer


Posts: 344

Reply: 243



PostPosted: February 4, 2018 9:14 PM 

Rocks with dome-like shapes in an area once filled with water, but a rough texture. Stromatolites later covered with gravel, perhaps?

Grey and whitish areas of rock indicating a previous waterline? Note the areas below the putative waterline are more pitted than the areas above---not what would be expected if the pits were due to windblown dust.

LWS


Posts: xxx

Reply: 244



PostPosted: February 5, 2018 5:31 AM 

Barsoomer;

Nice illustrations and inferences!

Keep them coming

Winston

Barsoomer


Posts: 344

Reply: 245



PostPosted: February 10, 2018 9:48 PM 

New MIs. Bright coating over dark rock, seems cohesive. Note the small grains in the crack to the right. Resolved here, I think they are what composes the fine-grained dark semi-transparent sand we see in microchannels.

Those fine dark particles may be "budding" out of the dark rock face seen here.

John Radogno


Posts: 37

Reply: 246



PostPosted: February 11, 2018 12:05 PM 

It could be evidence that the layered material is composed of concretions and the budding material is more resistant to weathering by the winds.

Barsoomer


Posts: 344

Reply: 247



PostPosted: February 14, 2018 12:43 AM 

Dark sand flowing over and carving chasms in the rock.

Odd surface on this rock. Right/left/right image set can be viewed in cross-eye or parallel-eye stereo.

Barsoomer


Posts: 344

Reply: 248



PostPosted: February 15, 2018 10:51 PM 

MER team took a pancam closeup. Still an interesting surface.

Some odd stuff littering the floor of Perseverance Valley.

Martian trash heap? Holey twisted rocks here. Volcanic? Or an ancient coral-like substance?

We seem to have reached the interesting part of the valley...

John Radogno


Posts: xxx

Reply: 249



PostPosted: February 16, 2018 11:00 AM 

Looks a bit like the surface was pushed up from some below ground force.

Barsoomer


Posts: 344

Reply: 250



PostPosted: February 17, 2018 1:44 AM 

Part of the former "sea" floor. Denizens of the deep.

Barsoomer


Posts: 344

Reply: 251



PostPosted: February 17, 2018 2:28 AM 

I forgot to mention: Look closely at the surface of those rocks. There seems to be a rectilineal pattern rather like the fabric of a piece of clothing.

LWS


Posts: xxx

Reply: 252



PostPosted: February 17, 2018 7:17 AM 

Barsoomer; re your reply 251;

I see the pattern you alluded to and my first thought was that it might be an artifact of the image processing process but on second thought that seems unlikely as the pattern appears to be draped over the eroded surfaces of the rocks. Could it be remnants of a microbial mat?

Winston

Barsoomer


Posts: 344

Reply: 253



PostPosted: February 17, 2018 8:38 PM 

I would love if that were so. I suppose a mundane explanation might be that these are "gravel balls" formed by multitudes of similar-sized pebbles sticking together to form rocks. Not sure what the cementing agent would be.

Barsoomer


Posts: 344

Reply: 254



PostPosted: February 20, 2018 10:48 PM 

The rectangular on many of the rocks seem to be due to spherical bumps on the rocks that are arranged in somewhat regular patterns. Some other rocks seem to have more elongated bumps in more chaotic patterns.

The smaller rocks in the foreground appear to have cavities that more or less match the bumps.

It seems plausible to me that some of the rocks here are mineralized microbial mats, noting their bent and upturned shapes. A lot of repetition in the shapes in this area.

LWS


Posts: xxx

Reply: 255



PostPosted: February 21, 2018 7:53 AM 

Barsoomer;

Sounds reasonable to me!

Winston

Barsoomer


Posts: 344

Reply: 256



PostPosted: February 22, 2018 12:01 AM 

This shows the "bumps" on the rocks more clearly.

I had to use parallel-eye stereo---the details do not show up as well in cross-eye.

Note the flat rock near the top that has a triangular cross-section; it seems to have a coating of "bumpish" material rather than the material being part of the rock. Also note the pebbly material in the microchannel. This leads me to hypothesize that the pebbly material was carried along by the microchannel and flowed over the rocks, coating them and possibly also altering them in some way.

Except that I do not think the "pebbles" were pebbles. Note the more whitish rock near the top but below the traingle rock. It looks like some gooey material with more solid inclusions coated that rock.

Context image:

link

Barsoomer


Posts: 344

Reply: 257



PostPosted: February 26, 2018 10:04 PM 

What is this stuff? Any ideas? Twisted pieces of metal? Fossilized coral? Meteorite fragments? What?

Barsoomer


Posts: 344

Reply: 258



PostPosted: February 26, 2018 10:53 PM 

My guess: remnants of rocks that have been mostly consumed by lithotrophic bacteria. The dark soil is the waste product left after the consumption, and possibly contains concentrations of the bacteria. Notice the dark soil is heaped on top of the perforated rocks in places.

https://en.wikipedia.org/wiki/Lithotroph

John Radogno


Posts: xxx

Reply: 259



PostPosted: February 27, 2018 2:02 PM 

Very interesting. Thanks for thr wiki link!

Barsoomer


Posts: 344

Reply: 260



PostPosted: February 28, 2018 11:12 PM 

Notice the whitish sheetlike rocks that seem to form a "ceiling" over the dark rocks. Also note the interplay of white, brown, and dark blue (false) colors in this area.

Previous 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13


Join the conversation:















Very Happy Smile Sad Surprised
Shocked Confused Cool Laughing
Mad Razz Embarassed Crying or Very Sad
Evil or Very Mad Twisted Evil Rolling Eyes Wink
Powered by MTSmileys