Elongated Crater on Mars

[astroron]

An interestingly shaped crater on Mars gets the Geologists thinking:question:
http://www.esa.int/SPECIALS/Mars_Express/SEMDV9BO3DG_0.html
Cheers

[renormalised]

Very interesting....might have a crack at summising how it formed:)

After breakkie though::)

I'll have a good look at the pics....maybe a few days, yet before I can come back to this. Have to finish off my assignment. However, I can say this...the fault graben cutting across the rim of the depression....they're definitely later than the crustal extension that created the depression. They cut right across it....see the large one about halfway along the depression, if you look closely you can see a faint extension of the graben that's pretty much covered by the infill (which is mostly a basaltic plain and sediments). You can tell by the slight differences in colour and the impression of the underlying geology showing itself at the surface...it can't be buried too deeply. It's a very complex geology...it won't be solved overnight, that I can assure you. This is precisely why we need to send people there, to ground truth what we find from the probes and to drill this thing to bits...get a handle on it by core logging the rock formations (at depth) from the drill cores, map the place at high scale, sample the rocks and thin section them....the works. Just staring down at them from 800km up isn't going to figure things out.

[DavidU]

Very interesting Ron.It seems to have formed at 90deg to the surface faults.
Carl?

[renormalised]

The depression is a lot earlier than they are. It would've had to form, partially infill then several series of graben came along, and then they were filled to partially filled, again. Then you have later extension and then compression. All the while there's been craters forming....some are older than the E/W trending graben, they're cut by the graben. Others are younger, they cut the graben off. If you look in the middle of the plain, you'll see two NW/SE tending gashes, only small. They're graben but they've failed to develop anymore than as a short gash through the plain. I'd say they're formed through a slight adjustment of the basement rocks in the area, nothing more than a jostle...you can see one of the earlier E/W graben (a small one) has part of its valley slightly displaced along the trend of those graben I've just mentioned...it's been faulted in that direction.

[astroron]

Carl, I posted this just for you;) it is great to read your interpretations :thumbsup:
If I was better educated I would have loved to be a geologist:), instead I finished up being a soldier:(

[kingkong01]

looks tho as it has been struck by something going almost horizontal or as it says erosion of aligned impact craters over time... thats just my two cents worth tho

[renormalised]

Nothing wrong with being a soldier, I was one (a reservist) before I graduated from uni. I think if some of today's kids spent some time in the services, it'd straighten quite a few of them out, teach them some discipline and maybe give them a good profession for life, if they decided to stay in.

[renormalised]

It's a very complicated geology, one that's not going to be solved by purely remote sensing. It needs ground truthing...like any good geologist would do.