New Rover Spies Layered Rocks on Mars

AP ^ | 31 minutes ago | ANDREW BRIDGES

[doodad]

I am a geologist and can tell you that many different activities can cause a "layered" appearence. My first thought when I saw the picture was metamorpic rock which has been compressed and folded, which would account for the "bent" look to the layers. Metamorphism can cause VERY fine cleavage to form (think slate and pool tables) depending on the host sediment and the temp/press of the event. Did I say sediment? Yes, but given the area is largely hematite and known to be an area of volcanism, I would guess that what we are seeing is exhalative ash deposits which have then been subjected to light metamorpism which would account for the layering of the ash dust as it settled in different deposits and the folding during metamorphism. JMHO.

[LibWhacker]

Yep. And when you think of all the flybys and how riveting they were . . . Tough call. Feel sorry for people who don't have a sense of wonder and who don't feel at least a little pride in what we're doing.

[JoJo Gunn]

What's wrong with all you guys? Lookit the far right. It's dinosaur bones.

[LibWhacker]

Another article I read said that layering caused by volcanism tends to be very uniform, while that caused by sedimentation tends not to be. Do you think we can tell anything from the lack of uniformity in the layers here? Or are they uniform enough to be consistent with, what, volcanic ash deposits? Just trying to jump the gun. :-)

[maestro]

Where are the pictures of the 'Junkyard' they found on Mars the other day?

:-)

[Professional Engineer]

Can't wait for Opportunity to roll off the lander and go over there!

You and me both!

[Muleteam1]

>>Fascinating.<<

Fascinating indeed! Although I'm sure my ability to be fascinated has been dulled by my middle-age, I find this Mars exploration as fascinating as the first moon landing (Ranger 7) when I witnessed it as a ninth grader. It is my opinion that, before mediocrity completely overwhelms our society, we again return to space and the fascination and hope it offers humankind.

Muleteam1

[Muleteam1]

>>light metamorpism<<

Doodad, in your judgement what forces could cause the metamorphism in the ash?

Muleteam1

[billorites]

I've been fascinated with space since first grade when we all went to the lunch room to watch the Alan Shepard suborbital flight.

I must admit that very little has "wowed" me in terms of manned flight since the early shuttle flights.

I think robots is where the future is.

[Salamander]

[doodad]

Another article I read said that layering caused by volcanism tends to be very uniform, while that caused by sedimentation tends not to be.

Sedimentation is rarely uniform regardless of whether the sediments are airborne, streamborne, or various kinds of flows (lava, mud, etc). When it is you have to suspect either short time events or closed area (like a lake). The subject area may have been metamorphosed by an impact alone, but my suspicions were raised by the angle that the foliation (sticking to my hypothesis for now versus fluid sediment) of the rock changes in such a small area from an angle of say 30* on the right to near horizontal in the center. Very possible with metamorphosm, but straight up sedimentation would be flat, course.

Now, what would be cool would be ash deposited in a viscous form implying surface water, and then folding!

[doodad]

Doodad, in your judgement what forces could cause the metamorphism in the ash?

Either the impact from something (which can be checked be looking for shatter type fracturing) or the proximity to a plate edge. Just like here and evidenced by the volcanism.

[JoJo Gunn]

[Muleteam1]

I was just informed in another thread that Mars is believed not to be tectonic in nature but I'm not sure if this theory pertains to early Martian geology. I can clearly see the possibility of impact metamorphasis and fracturing though.

Muleteam1

[John H K]

Mars is generally believed to not have experienced earth-like plate tectonics.

[doodad]

Mars is generally believed to not have experienced earth-like plate tectonics

I hadn't heard that(don't follow the astro stuff as much as terrestrial), but volcanism certainly points to some kind of fluid transfer from the interior of the planet to the surface and the deformation at the area. I guess we will find out.

[Conspiracy Guy]

That wasn't a junkyard, that was my front yard. Tis is so fake.

CG

[John H K]

There are some really large-scale bulges in the volcanic areas (causing faulting, etc.) but no evidence of plates sliding around.

[BenLurkin]

[Salamander]

;))