Meridiani outcrop

hrtbreak wrote:

Would one expect to see carbonates fixed in rocks when the atmosphere is
rich in CO2? Doesn't the large-scale fixation of CO2 in our atmosphere into
rock formations require living organisms, like diatoms?

Not to criticize your other speculations, but diatoms secrete
siliceous tests, not carbonate. There are other critters, of
course, that DO turn CO2 into CO3 in rocks.


Assuming the stuff
we're looking at is built from layers of wind or water borne material, what
process converted it into rock? If it had to be under extreme pressure from
overlying layers to become rock, how would you get vertical movement of the
bedrock toward the surface without tectonic plates? Could you get this kind
of striation with many inundations of low-viscosity lava, for example?


We don't really know how consolidated it is - it may not have had
to be under "extreme" pressure. On earth sediments lithify with
proper cement and not too much pressure. As for the tilting,
maybe by the impact process that formed the crater. Given the
small scale of the outcrop (about 4" they say), those would be
VERY thin lava flows. Possible, yes; probable - ?


Yes, I'm an engineer, but I didn't have anything better to do at the moment.


JJ Robinson II
Houston, TX
****************
* JOKE *
****************
* SERIOUS? *
****************
* SARCASTIC *
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* OTHER? *
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--
_____________________________________
Richard I. Gibson, Gibson Consulting
Gravity-Magnetic-Geologic Interpretations
http://www.gravmag.com

301 N. Crystal Street
Butte, Montana 59701 USA
Phone/Fax (406) 723-9639

Education Director, World Museum of Mining
http://www.miningmuseum.org

Kurt Spunkle wrote:
You've all got it wrong. Look at the panorama shot:

http://marsrovers.jpl.nasa.gov/galle...B003R1_br2.jpg


Start at the right side of the image and move to the left. It's a fossil!
You can clearly see the tail bones and vertebrae, as well as various belly
scales and what might be limb bones!

NASA can't cover it up much longer. There is life on Mars, probably living
in underground lakes and oceans! These fossils prove it!

Kurt



oh foo, you beat me to it! LOL


- nate

hrtbreak wrote:

Doesn't the large-scale fixation of CO2 in our atmosphere into
rock formations require living organisms, like diatoms?

No. Organisms can cause carbonate formation at lower CO2
concentation, or at a faster rate, but enough CO2 and carbonate
will form by itself.

Don't diatoms have silica skeletons?

Paul

"Nate Smith" wrote in message
...
Kurt Spunkle wrote:
You've all got it wrong. Look at the panorama shot:


http://marsrovers.jpl.nasa.gov/galle...B003R1_br2.jpg


Start at the right side of the image and move to the left. It's a
fossil!
You can clearly see the tail bones and vertebrae, as well as various
belly
scales and what might be limb bones!

NASA can't cover it up much longer. There is life on Mars, probably
living
in underground lakes and oceans! These fossils prove it!

Kurt



oh foo, you beat me to it! LOL



Anyone up for a fishing trip?

"Richard I. Gibson" wrote in
message ...
hrtbreak wrote:

Would one expect to see carbonates fixed in rocks when the atmosphere is
rich in CO2? Doesn't the large-scale fixation of CO2 in our atmosphere
into
rock formations require living organisms, like diatoms?

Not to criticize your other speculations, but diatoms secrete
siliceous tests, not carbonate. There are other critters, of
course, that DO turn CO2 into CO3 in rocks.
---clip---
See speculation qualifications below. My point was that if there were
carbonate-based rocks in large quantities, would there be all that free CO2
left in the atmosphere? We don't really know enough to guess what the
environmental cycles on this alien planet are like, but I had to start my
baseless speculations somewhere. Then again, there wouldn't be evidence of
"large quantities", either.

We don't really know how consolidated it is - it may not have had
to be under "extreme" pressure. On earth sediments lithify with
proper cement and not too much pressure. As for the tilting,
maybe by the impact process that formed the crater. Given the
small scale of the outcrop (about 4" they say), those would be
VERY thin lava flows. Possible, yes; probable - ?

When I wrote this, I think they were saying the formation was about a
foot-and-a-half tall. The weird soil mechanics seen around the landers
might be a factor in the formation process, too, I suppose.

Yes, I'm an engineer, but I didn't have anything better to do at the
moment.


JJ Robinson II
Houston, TX
****************
* JOKE *
****************
* SERIOUS? *
****************
* SARCASTIC *
****************
* OTHER? *
****************




--
_____________________________________
Richard I. Gibson, Gibson Consulting
Gravity-Magnetic-Geologic Interpretations
http://www.gravmag.com

301 N. Crystal Street
Butte, Montana 59701 USA
Phone/Fax (406) 723-9639

Education Director, World Museum of Mining
http://www.miningmuseum.org

mlm wrote in message ...
Timothy Demko wrote in
:

mlm wrote:
Timothy Demko wrote

My first impression of the much-talked-about Meridiani outcrop is
that it looks like a fractured, platey basalt flow, maybe even
pahoehoe. In the upper right hand corner of the PanCam image, right

Well, today's (1/27) briefing was very enlightening! The new PanCam
images definitely show fine-scale lamination, and the rest of the
panorama shows some very nice trough cross-bedding/cross-lamination!
I'm suprised that they had Andy Knoll (a paleontologist) did the
briefing, rather than John Groetzinger (a sedimentologist). Andy did a
great job, though, of explaining the significance of cross bedding.

http://marsrovers.jpl.nasa.gov/galle...20040127a.html


nicely layered, with flexural drag fold in the extreme right of the
image with axial fracture cleavage/ jointing. (middle scale image).
"Cross bedding" is drawing the longbow.

"Joe Knapp" wrote in newsY_Rb.34876$P%1.27467009
@newssvr28.news.prodigy.com:

http://www.copperas.com/astro/bedrock_rgb.jpg

THanks for the photo. It does look a lot more realistic and the final
color corrected photos of the site will probably be closer to your image
than the ones recently released by JPL. They are way too red.

Mark

"hrtbreak" writes:

"Richard I. Gibson" wrote in
message ...
hrtbreak wrote:

Would one expect to see carbonates fixed in rocks when the atmosphere
is rich in CO2? Doesn't the large-scale fixation of CO2 in our
atmosphere into rock formations require living organisms, like diatoms?

Not to criticize your other speculations, but diatoms secrete
siliceous tests, not carbonate. There are other critters, of
course, that DO turn CO2 into CO3 in rocks.
---clip---
See speculation qualifications below. My point was that if there were
carbonate-based rocks in large quantities, would there be all that free CO2
left in the atmosphere?

If Earth-life hadn't happened to accidentally stumble across the trick
of spewing out the nasty toxic poison waste-product gas called "oxygen,"
Earth's atmosphere would still have even _MORE_ CO2 in it than Mars's ---
and it took earth-life over a billion years for it to stumble across
_that_ particular trick!



-- Gordon D. Pusch

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Gordon D. Pusch wrote:

If Earth-life hadn't happened to accidentally stumble across the trick
of spewing out the nasty toxic poison waste-product gas called "oxygen,"
Earth's atmosphere would still have even _MORE_ CO2 in it than Mars's ---

Why? Most of Earth's carbon is fixed in carbonates, not organic materials,
right? The presence of large amounts of liquid water on Earth causes CO2 to
react more quickly with positive ions from weathered silicates.

Paul

"Paul F. Dietz" writes:

Gordon D. Pusch wrote:

If Earth-life hadn't happened to accidentally stumble across the trick
of spewing out the nasty toxic poison waste-product gas called "oxygen,"
Earth's atmosphere would still have even _MORE_ CO2 in it than Mars's ---

Why? Most of Earth's carbon is fixed in carbonates, not organic materials,
right? The presence of large amounts of liquid water on Earth causes CO2 to
react more quickly with positive ions from weathered silicates.

Yes, but that reaction had already proceeded to equilibrium before life evolved.

Remember that the carbon in carbonate rock is constantly being recycled
back into the atmosphere by volcanic activity, and that essentially all the
O2 in the atmosphere is the result of chlorophyll-based photosynthetic life,
constantly replacing one molecule of atmospheric CO2 with a molecule of O2.
Without chlorophyll-based photosynthetic life, there would be essentially
no free O2 in the atmosphere, and instead there would be the same order
of magnitude number of CO2 molecules (modulo concentration shifts in the
atmosphere/ocean CO2 equilibrium point).


-- Gordon D. Pusch

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