On the Road Again - volume 4 - Page 3

"a bundle of parts". A good wish, and give Spirit a good tug.

[quote=hort]
Rock guys, I'm not just picking on you. I know it ain't science to say "I don't know" - but at least give hints of the form "If this were an observation on the Earth then the possible identifications in decreasing probability are..."
[/quote]

OK, "it's a rock".

Seriously, Marquette is unique because, based on it's crystal structure and it's apparent minerology it seems to be the first rock we've seen that is an igneous intrusive rock, emplaced within the crust or upper mantle at depth. This coarse-grained rock is called a gabbro and has the same composition as the extrusive ("lava") rock basalt. Likely, it is a sample of the deeper crust or upper mantle that was excavated during a large impact event and was emplaced here as ejecta.

This mantle rock-- called, generally, a peridotite-- is readily altered ("weathered") in the presence of water to other minerals, in the serpentine family, in a process called serpentization.

Finding serpentine in this rock could be the Holy Grail of Martian geology-- proof of water, liquid and in quantity.

This website on the "Lost City" area of the mid-Atlantic Ridge has good information on serpentization:

[link]

Otherwise, Google is your friend.

--Bill

Hi Serpens

You asked LWS " Is there any way that a fungus could flourish in this environment? "

The short answer is; I don't know.

But do you know if there is a way that Oppy's instruments (and what instruments from other spacecraft have shown over the years about habitability as viewed from an earth perspective) can definitively disprove that the textures on some cobbles might be due to some organism or groups of organisms that have evolved over eons in a totally different environment to earth?

Given what we think we know about Mar's environment it seems most unlikely that these textures could be biological in origin. But we really have only skimmed the surface in our knowledge of Mars. There are still many unanswered questions that relate to this. Some of these questions are;

What really are the methane sources on Mars?
What did Levin's viking experiments really find?
How accurate were the instruments that indicated absence of organic materials on the surface of mars?
What about a possible hydrological cycle on Mars that might include a liquid water phase?
What might be the role of perchlorates in the water economy of Mars as well as the question of absence of organic materials?
Are organic materials really absent or might it be that the instruments we have used in the past were incapable of accurately assessing the presence of such materials?
Do we know everything there is to know about putative microbial life that might have evolved over eons in harsh environments such as mars if we only use the limited lens of our earth experiences to pontificate on the absence of such life, especially since the research of the last decade or so seems to be suggesting that at least on Earth life adapts to survive in the harshest of environments?

I don't know, but imho, the scientists who are so sure that there is no life at or near the surface of mars don't know either and should temper their conclusions on this matter until they can definitively say there are no organics on the surface of mars or at least meridiani and there has been no liquid water for eons on the surface of mars or at least meridiani.

Winston

Hi Serpens

As a follow up to my #43 above, I went looking for any recent Gil Levin paper and found the one below;

http://gillevin.com/Mars/SPIE-2009/SPIE_Paper_2009_as_Pub.pdf

http://gillevin.com/Mars/SPIE-2009/SPIE_Paper_2009_as_Pub.pdf

It has some good (imho) arguments about the possibility of life at or near the surface of Mars. If there is any validity to these arguments there may also be some validity to the possibility of some of those meridiani cobble surfaces exhibiting signs of anaerobic microbes that may be involved in the production of Methane. We will have to await a non-geology focused lander/rover to get some definitive answers to the current unknowns.

Winston

...Finding serpentine in this rock could be the Holy Grail of Martian geology-- proof of water, liquid and in quantity.

Yay!

Let's all hope Marquette is indeed serpentine.

Lots of water for lots of time and lots of chemistry equals...

Er, Exactly what is the serpentization mechanism that weathers the rock? What is the geochemistry?

Is it a simple chemical reaction

H2O + rock -> serpentine + other stuff

OR is the reaction catalyzed by, say, complex self-contained chemical systems in disequilibrium with the environment?

Lets start with a simpler question:

Why does the Martian "orange" soil turn "red" when run over?

PS--

Serpentinization can also be a non-biologic source of methane.

Olivine + Water + Carbonic acid → Serpentine + Magnetite + Methane

--Bill

Hort asks:

Er, Exactly what is the serpentization mechanism that weathers the rock? What is the geochemistry?
Is it a simple chemical reaction
H2O + rock -> serpentine + other stuff

In a nutshell, that's it. A "mantle rock" (ie, the interior of a planet) is composed of olivine/pyroxene/peridotite, a "gabbro" and it inherently reacts with water and produces serpentine, magentite (an iron oxide), silica, heat, hydrogen, methane and a host of other mineral byproducts depending on the trace minerals in the rock.

Here are a couple of refs:

That "Lost City Massif" website chemistry page:

http://www.lostcity.washington.edu/science/ch
emistry.html

A Wikipedia page on serpentization:

http://en.wikipedia.org/wiki/Serpentinite

I've found a lot of super-tech, geeky siyes on this, let me keep digging for some "Geochem 101" sites...

--Bill

Bill Harris, thanks for the serpentization links.

So, what are the lab measured reaction times?

If I drop a 1 meter block of olivine into a large tank of pure water how many years does it take to become serpentine?

Are there catalyst that speed up the process?

( I could google this myself but then who would create the next color by horticolor image? )

I'm not sure-- by a geological timeframe it is quick and inevitable. By a human timeframe it is eventual. I've not seen a time reference, but I'll dig around.

One thing is that fractures help the reaction a lot by allowing water to penetrate the rock mass. Such as fractured and faulted along a mid-ocean rift. With a solid block, it will weather on the outside but stay pristine on the inside. That is why folks got so giddy when the first brushing showed what looked like a mineral-filled fracture.

Meanwhile, we ought to fidget over the RAT. That last grind on Marquette doesn't look right. Oppy looking at her RAT with the Fwd Hazcam is worrisome.

--Bill

Opportunity thrashes nearby ripple. Rover vandalism!

Hort; your reply 45,
Could the circumstance that turned the soil red, be the same one that turned the "white color marker" red also .

Info I have gleaned about Mars indicates the crust ranges from 35 km in the north to 80 km thick in the southern hemisphere where the huge impact crater Hellis Planitia is only 6km deep.
This leaves the bottom about 70 km above igneous rock in the mantle.

The point I am trying to make is that if Marquette is mantle rock (gabbro), how did a chunk of it end up on the plains of Meridiani?

There has been no late tectonic activity that would have brought it to the surface and the basalt from the latest vulcanism is a different composition.

Eh, maybe "mantle" is a bit of an exaggeration. Given that Mars' crust appears to be mostly "mafic ocean basin" rocks, with precious few granitic crustal plates, a gabbro could fit in there. Or if not a true mantle peridotite, it could be from an intrusive mantle plume that cooled slowly. There is ample basaltic extrusive activity nearby in the Syrtis and Tharsis regions (remember, the main difference between a basalt and a gabbro is the cooling rate, intrusive or extrusive) and there are a number of large impacts without getting into the Hellas-Argyre types that could have tossed ejecta this far. It's not too much a leap of faith to find this rock here at Meridiani.

--Bill

Oh, listen to the science.

Horts plea is a plea that has been posted on this forum many times. It will be posted again. Why? We can reach no conclusion.

As a weatherman I get it everyday. Tomorrow’s forecast will manifest itself tomorrow. What a wonderful world if you did not bust it wide open for the entire world to see. When this Earth hands it to you, God help you.

Just a couple of weeks ago I was about half way between Phily and Baltimore. What a great place to be for a once in fifty year storm. I nailed it. I called for 2 ft of snow 36 hours in advance. I whipped the local meteorologist a**. Hort, I guess an image man can never feel that. I will not mention all the times this planet handed me my lunch.

Your images are legionary. Your passion drives you onward. At least we have a passion.

It is about time I post a forecast on this Forum. This is prime-time for Meteorologist to shine. I will dispense with the formalities.

Moisture will return in advance of the next Arctic surge on Tuesday. Snow will develop in Kansas with 3-6 inches of snow. The system will move East with Snow Potential over Oklahoma, Arkansas. Northern Louisiana, North Mississippi, North Alabama, North Georgia, North and South Carolina.

Do I love this time of year? You bet ya.

Fred

sol 2111 ( Jan 1, 2010 ) L234567 saturated false color:

with links to a 3D infrared / visible and a more "realistic" panorama.

The false color images of the tracks are one of my favorites. There is literally colorful mineralogy going on here.

Er, Ben I finally figured out what your comment in reply 51 means. I didn't point ouf that the image in reply 45 was 3D infrared / visible saturated false color image and that the soil comparison was between the white/orange ( infrared/visible ) soil on the gnomon and the undisturbed ground soil and the white/red ( infrared/visible ) soil in the rover track.

Is there anyplace on the Earth where the soil tracks of vehicles are so diffrent than the undisturbed soil?

Fred, every new picture is a rush for me. I am surprised the resident weather guy hasn't commented on any of the recent Meridiani clouds. In particular, can you determine if these clouds are water - or dust?

Here are my Meridiani cloud images.

Bill Harris, thanks for posting that "Lost City" serpentinization link in reply 42. I learned that the serpentinization process that is heating and circulating the water under this particular area of mid-ocean ridge is kept active by the ongoing tectonic fracturing of bedrock. Without the opening of new fractures to expose dry unaltered rock to seawater the whole process would stop. Mars doesn't appear to be tectonically active in the present day, so is it likely that serpentinization could be proceeding rapidly enough to generate large methane plumes? Is this type of abiotic serpentinization process the hypothetical alternative to a biotic process? How on Mars and at present can large volumes of igneous rock be being brought into contact with water for the first time?

Bill, Reply 49. There is nothing wrong with the RAT. See the Opportunity section of this Planetary Society report.

[link]

Bill, Reply 49. There is nothing wrong with the RAT. See the Opportunity section of this Planetary Society report.

[link]

Quote from the aforementioned Planetary Society report:

“We've completed 1.5 millimeters of grinding on Peck Bay,” Squyres announced earlier this week. On its Sol 2109 (December 29, 2009), Opportunity was slated to take the RAT away and take pictures of the grind spot with the MI, “to see how well we did,” he added. “Then we're also going to image the RAT bits to see if we can get a sense of how much RAT bit capability we lost in doing the grind.”

There is no way for the rover to tell exactly how old the rock is, Squyres said, but the compositional analysis completed this month seems to support the leading hypothesis that Marquette Island came from deep down under, expelled from beneath the surface during an ancient impact.

So I've read-- the RAT is OK. This grind had me a little worried-- it was unusual in that the cuttings were not brushed away afterwards and Oppy was looking at the RAT. I worry about the old girl...

Kye, I'm sure that this rock is significant but I'm not certain what it can tell up with the resources we have to study it. It's like a big Jigsaw puzzle on the table-- the pieces of the puzzle fit and that may lead us to answers. But if the chicken ends up with duck feet, it may not be a good answer and we need to look at other puzzle-pieces.

But seeing that we have a (supposed) gabbro and know the presence of water and methane we can keep an eye out for thay smoking gun of serpentine. Same thing as with phyllosilicates-- feldspars weather to a clay in the presence of water so we've been pon the lookout for that.

--Bill

Bill or CW2, I am still at a bit of a loss as to how they can differentiate between ejecta (Martian)or meteoric (astroidal) origin for MI with the tools they have. Ni content alone would seem inufficient. Can you provide any insights?

The other key question would be, if there has been aqueous alteration, whether this occurred prior to impact ejection or was due to ground water after deposition at Meridiani. I guess MI of the Ratted area after brushing could perhaps answer that question as post impact alteration would probably only be skin deep (see the link on investigation of Martian Meteorite MIL0334).

http://www.lpi.usra.edu/meetings/hydrous2009/pdf/4036.pdf