On the Road Again - volume 5 - Page 5

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Barsoomer


Posts: 344

Reply: 81



PostPosted: February 11, 2010 11:40 AM 

When mathematicians can neither prove nor disprove some statement, they often can make progress by assuming it is true, and seeing what the consequences are.

I think it is an interesting exercise to assume as a working hypothesis that the berries are some kind of growth (whether biological or inorganic) with the stems as feeder tubes, and then examine what the observations might imply about their "life cycle." For example, the berries on top of Chocolate Hills do not have prominent stems.

One scenario that might fit the observations is as follows. The berries on stems grow underground in some muddy soil environment. Porcupine Rock may be an example of a lump of muddy soil with berries that has been ejected in a relatively pristine state. (Moisture on the surface may be questionable, but moisture underground seems quite possible.)

(Concepcion is undoubtedly young; whether 1000 or 100,000 years does not really matter. Any post-impact erosion we see there is not the billion-year erosion that could carve structures unique to Mars---we should see Earthly analogues of the erosion. AFAIK, we do not see delicately carved berries on stems resulting from differential erosion on Earth.
So the berries on stems are more likely pristine rather than highly eroded.)

We do not see berries on stems at older craters because the constant dust storms have filled them. That is, the berry lattice becomes the skeleton for a rock formed by dust deposition. Think of an air filter becoming filled with dust and other debris. Thus, the visible parts of the lattice superficially resemble bedding planes for the rock.

Many eons later, the rock in turn may erode away and leave the berries, sans stems, lying on the surface as a lag deposit. New rocks may later form that incorporate the stemless berries.

There may be other ways of removing the stems. For example the impact of an ejected lump of mud on a hard rock Chocolate Hills might break off the delicate stems.

I realize this may sound incredibly naive to the geologists on this forum, and I ask their indulgence for my speculations. I would be happy to be educated as to why this can't possibly be true.

Ben


Posts: 2270

Reply: 82



PostPosted: February 11, 2010 11:41 AM 

Serpens; Your reply #76 I always have to consider the dessication cracks so drag in the playa idea.
Lets compromise and say it was a "coastal playa" Very Happy

hortonheardawho


Posts: 3465

Reply: 83



PostPosted: February 11, 2010 11:57 AM 

sol 2151 ( Feb 11, 2010 ) colorized MI pan of the MI redo:

the MI sequence was redone 2 hours 15 minutes later than the 2150 sequence.

Unfortunately, the later time makes the shadows different than the pancam image takem an hour earlier that was used to colorize the image.

This means that the color near shadows may be wrong.

Also the image area is not flat so the bilinear registration used introduces some color misalignment near the higher areas near the top of the image.

I will work on colorized 3D pairs this afternoon.

Kevin Author Profile Page



Posts: no

Reply: 84



PostPosted: February 11, 2010 1:25 PM 

Is it me or does there seem to be a greater concentration of Berries around the craters visited then elsewhere on our travels?

There is certainly a lot here and Victoria was smothered in them.

Like Baroomer forgive a little indulgance from a geology novice.

LWS


Posts: 3062

Reply: 85



PostPosted: February 11, 2010 1:31 PM 

Hi Hort;

Much better image (reply #83) even though colour is not optimized. Berries appear to have more reflective surfaces than is generally seen on berries from the surface rock or soil. They have the general look of earth concretions. Also, there seems to be a fair amount of damage to the berries in one area of the MI pano. Broken berries, split ones and hollowed out ones. The berries are also similar in size range and appearance to the Erebus berries.

Will await your 3D's for further study.

Winston

Bill Harris


Posts: 72

Reply: 86



PostPosted: February 11, 2010 4:09 PM 

Nice MI's, indeed. If the color is bothersome, hit the "grayscale" button or take the color with a smidgen of NaCl. I don't recall seeing Berries in a "fracture fill" matrix. This is turning into a nice, new, and oddly-shaped, puzzle piece.

And we've got more Pancams of the Sundial. I was wondering how it was... Wink

I'm still befuddled by "Jagna". I'd like to see views of the lefthand face, the low angle here foreshortens things. My first impression of that lefthand face is that it is weathered since it has a bit of a tan color, compared to the righthand face. I was thinking at first that this rock was just a part of the "Chocolate Hills" rock that had broken off and settled after they landed, but the more i lok, the more different (albeit similar) the two rocks look.

The "rotten rock" mentioned by Winston and Ben look jst that. My forst impression was they appear like a deeply weathered gneiss or granite with respect to color and texture. Of course, they're not. The "AhHa" is that I don't recall seeing a rock like this in any of the exposures we've looked at in this traverse. It may be a new unit, it may be a piece "shocked evaporite", it may be an intermediate weathering form. I'd like to see some MI's, and a brushed surface.

I'm sure that any Geologist would welcome seeing evidence of biological manifestations. But within our experience, all we can safely say that we see is rocks, dust and more rocks.

But hope springs eternal...

--Bill

Ben


Posts: 2270

Reply: 87



PostPosted: February 11, 2010 4:47 PM 

Here is the chronology illustrated in Hort's fine #86 image.

Alternating beds of Meridiani sulphates?
were deposited in conditions that ranged from a wet surface to shallow water.

Spherules formed in these beds below the water table by concentric mineral growth of a hard layer around (dust-ball)?nuclei.

Drying conditions ensued during which the water table dropped and dessication cracks formed.

Soon after or congruently, the resistant spherules were released from the exposed,dry, surface by erosion and some as Serpen's pointed out
, rolled into the open cracks

The water table again rose( but not to the surface) and began filling the cracks, from the outer walls inward ,by the depositon of laminar,relatively hard fill material. As it was deposited,his material engulfed some of the loose spherules that had collected in the cracks.

A later impact ejected some of these shallow rocks and has now provided a picture of what happened.
One persons opinion anyway.

Kye Goodwin


Posts: 1166

Reply: 88



PostPosted: February 11, 2010 4:53 PM 

Thanks Horton for all your work on these difficult MIs.

I don't see so much "aha" as "oh yah this again". The mainstream interpretation includes the suggestion that solid fines - dust, soil or rock debris has fallen into the bedrock fractures and somehow become cemented together into a fill. The spherules sin these MIs seem to be slightly cemented together in places and some are closely enveloped in the fine fill material. We could say that this is the very first occurrence we have seen at Meridiani of spherules that are both attached to rock and messily packed together. I'm pretty sure that they have much more in common with loose spherules than the spaced-apart spherules directly attached to the bright rock. There appear to be fragments and non-spherule debris packed in with the spherules, another indication that these berries did not form in the fracture but were more likely introduced to it mechanically along with the other closely-packed coarse-grained miscellany.

The outstanding mystery to my eye is how the coarse material - mostly spherules - and the fine material that makes up most of the fill have been deposited in segregated sheets. Here is a better example of the discrete thin sheets (layers ?) of coarse and fine grained material in a fill on this other nearby rock - center left:

Again, you want to see Horton's binocular version (uploaded Feb 5). The coarse stuff in the pancam looks enough like the coarse material in the MIs that it is reasonable now to expect that it too is somewhat size-sorted spherules and other odds and ends. The coarse material appears to form a uniform thin layer over the finer -textured fill material, as if it too were "cast" in the fracture. Strange.

hortonheardawho


Posts: 3465

Reply: 89



PostPosted: February 11, 2010 5:20 PM 

Here are the sol 2151 3D pairs.

One of the puzzles to me in these MIs is the small dark grains lightly peppered ( salted?) throughout the images.

Perhaps pulverized dark rock that was thrown in the air by the crater formation and gently rained down afterwards? They seem to be concentrated in the rough areas that could more easily trap the grains.

I did a few colorized 3D MIs but decided there wasn't enough color differentation to warrent the color. Just think gray.

Sorry ot took me a while to post the links. I had a nap this afternoon after working on the MI 3D and just awoke a few minutes ago. I'm off to photograph a sunset now.

Bill Harris


Posts: 72

Reply: 90



PostPosted: February 11, 2010 8:35 PM 

Nice stereo pairs!

I noticed the small dark grains and suppose that they are basalt sand and/or hematite sand. Remember, this is the freshest, least-weathered material we've seen in our 6 years.

--Bill

serpens


Posts: 169

Reply: 91



PostPosted: February 11, 2010 10:06 PM 

Ben, while there was a bit of 'contamination' in other fracture fills, as Bill says this level of berry infill is unique. The other fracture fills were more 'pure' which seems to imply that either the fractures did not extend to the surface, the surface was clean and not eroded or the fracture fill formed concurrent with berry development.

I think this find is important because it means that for this area the fracture fill occurred not only after berry formation, but after the berries had been eroded from upper layers of rock. So what we seem to have here is further confirmation of cycles of inundation, desiccation, deflation and recharge.

And Winston, geology and biology are not so far apart - hence geobiology. If the berries are concretions as they seem to be then bacterial mediation in their formation cannot be dismissed. But there are other non biological mechanisms too. Unfortunately the MER are mobile geologists, not biologists.

Kye Goodwin


Posts: 1166

Reply: 92



PostPosted: February 11, 2010 10:34 PM 

It seems pretty clear that there are places in the micro-images where the fine-grained fill material cements the coarse fill particles together. Also, there are several examples of spherules embedded in the fine fill material. This means that an interesting transformation must have taken place. Either the fine-textured material was once a loose powder and has become a cemented solid, or the fine-textured material was once a liquid and has become a solid. Have I missed any possibilities? Is there any evidence to favour one theory over the other? Is there any way of knowing whether the fine material or the coarse material entered the fracture first? Can we tell if they were moved into the fracture together or separately?

Kye Goodwin


Posts: 1166

Reply: 93



PostPosted: February 11, 2010 10:54 PM 

It seems pretty clear that there are places in these micro-images where the fine-grained fill material cements the coarse fill particles together. Also, there are several examples of spherules embedded in the fine fill material. This means that an interesting transformation must have taken place. Either the fine-textured material was once a loose powder and has become a cemented solid, or the fine-textured material was once a liquid and has become a solid. Have I missed any possibilities? Is there any evidence to favour one theory over the other? Is there any way of knowing whether the fine material or the coarse material entered the fracture first? Can we tell if they were moved into the fracture together or separately?

Bill Harris


Posts: 72

Reply: 94



PostPosted: February 11, 2010 11:08 PM 

Serpens--

Yes, the biosphere and geosphere are inextricably linked, on Earth and presumably elsewhere.

One of the serious environmental problems here with mineral extraction is the oxidation of iron sulfides twhich result in free iron, sulfates and acids. This is the cause of "acid mine drainage". Although it is a chemical reaction involving O2, H2O and FeS, it is also greatly mediated by an iron bacteria. Life is everwhere, and persistent.

This is indeed a wondrous site.

--Bill

Bill Harris


Posts: 72

Reply: 95



PostPosted: February 11, 2010 11:19 PM 

Rover update from NANA/JPL
They still suggest that the "fracture fill" is impact melt. I'mnot convinced, but it is something to consider til disproven.

[link] #sol2145


sols 2145-2151, February 4-10, 2010: Opportunity Studies 'Chocolate Hills' Rock

Opportunity is exploring around the rim of the very young crater "Concepcion."

On Sol 2145 (Feb. 4, 2010), the rover made a 10-meter (33-foot) approach to a rock target called "Chocolate Hills." This rock target is of interest because it exhibits a dark rind or crust that may be impact melt. On Sol 2147 (Feb. 6, 2010), Opportunity completed a 2-meter (7-foot) short approach to bring the target within the work volume of the robotic arm (IDD). On Sol 2149 (Feb. 8, 2010), the rover performed a small turn-in-place to position the target within reach of the IDD with its 4-degree-of-freedom azimuth limitations. On the next sol, the IDD collected a Microscopic Imager (MI) mosaic of the dark rind and then placed the Alpha Particle X-ray Spectrometer (APXS) for an integration. On the following sol, another set of Microscopic Imager mosaics were collected and then the Mössbauer (MB) spectrometer focused on the target called "Aloya."

Serpens


Posts: 169

Reply: 96



PostPosted: February 12, 2010 12:18 AM 

Bill, I suspect the 'impact melt' comment was made when what in MI looks like fracture fill, was a smudge on a distant rock and they had spent too much time studying meteorites.. Time will tell, but I really cannot see what they base that assessment on.

Barsoomer


Posts: 344

Reply: 97



PostPosted: February 12, 2010 1:29 AM 

By "impact melt" do they possibly mean melted permafrost, i.e. mud, or does the term refer only to molten rock?

Bill Harris


Posts: 72

Reply: 98



PostPosted: February 12, 2010 4:21 AM 

This is the second weekly update that they've mentioned "impact melt", so either they've found out something new or an intern has found a new buzz-word. Rolling Eyes

The melting point of MgSO4 is 1124C (2055F), Decomposes. Silica is a bit higher.

--Bill

LWS


Posts: 3062

Reply: 99



PostPosted: February 12, 2010 11:14 AM 

Bill; As a layman, I wonder if the Official promotion of Impact melt is not very near the truth. If it was a relatively recent impact then the "rotten rocks" we see around the crater rim might be a resultant of the same impact melt and the area which shows a gouge in the soil near chocolate hills and rotten rocks might also be impact melt. If so, we are looking at a really young crater as NASA/ASU hypothesized from the start. the laminae being shed on chocolate hills and other nearby rocks could be signs also that show how berries could have fallen in a chaotic pattern unlike how we've seen them before onto lower less affected sides of the rock.

This area then becomes a very important laboratory as the whole annulus should then be examined thoroughly as far as possible to see the range of effects on and of the impacting ejecta around the crater.

There should be some way of gauging how deep the ejecta rocks came from underground and a thorough examination of rocks from different imputed depths could give a picture of berry incidence at depth.

I am almost certain that the initial picture of a unilayer of berries at the surface is totally incorrect from the purgatory studies and other observations.

After a few months of investigations here the Endeavour trip should be very interesting as deeper depths could be studied.

I am also wondering now if those piles of dark stones that Oppy passed by with nary a look might have also been rotten rocks affected by impact melt.

Serpens; I'm a biology dinosaur and I was totally unaware that people are now seeing the connection between Geology and Biology. It's something that became clear to me from first seeing the Oppy and to a lesser extent the Spirit MI's. Some of those structures which geologists accepted as typical Geology seemed to me to be typically biological. I suspect someday we will see a merging of the two fields.

RE. water on Meridiani, I suspect the fat lady has not yet sung her last note.

Winston

Barsoomer


Posts: 344

Reply: 100



PostPosted: February 12, 2010 12:19 PM 

Hematite has a high melting point of 1500 Celsius. If Chocolate Hills itself partly melted in the impact, it might have concentrated the berries in a chaotic pile.

Some new pancams.

In the large rock at bottom right in the above image, the berries appear to be concentrated in layers that are interspersed between the other bedding planes.

Does the rock in the above image contain dendrites? (A branching type of concretion.)

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