On the Road Again - volume 5 - Page 11

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Barsoomer


Posts: 344

Reply: 201



PostPosted: February 18, 2010 11:05 PM 

In the images of reply 192, at the bottom right, 3 hornlike protuberances. Still there when the R and L eye images are placed side-by-side to be viewed in stereo.

LWS


Posts: 3062

Reply: 202



PostPosted: February 18, 2010 11:12 PM 

Serpens, Barsoomer, Hort;

These berries at the edge of the rock are the kind of berry stems / stalks to which I am usually referring. They have eroded down to a diaameter and length that has no appearance of wind tails although there may be wind tails associated with the berries that are essentiaally flat on the rock surface. The Pancam image is a RAD image and the berries and stalks can be clearly seen. I have not been able to find a similar image showing stalks from the MI.



Original Size here

Winston

LWS


Posts: 3062

Reply: 203



PostPosted: February 18, 2010 11:18 PM 

Testing

LWS


Posts: 3062

Reply: 204



PostPosted: February 18, 2010 11:41 PM 

Hi Barsoomer;

Here's an anaglyph of your #192 rocks.

Original Size here

It looks like an interesting area.

Winston

Barsoomer


Posts: 344

Reply: 205



PostPosted: February 19, 2010 12:53 AM 

Re: the "hornlike protuberances." After staring at them for some time, I think they are an illusion caused when a ridge catches the light on a rock that is otherwise in shadow.

Ben


Posts: 2270

Reply: 206



PostPosted: February 19, 2010 1:15 AM 

Great image in #200.
It looks like you can see at least three layers of the fracture fill which IMO confirms ccyclic,lamilar, deposition.

Impact melt would have been almost instantaneous and formed a single layer .

Plus the often repeated fact; how could a tiny impact have generated that kind of heat? And if it did ;wouldn't the contacts with the host rock show some effect.?

And as John has repeated,where is the breccia?

I have not seen a single thing that supports melt and as far as I am concerned the case is closed.

marco


Posts: xxx

Reply: 207



PostPosted: February 19, 2010 5:42 AM 

we share the same interest

hortonheardawho


Posts: 3465

Reply: 208



PostPosted: February 19, 2010 10:56 AM 

The sol 2159 APXS target is a cluster of fused berries.

Barsoomer, I had a look at the same area of reply 192 in different lighting and the "horns" are strictly shadow differences on the rocks. If you like I can post a comparison animation.

Barsoomer


Posts: 344

Reply: 209



PostPosted: February 19, 2010 11:44 AM 

> It looks like you can see at least three layers of the fracture fill which IMO confirms ccyclic,lamilar, deposition.

> Impact melt would have been almost instantaneous and formed a single layer .

> Plus the often repeated fact; how could a tiny impact have generated that kind of heat? And if it did ;wouldn't the contacts with the host rock show some effect.?

Some component of the rock with a low melting point might be melting, but not the rock as a whole. Thus, the melt might retain some aspects of the pre-existing layering. I would think in repeated episodes of fracture fill, the cementation would tend to merge. In any event, any layering should follow the gravity gradient of the cavity. It would be a coincidence if this matched the layering of the rock.


> And as John has repeated,where is the breccia?

I don't have an answer to this, just that maybe this is not your classical impact melt.

> I have not seen a single thing that supports melt and as far as I am concerned the case is closed.

There must be some reason why the professionals on the MER science team are still entertaining the idea of impact melt. Presumably they have access to additional data from the other instruments that are giving them pause.

Barsoomer


Posts: 344

Reply: 210



PostPosted: February 19, 2010 12:28 PM 

Sideways view of the crust from these hazcams. Lots of bumps that seem large compared to the berries on stems.

Bill Harris


Posts: 72

Reply: 211



PostPosted: February 19, 2010 3:31 PM 

>Some component of the rock with a low melting point might be melting, but not the rock as a whole. Thus, the melt might retain some aspects of the pre-existing layering.

The mineralogy of the rock here is well understood. What low-melting point constituent would cause this?

>I would think in repeated episodes of fracture fill, the cementation would tend to merge. In any event, any layering should follow the gravity gradient of the cavity. It would be a coincidence if this matched the layering of the rock.

Give examples of this, either at this site or elsewhere. I don't see what you're saying.

>I don't have an answer to this, just that maybe this is not your classical impact melt.

So what other types of impact melt would it be? Baroque? Art Deco? Or my favorite, Patty?


>There must be some reason why the professionals on the MER science team are still entertaining the idea of impact melt. Presumably they have access to additional data from the other instruments that are giving them pause.

It is the concensus of the geological professionals on this board that an impact melt is unlikely, AFAIK. JOOC, what is your educational/professioanl background in geoscience?

--Bill


Kye Goodwin


Posts: 1166

Reply: 212



PostPosted: February 19, 2010 3:41 PM 

I see about 10 flake-like protrusions on this rock which I take to be fill remnants on stems:

I was initially enthused, thinking that fill-remnants-on-stems might be a source of information about berries-on-stems through comparison and contrast. Trouble is that we can't know what this looked like right after the impact. Were the remnants in contact with the rock over their whole lower surface initially and the rock has eroded away except for the stems? Maybe fill material has eroded away leaving stems of fill. Maybe this was a complicated fill that included coarser material which has fallen out leaving stems only where there was good attachment to start with.

But, OK, I think it is reasonable, as a thought experiment, to assume that the fill stems are remnants of the erosion of either fill material or rock material that once filled the space under the remnant flakes. The attachment between fill and rock could not have been too fragile as it had to survive the impact. Then it is hard to square the fill-stems and berry-stems as products of the same erosive process. The berries on stems apparently can't be "undercut" very much at all or the stems would be cut through but the fill remnants on stems have been deeply "undercut". Hmm?

Barsoomer


Posts: 344

Reply: 213



PostPosted: February 19, 2010 4:20 PM 

>>Some component of the rock with a low melting point might be melting, but not the rock as a whole. Thus, the melt might retain some aspects of the pre-existing layering.

>The mineralogy of the rock here is well understood. What low-melting point constituent would cause this?

Possibly the berries. The fused berries would certainly suggest melting. I know this seems inconsistent with the berry bowl measurements of hematite, but those may be more indicative of the surfaces of loose berries rather than the interior composition of berries in place.

> JOOC, what is your educational/professioanl background in geoscience?

The point I made was about the content of the status report of the MER science team and their access to additional information currently unavailable to the public. How is my background relevant to that?

LWS


Posts: 3062

Reply: 214



PostPosted: February 19, 2010 7:39 PM 

Hi Barsoomer; Just a little support for your #213.

You are not alone in your suggestion that the berry bowl measurements of haematite in berries might not indicate that the berries are completely or even mainly composed of haematite. The paper below suggests not only that haematite might be a relatively small constituent of the berry bowl berries but that the whole surface of meridiani is covered with a thin layer of haematite and there is no significant difference between the content of Haematite in the berries and that of the soil surface on which they sat.

">here

But I really must make a few more points about this whole question of impact melt vs. fracture fill.

Speaking purely as a layman re. space science, geology, etc. but as someone with a Masters degree and a Ph.D. who used to be a scientist but has not been on a laboratory bench for about 2 decades, I wonder if the geologists who totally discount the possibility of impact melt being involved in the new phenomenon we are seeing and also consider that the concepcion crater is much older than the NASA people are estimating, have considered the following;

As far as I know, Oppy has not imaged meridiani rocks partially covered with a relatively thick dark crust at any of the craters it has visited over its 6-year trek in Meridiani.

Shouldn't this suggest that we are looking at a new phenomenon and not one we can go to the textbooks and say; yes, it is such and such a thing, described by an eminent geologist in some paper or book? Yet the geologists are saying it is not (classical) impact melt it must be (classical) fracture fill.

We have seen many instances of fracture fill at every crater Oppy has visited but none of them are as ubiquitous on rocks around the craters as this peculiar dark covering. This "skin" covers all orientation of surfaces on individual rocks and so is distinct from the typical fracture fill. In several cases there are no nearby or contiguous rocks that can be identified as ones that fitted together before the impact and so would have been subject to fracture fill in their earlier pre-impact environment. There are several isolated rocks with this "strange" covering that cannot be correlated with typical fracture fill.

Why don't we see evidence of similar "fracture fill" on other rocks on other craters in Meridiani? Could it be that the concepcion crater is indeed very young. Perhaps the significant degredation of the covering with so many flakes sitting on the ground near the rocks or hanging precariously on the sides of rocks, suggests that in a relatively short time all the flakes will have vanished leaving no trace. But, strangely enough, the true fracture fill sitting between rocks will probably remain for eons.

Cant we see that it is most likely that the material covering the rocks is definitely NOT fracture fill just as it is also NOT classical nor baroque impact melt.

Could one of the geologists tell us how many instances of Breccias Oppy has found at the large craters that it visited where presumably the temperatures generated by the impacts were most likely much higher? I think none.

If they are indeed none, could it be that the conditions on Meridiani militate against typical garden impact melt or formation of breccias?

Could it also be that the relatively low heat of the impact might cause surficial melting of blueberries (if they are indeed not fully made up of Haematite) and the formation of a "skin" covering the rocks as they are ejected and that this skin erodes relatively rapidly thereafter and leaves no trace after several millenia?

Could the fact that we are seeing several instances of "rotten rocks" around concepcion be indicative also of the young age of the crater? None of these have been found near any other crater.

I ask again, why would NASA before it got close enough to discern the details of the coverings suggest that it was impact meld and still seem to be sticking to their guns despite having access to the evidence the geology community in this blog is using to claim that there is no impact melt and that the crater is very old.

Just a few points to ponder.

Winston

LWS


Posts: 3062

Reply: 215



PostPosted: February 19, 2010 7:44 PM 

Oops! Reference to Brueckner et al's paper on Haematite in Berries below;

here

Winston

LWS


Posts: 3062

Reply: 216



PostPosted: February 19, 2010 8:31 PM 

Testing

Burt's anti-concretion paper

here


http://www.lpi.usra.edu/meetings/lpsc2007/pdf/1922.pdf

Here's an image with rotten rocks at extreme lower right corner.

Barsoomer


Posts: 344

Reply: 217



PostPosted: February 19, 2010 9:23 PM 

Very nice paper, Winston.

The mention of Mn as a component in the measurements caught my eye. It is curious that Manganese forms both dendritic concretions, which have been called pseudo-fossils because they have been mistaken for fossils, and also nodular concretions. If both could form in a single environment, then one might have something that looked like berries on a branching lattice purely through inorganic processes.

LWS


Posts: 3062

Reply: 218



PostPosted: February 19, 2010 11:04 PM 

Barsoomer;

Which paper?

The question of the identity of the berries is really vexing and contentious and will almost certainly not be totally explained until better equipped rovers sample them at Meridiani. The best answer for now is some sort of concretions but there are so many aspects to them that suggest that they are not typical concretions that the concretion hypothesis should really be viewed as just that.

E.g. Tonight I was looking at a composite I did of the newest image of Chocolate hills posted today on Exploratorium.

Original Size here

It is essentially an extreme PanCam closeup and one can see the berries quite clearly and the "wind tails" behind them. What was amazing to me is that the large majority of the berries appear to be positively geotropic and that the wind tails on the rock segment on the right closely resembled wefts of rhizoids. What geological reason is there for practically all the berries that are not sitting on the top of the rock to be oriented pointing down at the ground?

And why should those "wind tails" crisscross at such relatively large distances from the berry which created the conditions for the tail to form and why can one trace the wind tails across the criss cross pattern from, or to, their origin at a single berry?

There are a lot of questions out there that are difficult to answer from a geological standpoint only and I won't be surprised if Concepcion (perhaps being true to its name) throws up a few more before Oppy heads south.

Winston

LWS


Posts: 3062

Reply: 219



PostPosted: February 19, 2010 11:09 PM 

Oops;

I've again messed up the image above. Please bear with me

Original Size here

Serpens


Posts: 169

Reply: 220



PostPosted: February 20, 2010 12:02 AM 

Barsoomer and Winston, Impact melt is the result of an instantaneous pressure increase. For a small impact like this into poorly consolidated rock I think all you will end up with is fractured rock and dust. Some of these severelly impact fractured remnants would end up looking like Rotten Rocks!

Ben, any clue which way used to be up for Chocolate Hills? If it is in fact upside down in our field of view than your multiple layers, and Hortonheardawho's comment on the erosional differences above and below the horizontal crack would seem to have a simple explanation: We are fortunate enough to have access to a rock that represents the upper boundary of repeated recharge events, (or the upper wicking limit of such).

I think everyone is entitled to an opinion or hypothesis on what we see. But from everything I have been able to research some facts on the berries seem pretty clear.
1. They are a hematite and rock fragment mix.
2. The berry bowl measurement was clever and scientifically robust. From this and pancam false colour the berries have a high hematite content.
2. The hematite in the berries was a low temperature formation.
3. From Bell's pancam analysis the mix is consistent across the berry interior - not just a hematite outer layer (sorry Ben I have to disagree with you on that one).


Sad

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