On the Road Again - volume 5 - Page 12

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Barsoomer


Posts: 344

Reply: 221



PostPosted: February 20, 2010 1:09 AM 

Thanks, Serpens for those points. One question: in your opinion, could fracture fill have melted in the impact? That would be better consolidated and might (since we don't know the exact composition) have a lower melting point.

Serpens


Posts: 169

Reply: 222



PostPosted: February 20, 2010 1:10 AM 

Winston. Looking as Hortonheardawho's x-eye at 179 I can now see the apparent stalk remnant on a berry at the edge of the fill. Your query and Hortonheardawho's comment on an ah ha moment are now clear. But I don't see this as significant. A berry erodes out of surface rock, a windtail forms and turns into a stalk, stalk breaks, berry falls down an ends up in a crack. Fracture fill forms and embeds this berry like the others.

Bill Harris


Posts: 72

Reply: 223



PostPosted: February 20, 2010 7:19 AM 

Serpens:

> any clue which way used to be up for Chocolate Hills?

Ah, the classic geological conundrum when encountering a piece of float. I've not seen any sedimentary features in the current working face that give a clue. Looking at the the lowermost face, the one facing the Rover, in the Forward Hazcams and enhancing shadow detail, I think I can make out polyagonal drying cracks. These cracks, at the cross-section of the working face, do seem to penetrate to the first prominent bedding plane. I conclude that this leftmost "Chocolate Hills" rock is oriented "upside down", the bedding plane nearest us is TOP and the one farthest us is "BOTTOM.


--Bill

James


Posts: 3

Reply: 224



PostPosted: February 20, 2010 10:38 AM 

Could the 'impact melt' (if such it is) have been created by some previous major impact, which the present small, young, low-energy event has merely revealed?
With respect to berry stalks... Perhaps the erosional effects of dust devils should be taken into account. Brief, repeated, rotational dust-blasting could produce strange results.

Ben


Posts: 2270

Reply: 225



PostPosted: February 20, 2010 11:41 AM 

Bill; Your #223 analysis is right on target .All good geologists would agree Wink

Barsoomer


Posts: 344

Reply: 226



PostPosted: February 20, 2010 2:37 PM 

If the coating is fracture fill, and if it shows layering indicative of repeated recharge episodes, then wouldn't the fill layering (i.e. the vector normal to the planes of the layering) point in a direction that was vertical when the filling took place (i.e. prior to the impact)?

With respect to dust devils, AFAIK the Opportunity rover has never observed dust devils at Meridiani (although Spirit at Gusev has observed many dust devils).

Bill Harris


Posts: 72

Reply: 227



PostPosted: February 20, 2010 3:38 PM 

John:

>Perhaps the erosional effects of dust devils should be taken into account.

Even though we've not seen dust devils here, you can't see what you can't see. The atmospheric dynamics are the same: cold ground, solar heating, thermals form. Dust devils are easily visible at Gusev because the ground is much dustier. Dust devils are much lews visible because the dust is armored with berry-lag and the wind stirs up no dust. Look at the number of cleaning events Opp has experienced.

Not so much dust devils, but when you get near the ground, and especially when the ground littered with boulders and wind obstructions, there will be turbulence.

Ben-- thanks, I still had doubts about UP-ness on that rock.

--Bill

Kye Goodwin


Posts: 1166

Reply: 228



PostPosted: February 20, 2010 4:01 PM 

LWS, I've been wondering for years now about that Brueckner paper that you linked in reply 215. Because of it, I haven't ever been sure whether the hematite is evenly distributed through the berries or is only a coating.

Serpens , re your 220:

1. If there are rock fragments in the berries they must be smaller than the MI can resolve. Let's say there is likely material other than hematite in the berries, but none has ever shown up as a visible fragment, to my memory.
2. The Brueckner paper (reply 215) discusses the berry-bowl experiment at length but does not conclude that the hematite is distributed through the spherules.
3. How about posting something with that Bell pancam argument. Isn't the problem with the pancam or even the MI that a coating too thin to be imaged in section on a ratted berry would still be thick enough to produce a Mossbauer signal? I'm not pre-judging though. I've not dug into this yet. If the berry exteriors and freshly exposed interiors look identical to the pancam then that's a strong argument against the coating theory.

Barsoomer


Posts: 344

Reply: 229



PostPosted: February 20, 2010 4:19 PM 

There is also no indication of dust devil trails at Meridiani in orbital images taken by MRO or MGS. Such trails at Gusev are very apparent from orbital observation.

Bill Harris


Posts: 72

Reply: 230



PostPosted: February 20, 2010 5:54 PM 

This is a contrast-enhanced copy of an MOC image of the Endurance-Erebus area of Meridiani. I may have this misinterpreted, but I suspect that the dark traces were left by unusually strong dust devils. As far as I can see they don't match topo features (other than albedo). I've not done this yet, but I may try to see if I can see anything on later MRO imagery.

Mars, always a surprise.

--Bill


LWS


Posts: 3062

Reply: 231



PostPosted: February 20, 2010 8:29 PM 

Hi Bill, Serpens, Ben, Kye ;

Re. Bill's 230. I would like to suggest that the dynamics of wind flows at Meridiani planum, and even Gusev, are still not well understood. Wind obviously moves fine dust at meridiani as borne out by the actual short studies in the dark streak area at Victoria and by the numerous Oppy cleaning events. However, whether or not the wind movements of themselves are capable of creating the intricate wind tails seen on some rocks at Concepcion is just speculation at this point.

Serpens; Re. the solid hematite hypothesis, I think it is not yet proven beyond a shadow of a doubt.

(Putting on my Conspiracy Theory Hat) Just consider that one of the main rationales for the choice of Meridiani planum as a landing site for Oppy was the supposed existence there of gray hematite and even the meridiani berries was predicted before Oppy landed. The Oppy studies were predicated beforehand on finding gray hematite which was supposed to indicate that ancient water previously existed on the site.

Around 2003, 2004 and 2005 Laura Kirkland published some interesting papers suggesting categorically that the spectra of haematite at Meridiani from TES and Themis data suggested that it was Fine Hematite and not Gray Hematite. She also suggested that the mini-TES was perhaps incapable of telling the difference and that the fine Haematite was probably a surface layer covering all meridiani surfaces. Laura Kirkland was an establishment scientist working in Texas on Nasa projects. Her published conclusions flew directly in the face of NASA and if true would make a nonsense of the whole Opportunity landing project.

I have seen several papers by Glotch et. al and others on the Berries and Hematite that do not even refer to her studies or to the Bueckner study I referred to earlier. Why would they not mention prominently that a major challenge to the bona fides of their conclusions on hematite and the berries had been shown to be false based on new data on the ground?

Those studies have a direct bearing on the question of the content of Hematite in the berries

I can find nothing Kirkland has done in this area since 2005.

Has she stopped working in the area?
Is she still working with NASA?
Has her work been discredited with new information coming out on the berries and hematite?

One of ypu might know and can put the record straight.

I've been collecting several abstracts and papers in this area but, in the case of the papers, they have been highly technical and I may not fully understand what they are saying. Googling KIrkland or Bueckner or fine hematite or gray hematite will bring up several papers or other documents that suggest that the Official story on hematite is not the only act in town.

Re. the Bery Bowl study, the paper by Bueckner et all, in my limited view does a good demolition job on the experimental design, etc. Where are the challenges to that study and its conclusions? How much reliance should we put on the models that are used in trying to understand the real Meridiani?

I'd be most grateful if one or some of the rock guys would look into this and tell us some more about what Kirkland is doing since 2005; What Bueckner himself is also doing etc. to clear up any hint of conspiracy re the hematite story.

Winston

Barsoomer


Posts: 344

Reply: 232



PostPosted: February 20, 2010 8:30 PM 

Conspicuous cone-shaped rock. Also an interesting rough-surfaced rock at the left near the bottom.

Bill Harris


Posts: 72

Reply: 233



PostPosted: February 20, 2010 8:49 PM 

Correction in Reply 230:

Erebus Crater is not visible in this image, it is below the lower right corner.

I looked at the MRO and other MOC images of this area and all are much lower contrast that this one. No backup documentation, so either we're on to something or we're nutso... Wink

--Bill

Serpens


Posts: 169

Reply: 234



PostPosted: February 20, 2010 9:01 PM 

Kye and Winston. I really think the need to analyse berries is past. Fresnel modeling has proved that they are not formed in surge clouds. I think your questions are answered in pages 108-109 of McLennans old paper 'Provenance and diagenesis of the evaporite-bearing Burns formation,Meridiani Planum, Mars'. Fortunately while most sites require membership or fees to view it is available for free with a bit of searching. http://epsc.wustl.edu/admin/people/publications/jolliff/mclennan_etal_2005_epsl.pdf

I have seen a couple of images of broken berries that seemed to have nucleation particles but you are right Kye that the terrigenous material is very fine. While the paper caveats that only the
outer 100 Am of the spherules can be analyzed visible through near infrared spectra of broken and abraded berries showed distinctive spectral responses for hematite. Multi-filter Pancam images of the interiors of abraded spherules indicate uniform compositions throughout. The hematite is not an outer skin.

Winston, thanks for the false color image at 202. This clearly shows that the berries have a hematite reponse, but the stalks are the same as the rock. Doesn't this Confirm that the stalks are host rock and that this is an erosional effect? I am with Bill. I think we should concentrate on the gifts of Concepcion, not revisit berries and stalks. Very Happy

Bill Harris


Posts: 72

Reply: 235



PostPosted: February 20, 2010 10:19 PM 

Well put, Serpens.

We are seeing interesting textures on nearby rocks and equally tantalizing glimpses at rocks further away. I may be getting over eager, but I wish we'd move faster...

--Bill

LWS


Posts: 3062

Reply: 236



PostPosted: February 20, 2010 10:41 PM 

Serpens; Re your reply #234.
Even though I admit that the consensus firmly considers that the berries are nothing more than concretions that are totally analagous to some of Earth's hematite concretions, I think that there are enough areas where unanswered questions still exist. As I indicated in an earlier post we look at one picture and you see wind tails while I see stalks AND wind tails. My #202 is a case in point where I think that visually the stalks at the top of the image are distinct from the wind tails that are clearly ramifying on the surface of the rock. I also think that the stalks emanating from the rock surface are also different from the wind tails from which they emerge. You, however, appear to be absolutely certain that the stalks and the wind tails are spectrally indistinguishable. Have you done a reliable spectral analysis that shows this beyond a shadow of a doubt? I agree that what we are seeing are erosional effects but only to the extent of wind or other agents removing the hardened dust that covers the berry stalk. I think that the picture shows real stalks and real wind tails and that the two are not the same.

As far as I recall, there was ONE MI which could be interpreted to have showed homogeneous contents of a fortuitously sectioned berry. Many Pancams showed broken and otherwise abraded berries. But these berries were on surfaces that have been found by Bruckner, Klinglehoffer and others to universally have a surface covering of hematite dust. Why couldn't it be that the pancam images were showing that dust on the broken as well as the intact berries? Also, how sure are we of the ability of spectral analysis of the pancam images of such small objects to resolve the signals from individual berries since these berries are not normally in contiguous piles.

Thanks for the McLennan paper. I already had it but it does not address all the concerns I have.

Anyhow. I am certainly enjoying the new images seen at Concepcion. I am looking for something new to emerge from the new situation with a young crater. Looks like geologists think that everthing has already been elucidated.

Let's agree to disagree.

Winston

Ben


Posts: 2270

Reply: 237



PostPosted: February 21, 2010 12:02 AM 

OK ; Now lets talk about all the dust piled around the ejecta in Barsoomer's 232.

Any thoughts on why ?

LWS


Posts: 3062

Reply: 238



PostPosted: February 21, 2010 12:11 AM 

Testing

LWS


Posts: 3062

Reply: 239



PostPosted: February 21, 2010 12:34 AM 

Ben

This very false colour image below shows the dust buildup well.

What's interesting about it?

Winston

Serpens


Posts: 169

Reply: 240



PostPosted: February 21, 2010 1:02 AM 

Winston. Reference Laura Kirkland, her home site is still up although not well maintained. But that would surely indicate that she is still there. [link]
Her email address is on the site if you want to follow up.

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