On the Road Again - volume 5 - Page 6

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Author Message
Ben


Posts: 2270

Reply: 101



PostPosted: February 12, 2010 3:06 PM 

Barsoomer; The berries seem to be concentrated along the more resistant of the alternating layers.
Maybe a function of the oscillating depositional environment that created the beds.
The rock surface you refer to appears to be covered w/fracture fill and the texture variations(ridges) are associated w/ its accretion in the void space of the crack.

hortonheardawho


Posts: 3465

Reply: 102



PostPosted: February 12, 2010 3:24 PM 

Here is the infrared / false color view of target "Aloya" - the stuff on top of Chocolate Hills. The area where the blueberries seem to be melted into the rock has a slight "green" tint in the infrared view. Perhaps a change in minerology here?

And here is a 3D closeup of "Canuba beach" rock - with an extremely long blueberry stem ( top rear ).

I asked a long time ago: how long does a blueberry stem have to be to "break" the wind tail hypothesis. Now add to that the question: how young does a blueberry tail have to be to "bury" the wind tail hypothesis?

And finally, what does a very long, very young stem associated with a very violent event do to the wind tail hypothesis?

It would be nice if all this could be formulated in a three parameter phase space to show that specific stems are well outside the parameter space.

I would guess that there are hundreds of stems around Concepcion crater that fall outside any "reasonable" volume in the parameter space.

If anyone is interested in the sunset I photographed last evening, look here.

Winston, I have regarded biology as a subset of geology for some time.

Whether there are "other" ways of making a living in the physical universe is a very interesting question.

One of my all time favorite novels that explores "life as we don't know it" is Robert Forward's Dragons Egg.

Barsoomer


Posts: 344

Reply: 103



PostPosted: February 12, 2010 3:52 PM 

Looking at Horton's wonderful 3D image of the rock on the rim of "Canuba Beach," I don't see how there can be much doubt that the rock is in a relatively pristine post-impact condition as a fragment of a larger rock that has been torn apart.

It would take eons of erosion or weathering to produce such intricately carved shapes, and it would be very odd if the youngest crater that Oppy has encountered is host to the greatest amount of erosive sculture of the outcrop rocks.

If indeed the rock surface is in an almost pristine condition after being ripped away from a larger rock, it follows that the stems are an integral part of berry formation and are not "wind tails" or other weathering artifacts.

Kye Goodwin


Posts: 1166

Reply: 104



PostPosted: February 12, 2010 4:17 PM 

IMPACT MELT? That is so Mickey-Mouse I almost can't believe it, but I don't think they necessarily have scientists writing these press releases. Why would they have to introduce impact melt when we've seen dozens of fracture-fills at widespread locations and there is no reason as yet to think that this is anything but the same phenomenon. Roosevelt shows similar crude laminations and some strong hints of embedded spherules as well:

Ben


Posts: 2270

Reply: 105



PostPosted: February 12, 2010 8:49 PM 

The presence of cyclic bedding is abundant on Mars and Caltech people attributed it to climate changes. You might find this interesting.
http://media.caltech.edu/press_releases/13214

Kye Goodwin


Posts: 1166

Reply: 106



PostPosted: February 12, 2010 10:53 PM 

Ben, Thanks for the link, Yes I've seen items on cyclic bedding before and it has helped me to understand how a single impact surge event can sometimes produces deep sedimentary deposits, even though the continuous ejecta blanket of a big one may be on average only a few meters thick. The elegant mega-layer deposits on Mars are places where a moving impact surge sheet has repeatedly overridden itself as it comes to rest. This clearly happens in rampart crater events at the distal extreme of the ejecta blanket producing a much thickened "rampart" around the crater. I have had other ideas, but seeing layering that repeats at intervals pretty strongly indicates to me that what we are seeing is stacked copies of a single surge. The repetition interval corresponds to one entire thickness of the surge.


Ben


Posts: 2270

Reply: 107



PostPosted: February 12, 2010 11:49 PM 

Kye; These layers appear to be very similar.
I don't see how a single surge event could create such conditions.
i.e. the ripples created by a stone thrown in the water are not identical.

John


Posts: xxx

Reply: 108



PostPosted: February 13, 2010 1:09 AM 

Ben, I posed a question about the layers at Becquerel crater some time ago. "Kye; These layers appear to be very similar." I'd thought the layering was from a different process than described in the report, tho cyclical. I can envision the explanation of the report. The layering is SO regular. I stated that the math was perfect. Reminded me of USGS elevation maps, the layering was so regular. I was somewhat chastised, and informed here that the layering was due to impact surge and the math was not perfect. I must agree with the Caltech report that the layering is due cyclical occurances.

hortonheardawho


Posts: 3465

Reply: 109



PostPosted: February 13, 2010 11:26 AM 

I have added the sol 2151 colorized MI 3D, including this peculiar detail:

I call the link between the main body of "whatever-this-stuff-is" and the blueberry a "blueberry bridge".

Ideas?

Barsoomer


Posts: 344

Reply: 110



PostPosted: February 13, 2010 2:13 PM 

> Ideas?

Blueberry melt? A few adjacent blueberries melted into each other as a result of the heat of the impact?

Some delicious treats at this site? Razz

Kye Goodwin


Posts: 1166

Reply: 111



PostPosted: February 13, 2010 3:00 PM 

Ben, John, Yes, almost everyone assumes that some sort of cyclic depositional process created the uniform layering. With this fundamental error going in there will never be any progress. Here are a couple of long abstracts on this topic:

http://www.lpi.usra.edu/meetings/lpsc2008/pdf/1913.pdf

http://www.lpi.usra.edu/meetings/lpsc2010/pdf/2648.pdf

The second paper above makes the following observations on page 2 under Implications:

"In addition to the lack of fluvial features within the analyzed stratigraphy, the occurrence at the two latter locations outside of closed basins rules out lacustrine sedimentation as a formative process. Rather fallout of sediment from suspension in the atmosphere is a more likely origin, as has been suggested for similar deposits in eastern Arabia Terra. Such a process is consistent with the observation of bedding which can drape pre-existing topography such as crater walls in several of the locations."

So it can't be fluvial-lacustrine processes that have deposited these very regular layers, which for these authors leaves aeolian sedimentation as the only possibility. The wind does not usually create planar bedding, let alone repeated uniform planar bedding. Impact surge would be expected to drape pre-existing topography. Further, the spin-axis obliquity variations that seem to be the favourite choice for an astronomical "cycle" to correspond to the "cyclical" bedding are not actually thought to be a cycle at all but a chaotic non-repeating series. (As I understand it, the influence of Jupiter makes the calculation a "three body" problem and thus not predictable over long periods of time.)

From my perspective these authors are making the case for surge.

hortonheardawho


Posts: 3465

Reply: 112



PostPosted: February 13, 2010 3:37 PM 

sol 2151 enhanced contrast and color saturation MI 3D of impact melt??:

with a link to a "wiggle animation" version.

This looks more like what I would expect to see for an impact melt. The "blueberry bridge" is different.

But one can argue that there is a lot of chaos in an an impact - so almost anything is possible...

I hope all of the exposures in this sequence are downlinked. I would love to revisit Aloya when the original data is publically available in a year or so.

Barsoomer


Posts: 344

Reply: 113



PostPosted: February 13, 2010 5:38 PM 

The apparently elongated berry with a blue dot reminds me of the thingie that was poking out of the "popcorn" back at Endurance crater.

Serpens


Posts: 169

Reply: 114



PostPosted: February 14, 2010 12:06 AM 

Impact melt that forms a laminate embedding berries etc yet leaves the surface pristing...at how many GPa?

LWS


Posts: 3062

Reply: 115



PostPosted: February 14, 2010 8:34 AM 

Here's a mixed up composite of one of today's pancam images released by Exploratorium. Its unremarkable except that it shows very clearly the dust cover over the scene. It may be a useful technique to show dust and also some details in false colour of the objects in a MER pancam scene.

Original size here

Winston

hortonheardawho


Posts: 3465

Reply: 116



PostPosted: February 14, 2010 12:05 PM 

sol 2154 ( Feb 14, 2010 ) MI pan of rock Chocoloate Hills with links to location and 3D pairs:

Enjoy.

Kye Goodwin


Posts: 1166

Reply: 117



PostPosted: February 14, 2010 12:23 PM 

Serpens, re your 114, Thanks, I'm happy to have some company in my skepticism about Aloya's origin involving impact melting. These big blocks of broken bedrock like Chocolate Hills are likely the least altered (least fragmented) products of the event because they were near the surface and away from the center of what is now the crater, not in a position to acquire a coating of molten rock from the possible melt zone under the middle of the crater. I suppose one could argue that melted material was driven into bedrock fractures and solidified by cooling and then the blocks were thrown onto the rim with the melt still attached. This is a big stretch in my opinion, even without getting into all the similarities between Aloya and the many fracture fills we've already seen.

LWS


Posts: 3062

Reply: 118



PostPosted: February 14, 2010 5:10 PM 

Hort; Re your #116. Some preliminary observations on the berries in the 3D anaglyphs. Hardly any wind tails seen so this area seems to have been protected somehow from wind. Could this suggest that there might not have been a long time between the impact and the present (as compared with berries on evaporite on other sites)? for the wind tail effect to manifest? Or Could impact melt have hardened the surface and thus restricted later wind erosion? Some Berry stalks separate and distinct from wind tails seen. Also, what might be broken stalks are seen and what might be a curved berry stalk seen.

Hope they do another one in the area where distinct long berry stalks can be seen.

Good image as usual. When is the colourized version coming out?

Winston

serpens


Posts: 169

Reply: 119



PostPosted: February 14, 2010 6:49 PM 

Kye Goodwin - I agree.

Hortonheardawho, thank you for the image at reply 116. Most interest has been focused on the embedded berries, but it is the associated rock surface that will reveal the diagenetic history. Unlike Eagle and all subsequent exposed bedrock this is a recently (in geological terms) exhumed sample. Bill and Ben, could you give a reality check here because I think I can see small scale crystal molds, re-crystallization around berries and an empty re-crystalisation socket without berry. Possible veins and small vugs. All indicative of recharge after the original formation of berries. Or maybe I am seeing what I want to see.

But if this was impact melt we would not be seeing such a clean fracture with minor weathering. The lack of eolian weathering may only reflect that the fracture side was hardened through the fracture fill deposition process and resisted weathering compared to the other exposed areas.

Ben


Posts: 2270

Reply: 120



PostPosted: February 14, 2010 7:49 PM 


1. Isn't the fracture fill only 0nly the dark material at the top of the image which casts the shadow with a hole in it?

2. Many of the berries have a granular surface.
Is it because they haven't been exposed long enough to
acquire shiny (Desert Varnish) ?

3. Are the dark specks in the matrix, crystals or mineral grains?

4.The berries in the horizontal crack don't appear to have formed their but have been recently trapped.

5. The surface should show the alternating hard/soft layers. Could thir absence be due to hardening of this fracture surface?

6. I can't determine where this image is located but it would be helpful to see a close-up of a berry engulfed by the fracture fill to examine their relationship.

7. And last but not least we are fortunate to have someone who prepares these images fo us. Wink

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