Very much so.
Please do NOT let Rui play with this rock/map

Wow...

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Discuss!

It's not such a fresh crater after-all, the protective coating is wearing off the debris.

A mechanically weak layered deposit, originally formed in a fracture, is falling apart now it's exposed to the surface environment. Age can't be determined from the appearance of the rock if we don't know its strength.

Phil

Some more colour and 3D views on my blog, here:

http://roadtoendeavour.wordpress.com/2010/...chocolate-hills

It looks as if a congregation of berries became cemented into the rind, almost like a clast? The upper portion looks as if large crystals formed, perhaps hinting at how long this vein formed under solution?

Could this be the "impact melt" the team referred to ?

They mentioned a dark crust that was potentially impact melt. I'm sure this is what they were referring to - the only other rock crusts around look very similar to this.

Do these closeups provide any hints about whether this is a filled fracture or impact melt? Obviously the IDD work will be important...

Stu, I think I can see North-Am... ahem... nevermind

Oh ! And I also see ... *please Ant, shut up !* :/

Hum…

So, the Sol 2147 pan, with Chocolate Hills at the "wheels" of Oppy

The multi-layered appearance would argue strongly against impact melt, but more seriously still, this is on a bit of Meridiani sandstone, not an exotic rock. Evaporitic deposits in a vein - an old fracture - make far more sense, especially since we've been seeing these vein-filling materials ever since Eagle crater.

Phil

Gentlemen, I think Stu means "Discuss of the shape of the coating that looks like an ancient map of Mars" (see previous posts)...but I might be wrong

Well, it rather looks like a prediction sent by Martians for our future : the Earth as seen AFTER a global sea level rise by global warming (America is at left and what's left of Europe on the right...)
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That was such a cute game xD.

And yeah, I think we'll stay here a bit. This rock seems to be crying out for attention.

Here's Ant's latest pan in a circular format.

Phil

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I still haven't forgotten the high-speed turtle.

--Greg

Okay, who wants first crack at this beautiful rock with their geology hammer and field magnifying lens..?

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A gentle whack and then turn through the pages of time.

I really like the way that the fissures on the sides stop at some of the layering. Those layers are just waiting to be pried apart with a chisel.

Quote Stu - Okay, who wants first crack at this beautiful rock with their geology hammer and field magnifying lens..?

Mud cracks?
the Earthly kind http://www.earthscienceworld.org/images/se...d%20Cracks#null
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First MI images are up at exploratoium ...
here is a very quick try of a 3D shape-from-shading DEM ... unoptimized and uncalibrated as I havn't used the method for MI/rock images before.
Not sure if this could be of any use geologically (*), I was just curious what it would look like :-)

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(*) probably more for entertainment: something like a fly-through video over MI rock images

Try comparing the technique to results in here - http://an.rsl.wustl.edu/mer/merbrowser/mer...al.aspx?rover=2 - to see how accurate it is.

Rather like this view... Oppy getting ready to get down to work!

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Lots more pics on my blog, if anyone would like a look...

http://roadtoendeavour.wordpress.com/2010/...hocolate-chunks

Or more properly, shrinkage cracks (of which mud cracks are probably the best-known terrestrial example). They can occur in many different rock types that have undergone bulk shrinkage owing to drying, cooling, or weathering (with leaching). They also occur in concrete.

-- HDP Don

The MI's are targetting a part of the "rind" (whatever it is). Here's the portion covered so far, roughly outlined in black on Stu's fabulous colour view:
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Basically, this gives us a closeup view of the western Canada portion of "North America". Excellent place to start.

On the other hand, according to this Martian map, it looks like a big chunk of western Canada/US is missing and presumably has slipped into the Pacific. Another "prediction"?

Hey, Fred, this is a highly impertinent request, but any chance you could throw a couple of your famous Shadow Men around Concepcion? That sense of scale you provide is a great thing. (But no pressure if you got things to do, man; I can definitely relate!)

"it looks like a big chunk of western Canada/US is missing "

It's the old 'Mer de L'ouest'. Must have been the old Admiral's inspiration.

Phil

Mosaic of some new MIs...

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Wow, the blueberries seem to be really concentrated though still embedded... a heavier cluster than any berry bowl we've seen ?

Easy to imagine actually standing there, next to these rocks, when you see a view like this...

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...The anatomy of a crack, and a very dirty one. Likely a result of dessication shrinkage and debris (mostly blueberries, plus general Martian dust) filling, with evidence of multiple episodes of some sort of degree of re-hydration cementing things a bit.
We see again how the passage of time preferentially concentrates the hematite nodules while the sulfur-salt-sandstone matrix is powdered and blown away.
The extreme friability and tiny particle size of debris powder of the Meridiani substrate create some interesting questions. We have seen dunes of the sulfur-salt stuff only on places like the rim of Victoria, where the rate of production and concentration of the sulfur-salt powder is relatively prodigious. Where does it go? Some ideas...
1) The Meridiani hematitie/sulfur-salt plains occur only on a small percentage of the surface of Mars. Its eroded dust thus becomes just a trace constituent of the general Martian dust. It is just diluted to near-invisibility.
2) The sulfur-salt dust could be a preferred nucleation site for precipitation. Snow nucleus. This would systematically remove it from the global dust inventory over time.
3) There could be some sort of very slow chemistry going on between these sulfur salts and the Martian atmosphere. This might also influence how it erodes. It could be driven by some trace atmospheric constituent or even solar/cosmic radiation side effects.

Anyhow, these are some thoughts that the Concepcion MI's have brought to mind. I don't have good access to journals (I do read articles I find out about, by the way) or daily bull sessions with grad students, or full access to all the results of the instrumentation, so maybe this has been covered already. This forum is my scientific coffee break, about all I have time for. I hope the working scientists don't take offense, and will be glad for the display of interest in the details of their work, and forgive the speculations-based-on-inadequate-data that come out of this forum.

yummy...baked blueberries?

Introducing the new "Chocolate Hills" bar... crammed full of tasty berries and covered in a delicious, dark crunchy coating...

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Rightmost block of Chocolate Hills as pancam anaglyph:
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Nprev, with some luck I may be able to coerce the Mystery Men to come out of hiding - they're remarkably shy, but all this talk of chocolate may help...

I love the way the random polygons on that rock fit themselves into a square. It reminds me of this:

http://images.google.co.uk/imgres?imgurl=h...t%3D36%26um%3D1

Hmmm....verrrry interesting.
Is this the first time we have seen blueberries so tightly packed within a lithifying (?) matrix? Most of the laminated sandstone around here has the concretions well and evenly spaced, as in the usual pattern of their in situ formation. I assume they cannot form in such a closely-packed pattern, so we must infer that they were eroded out of the laminated sandstone, collected together in a crack between blocks and then re-cemented by later fluid invasion of the crack. Is this final step a rare and localized event, such that we have not seen before on Meridiani? Does this region have an unusually lengthened diagenetic history? One which points to a wet period following blueberry formation and excavation? Some areas of the exposure seem to show where blueberries have fallen out, leaving an "egg-carton" like pattern in the matrix. Blueberries excavated for the second time in their 'lives'! How long was this part of Meridiani wet?

Always something new.

EDIT: Or could the local impact have played a role? C'mon, Don, are you taking the plunge?

If those are remnants of a fracture fill on the surface of the rock, maybe it was a fracture filled with loose berries which were then lithified by the fill material.

I'd say that's the most parsimonious explanation, $.02, (Don might disagree), but then why haven't we seen it before?
Could the crater here provide a more localized, recent mechanism to 'cement' the concretions?

In the latest update, they still refer to impact melt: But INAG (I'm not a geologist)...

I'd hesitate to rule out a role for impact being so close to the little crater, but probably not, other than excavation. "Wet" is a relative term, so a possible working hypothesis might involve the role of soluble salts plus fallen dust plus transient moisture/frost in creating a cement to hold the fallen berries together within an initially open fracture, before impact exposed the sample. That potentially gives us billions of years of daily and seasonal and epochal climate change to call upon to cement the berries, without having to call upon flowing or standing water, other than transient surface films. (Or impact; sorry, I didn't even stick my little toe in...)

Just an initial working hypothesis, of course. One possibility among many, including impact melting, especially given that moist salt mixtures must have quite low melting temperatures (i.e., be very easy to fuse into a cement). On the other side, if the rock were exposed to enough impact stress to fuse the salts, how on Mars did all the brittle berries survive intact? So I'd tentatively rule out impact.

I'd tentatively rule out large quantities of liquid water too, because everything remains so fine-grained. If salty water were standing or flowing in that crack for any length of time, we might expect to see visible salt crystals (or their ghostly imprints) lining it, or perhaps solution/recrystallization damage (i.e., disaggregation) or other visible alteration affecting the salty rock next to the crack. (Where salts are concerned, liquid water is powerful stuff!) Such evidence appears to be lacking.

That seems to leave a crack filled with fallen berries and salty dust and frost and transient moisture and time as the least unattractive hypothesis for cementation. So boring!!

--HDP Don

I was under the impression that the berries were not so brittle, especially when compared to the sulfate rock. I find it hard to imagine blocks of that fragile material traumatized enough to melt the surface while the block remains intact. Especially so close to the rim of such a small crater. This looks like a big thunk and a lot of little thuds.

It seems a bit of a knife edge to define an impact that would leave such a small crater and melt the surface of fragile sulfate ejecta blocks while leaving them intact, and not throwing them very far.

AHAAA! The penny drops...
The dollar drops...
The euro rises...
The moon is blue and Prof Don favors moist chemistry, whereas JPL favors "impact melt".
...anyway, Shall we then follow our JPL PI's and view the 'matrix' as the product of molten or vaporized impact material injected under high pressure into cracks in the bedrock, engulfing and entombing the berries within? Why haven't we seen it around any of the other craters we have surveyed? Is it a very short-lived material like a glass, which breaks down quickly ( i.e. in thousands rather than millions of years)? Should it have an exotic - partly extraterrestrial (Mars equivalent) - composition, which we can detect with the IDD? Can we see any other signs of this violent history? On the other hand, this IS a crater and there must be some violence involved!

Is Mars boring? Noooooo!

We have seen similar looking "rinds" before. IIRC, at Erebus, but also inside Victoria, eg check out this post. I'm sure others can recall other locations.

Rinds, yes, but matrices packed solid with blueberries?

(image links requested)

For every thousand times I wanna ask a question here, I keep mum 947 of 'em. This time I gotta ask one simple (set of ) Qs(hehe):

Have we come across an impact crater that shows an object hit a wet surface? We have hints of subsurface water ice from Phoenix, and from the deposits dug up by Spirit; do we have any similar hints from something like the blueberries or other facts gleaned from the rovers' studies of craters and ejecta thus far that establish an object "splashed down" on Mars?

Could Endeavour crater give us such tantalizing hints? Did Endeavour crater occur while Mars was wet enough to prove in a new way that there was surface water? Or, have we already established that scenario from other data?

Thanks, and again, I really love this site!

I thought I might have seen a glimpse of what you are talking about as I flipped through some of the recent MIs, but then I realized it was a case of inverted topography. MI imagery can sometimes trick your brain since the images are inverted. Note that the shadows imply a sun shining from the bottom upwards.

Yes, we've seen many examples of these rinds before, as Phil previously noted. But I am pretty sure we never saw a rind containing closely packed concretions as we observe them here. It seems easy to imagine eroded berries falling into a dessication crack and eventually becoming cemented by some fracture filling, if some water is available in some form. Dr. Burt makes a good point regarding the grain size of recrystallized salts.

I've been trying to imagine an impact process that could release concretions from the matrix and then allow them to concentrate in a bedrock fracture. If the impact generated enough energy to melt or vaporize sulphates, it seems that most of the released blueberries would be blown out of the fractures. However, I can imagine some berries getting concentrated at flow path choke points.

I guess we did. There are numerous indications Mars was wet.

(1) Mars loses water faster than Earth - its gravity is ~3 times weaker, and it has no strong magnetic field to keep solar wind away. Yet, it _still_ has a lot of water (as ice). This means that it had to have much more water in the past than it does now. More water -> more water vapor -> stronger greenhouse effect.
(2) Primordially, it had to have much more water per unit of mass than Earth had just because it formed in colder region of proto-Solar system.
(3) We have solid evidence of minerals and landforms which can form _only_ in liquid water.

Thanks for the response, Den. What you're suggesting is that we've proven Mars was once wet on the surface. Theory has it that Mars dried up to basically its current state billions of years ago, and all these craters we're seeing are from collisions that happened after it dried up. I'm wondering if we have a chance to find evidence that one of these big old craters splashed - not crashed - to the surface.

Wouldn't there be a different signature in the ejecta if an asteroid splashed down on a Martian lake/ocean, instead of crashing into a dried up lake bed?

Oppy didn't make it all the way to the bottom of Victoria crater; did we learn all we needed to learn by going 1/3 of the way down? Was Victoria a lake at one point?

When the object that created Victoria crater struck Mars, was there surface or subsurface liquid water (not ice)?

I guess an obvious place to look would be Gusev crater, which became a huge lake bed before Mars dried up. That object crashed or splashed into a wetter Mars.

Do a literature search on "rampart craters" -- these things have splashy-looking ejecta that most scientists think are the result of ejecta being entrained in mobilized groundwater (produced from ground ice melted by the impact), while others (mostly Pete Schultz) say you can explain them with atmospheric effects.

You want layers? We've got your layers right here...

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I wouldn't say Mars dried up, it froze. It looks dry because it's so cold but it's actually got lots of water.

Rinds - the first I think was in Eagle, and was called shark or something like that. Over near the Berry Bowl.

And we haven't seen this specific thing before because we never saw one of these filled fractures in the open before - they were just protruding from the eroding rock.

Phil

That's stunning, Stu!