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Victoria Annulus, Discusions about Victoria's Apron
RNeuhaus
post Aug 9 2006, 01:41 AM
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From today, Oppy will start to head toward the Victoria Crater which is about 500 meters away. The drive would take about one month (that is 15 soles of driven with an average of 33 meters/sol, the other 15 soles would be for other purposes or restrictive soles).

The surface around Victoria Annulus, I seems it won't be as smooth as the way between Eagle and Endurance craters but the surface would have no uniform or parallel wave of sand and dust in small size of ripple. See Phil's Victoria Annulus partial map, Tesheiner's one Victoria Crater picture

Otherwise, the surface might have ripples smaller and alike to the ones of El Dorado, on the skirt south side of Columbia Hill. Besides, the Anuulus has no outcrops except to around of few small mini-craters.

This is a change of morphology of surface around the Victoria Annulus. What does it explain about this developing kind of surface of sand? Its extension is just around the inside of Victoria's ray of ejection. That is coincidence. Around that has no bigger ripples as the outside of Annulus.

The explanation would be that around annulus has smoother rock or outcrop surface, no blocks which had not helped to build ripples by the winds. Other factor, I am not sure, is that the slope from the border of Annulus to crater is positive (going up by few meters), then this might be another factor not to build ripples. I have seen that anywhere in the desert that have a slopes does not have any ripples but only flat surface.

Any debate about why the Victoria Annulus does not look like ripples as the outside of Annulus.

Rodolfo
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dvandorn
post Sep 17 2006, 06:16 AM
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The "Hershey's kiss" berries in this MI view are not only conical, the cones are slightly faceted. However, I still have a hard time believing that this is due to aeolian erosion.

My main objection to this being aeolian erosion is that, if these kisses are hematitic concretions that have been eroded out of evaporite from Victoria ejecta, they ought to have been emplaced on the surface (and thus exposed to winds) *after* some, if not most, of the blueberries out on the plains. All other things being equal, the berries on the plains, having been exposed to winds for a longer period of time, ought to display a greater degree of erosional faceting.

They don't. In fact, the blueberries seen in the soils out on the plains (and in both Eagle and Endurance, for that matter) were remarkably spherical. I don't remember seeing a single concretion, up until this last series of MIs in the Victoria ejecta, which displayed obvious ventifact forms. These are the very first examples of this type of morphology in the blueberries (if that's what they are) that I can recall.

Of course, the key to the above statement is "all other things being equal." If these are acutally hematitic concretions, they would seem to have eroded out of Victoria ejecta made up of concretion-bearing evaporite, correct? But evaporite emplaced this close to the rim of a crater this big must have been awfully shocked. What do berries which erode out of *highly shocked* evaporite look like? Maybe they look like Hershey's kisses...

One thing bothers me, though. We're only 120 meters away from the rim of a crater that was created in an enormous translation of kinetic energy into thermal energy. It was big enough to dig a crater that was, originally, probably at least a half a kilometer wide and several hundred meters deep.

I have a hard time imagining how the ejecta emplaced only a couple of hundred meters, at most, away from the edge of the hole made by this powerful explosion could have been so relatively unaltered that it would look even remotely like the evaporite we saw out on the plains. If, in fact, these berries are hematitic concretions which formed exactly the same way those out on the plains formed, and if they were originally formed in the target rock into which the Victoria impactor struck, why have so many of them survived seemingly intact (if mysteriously eroded into little cones)?

And if the "kisses" are the same size as the concretions we saw out on the plains, then what are the mostly spherical bodies which, except for size, closely resemble the mostly-spherical plains berries? Are these also concretions? If so, why are they fairly uniform in size but only a fraction the size of the plains concretions? And if the kisses and smaller, rounder bodies are both concretions, why do they both exist? We're not seeing spectrum of sizes, here, that would suggest the result of erosional or shock processes -- we're seeing a small population of kisses, and much larger population of fairly uniformly-sized smaller, rounded bodies. Such a neat division of populations suggests differences not in erosional processes, but in formative processes. And in composition. In other words, I think it makes more sense to assume that the kisses and the small spheres have different compositions and/or formation histories.

Ah, but if only one of these two populations is made up of hematitic concretions, which one is it? Perhaps there is a clue in this most recent MI image -- there is a feature in the dust "above" the rock face that looks rather like a worm. But this 'worm' is exactly the same size, in planform, as the small spheres. It resembles the small spheres in almost all respects, except that it is a drawn-out blob instead of a spherical blob.

Perhaps this would suggest that it is the small spheres that were once molten? I can visualize a spray of impact melt droplets solidifying into spheres in the very thin air as they flew out of the crater (not enough air pressure to compress them into teardrop shapes), and that while most of them fell as individual, rounded drops, some of them would hit each other in mid-air and form into, among other forms, chains of drops that ended up looking like tiny little worm-forms.

In other words, could the small spheres be the impact melt we've been looking for?

One last thing -- this all assumes that the annulus we see around Victoria is primarily the erosional remnants of her ejecta blanket. However, if Victoria is indeed a once-covered-over crater that has been (or is being) exhumed, then the soil we're looking at maybe doesn't incorporate much at all from the original ejecta. Maybe we're just looking at the erosional remnants of the materials that covered Victoria, and its actual ejecta blanket is still buried and inaccessible to our eyes? Of course, if that's the case, you would expect these soils to look exactly like any other patch of blueberry-paving in Meridiani, and it most definitely looks different from the plains soils. So I tend to discard the once-buried-now-exhumed crater theory. (Besides, it looks like a sharp, fresh crater -- most of the exhumed craters I've seen on Mars look far older and more eroded than this.)

Well, that's my two cents worth, anyway... smile.gif

-the other Doug


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Pando
post Sep 17 2006, 06:42 AM
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QUOTE (dvandorn @ Sep 16 2006, 11:16 PM) *
Perhaps this would suggest that it is the small spheres that were once molten? I can visualize a spray of impact melt droplets solidifying into spheres in the very thin air as they flew out of the crater (not enough air pressure to compress them into teardrop shapes), and that while most of them fell as individual, rounded drops, some of them would hit each other in mid-air and form into, among other forms, chains of drops that ended up looking like tiny little worm-forms.

In other words, could the small spheres be the impact melt we've been looking for?


Interesting, but there is one piece of evidence that shoots this down. The perfectly spherical hematite spherules were found embedded between various layers of bedrock at Eagle and Endurance. This can't be explained by impact melt since the spherules were still in their original strata.
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Posts in this topic
- RNeuhaus   Victoria Annulus   Aug 9 2006, 01:41 AM
- - Analyst   QUOTE (RNeuhaus @ Aug 9 2006, 01:41 AM) F...   Aug 9 2006, 06:46 AM
- - djellison   Indeed -there is intended investigation of the thi...   Aug 9 2006, 07:06 AM
|- - RNeuhaus   QUOTE (djellison @ Aug 9 2006, 02:06 AM) ...   Aug 9 2006, 02:08 PM
|- - Nirgal   Re. the Apron/Annulus: Apart from the orbiter imag...   Aug 10 2006, 06:40 AM
- - WindyT   Let's not forget the slightly arcane math ques...   Aug 13 2006, 04:56 PM
|- - algorimancer   QUOTE (WindyT @ Aug 13 2006, 11:56 AM) Le...   Aug 13 2006, 08:22 PM
- - dvandorn   It's also very difficult to estimate the amoun...   Aug 13 2006, 09:33 PM
|- - WindyT   QUOTE (dvandorn @ Aug 13 2006, 09:33 PM) ...   Aug 14 2006, 03:43 AM
- - Bill Harris   You are correct, without topo and gridding data/ca...   Aug 13 2006, 10:08 PM
- - Bill Harris   Here are initial (and very WAG) guesses on the vol...   Aug 14 2006, 09:08 PM
- - dvandorn   And, like I said, Bill, the composition of the imp...   Aug 15 2006, 06:45 AM
- - Bill Harris   Oppy is currently in the transition zone between t...   Aug 16 2006, 06:14 PM
- - djellison   Wow - nice MI sequence.....trying to merge with Pa...   Aug 16 2006, 07:50 PM
|- - RNeuhaus   QUOTE (djellison @ Aug 16 2006, 02:50 PM)...   Aug 16 2006, 08:06 PM
|- - Tesheiner   QUOTE (djellison @ Aug 16 2006, 09:50 PM)...   Aug 16 2006, 08:08 PM
|- - Nirgal   QUOTE (djellison @ Aug 16 2006, 09:50 PM)...   Aug 16 2006, 09:29 PM
- - djellison   I don't believe any placement info for the MI ...   Aug 16 2006, 09:09 PM
- - dvandorn   I would be really interested in seeing the mini-TE...   Aug 17 2006, 12:01 AM
- - Bill Harris   Here is the current PanCam view of the sand at our...   Aug 21 2006, 05:44 PM
- - hortonheardawho   4 frames of sol 910 MI pan near Mossbauer press co...   Aug 21 2006, 08:01 PM
- - Bill Harris   Whew, who said flat as a pancake! Here is an ...   Aug 21 2006, 10:40 PM
|- - mhoward   QUOTE (Bill Harris @ Aug 21 2006, 10:40 P...   Aug 21 2006, 11:12 PM
- - djellison   That's several sols old.... Sol 912 - 10:38am...   Aug 21 2006, 11:05 PM
- - Bill Harris   Well, duh. You're correct; I was thinking tha...   Aug 21 2006, 11:26 PM
- - CosmicRocker   When I saw that sol 912 L7 during my morning MMB u...   Aug 22 2006, 04:23 AM
- - mhoward   A quick stitch:   Aug 22 2006, 05:04 AM
- - Bill Harris   In the lastest Navcam pans, we can see a light-ton...   Aug 24 2006, 01:47 PM
- - jamescanvin   Just been looking at the tracking site for tosol (...   Aug 25 2006, 01:56 AM
- - Tesheiner   > Does anyone know if Oppy has done any (intent...   Aug 25 2006, 06:12 AM
- - Bill Harris   It gets more interesting on the ejecta apron. Loo...   Aug 25 2006, 12:57 PM
- - RNeuhaus   The surface is so "ironed". Very plane a...   Aug 25 2006, 02:31 PM
- - Bill Harris   Here is an L257 Pancam of the spot that Oppy trenc...   Aug 25 2006, 11:08 PM
- - RNeuhaus   This kind of surface is very easy to drive as off-...   Aug 26 2006, 12:04 AM
- - Bill Harris   I'm thinking that one sub-cycle of the Martian...   Aug 26 2006, 01:40 AM
|- - Aldebaran   QUOTE (Bill Harris @ Aug 26 2006, 01:40 A...   Aug 26 2006, 03:10 AM
- - CosmicRocker   Well, all I can add to this discussion is that I w...   Aug 26 2006, 06:02 AM
- - Bill Harris   Aldebaran, your analysis is correct, I was having ...   Aug 26 2006, 09:34 AM
|- - ElkGroveDan   QUOTE (Bill Harris @ Aug 26 2006, 01:34 A...   Aug 26 2006, 02:48 PM
- - CosmicRocker   QUOTE (RNeuhaus @ Aug 25 2006, 07:04 PM) ...   Aug 27 2006, 06:31 AM
- - Bill Harris   This is indeed the beauty of having a continuous o...   Aug 27 2006, 09:25 AM
- - Bill Harris   The first MI images of the ejecta apron beyond the...   Aug 31 2006, 03:38 AM
|- - Gray   QUOTE (Bill Harris @ Aug 31 2006, 03:38 A...   Aug 31 2006, 04:50 PM
- - glennwsmith   Bill, one never knows where to post. Re the MI im...   Aug 31 2006, 03:51 AM
- - Bill Harris   Well, maybe, technically, but let's look at th...   Aug 31 2006, 06:45 PM
- - Gray   I agree with your prediction that the evaporite is...   Aug 31 2006, 07:41 PM
|- - Nirgal   Here is a panorama of the latest MI in false color...   Aug 31 2006, 08:49 PM
|- - ugordan   QUOTE (Nirgal @ Aug 31 2006, 09:49 PM) He...   Aug 31 2006, 09:04 PM
|- - RNeuhaus   QUOTE (Nirgal @ Aug 31 2006, 03:49 PM) He...   Sep 1 2006, 01:12 AM
- - Jeff7   I find it interesting that so many of them seem to...   Sep 1 2006, 03:17 AM
|- - tty   QUOTE (Jeff7 @ Sep 1 2006, 05:17 AM) I fi...   Sep 1 2006, 06:51 PM
|- - BEHSTeacher   QUOTE (Jeff7 @ Aug 31 2006, 11:17 PM) I f...   Sep 1 2006, 07:35 PM
|- - SacramentoBob   QUOTE (BEHSTeacher @ Sep 1 2006, 12:35 PM...   Sep 2 2006, 05:50 PM
|- - Aldebaran   QUOTE (SacramentoBob @ Sep 2 2006, 05:50 ...   Sep 10 2006, 03:49 AM
- - glennwsmith   Fantastic colorization Nirgal!   Sep 1 2006, 04:17 AM
- - centsworth_II   Thanks Nirgal, I now have a life-size bit of Mars ...   Sep 1 2006, 05:40 PM
- - Gray   Very impressive Nirgal. What caught my eye was, j...   Sep 1 2006, 06:44 PM
- - gregp1962   Um, where are we? http://qt.exploratorium.edu/mar...   Sep 2 2006, 06:04 AM
|- - bluemars1   QUOTE (gregp1962 @ Sep 1 2006, 11:04 PM) ...   Sep 2 2006, 06:16 AM
- - MizarKey   Greg, that image, for me, was immediately recogniz...   Sep 2 2006, 08:08 AM
- - RNeuhaus   The microcospic picture taken on scrapped track. I...   Sep 2 2006, 06:16 PM
|- - algorimancer   QUOTE (RNeuhaus @ Sep 2 2006, 01:16 PM) T...   Sep 2 2006, 09:09 PM
- - djellison   It's soil pushed flat by the mossbauer. Doug   Sep 2 2006, 09:15 PM
- - glennwsmith   I hate to keep obsessing about this bit of conchoi...   Sep 3 2006, 04:26 PM
- - RNeuhaus   Gleenwsmith: The stone is the original comparing ...   Sep 4 2006, 04:59 PM
- - glennwsmith   Rodolfo, I am certainly agreeing with you if you a...   Sep 5 2006, 03:49 AM
- - dvandorn   I keep wondering if the specific forms we see in t...   Sep 5 2006, 06:28 AM
- - Bill Harris   Finally, we got the makin's for L257 images of...   Sep 9 2006, 10:19 AM
|- - john_s   I couldn't resist this comparison:   Sep 10 2006, 02:59 AM
- - glennwsmith   john s -- sweet!   Sep 10 2006, 03:04 AM
- - CosmicRocker   That was freakin' brilliant! It is no...   Sep 10 2006, 03:41 AM
- - CosmicRocker   I've gone over all of the recent MIs and I can...   Sep 10 2006, 06:31 AM
|- - Aldebaran   QUOTE (CosmicRocker @ Sep 10 2006, 06:31 ...   Sep 10 2006, 06:54 AM
|- - dvandorn   QUOTE (CosmicRocker @ Sep 10 2006, 01:31 ...   Sep 11 2006, 01:45 AM
- - Bill Harris   "Tektites" or "impact lapilli...   Sep 10 2006, 11:49 AM
- - Bill Harris   Here are the latest color Pancams from the current...   Sep 10 2006, 01:16 PM
- - CosmicRocker   Doug: I don't have a problem with the term te...   Sep 11 2006, 04:36 AM
- - CosmicRocker   QUOTE (Bill Harris @ Sep 10 2006, 06:49 A...   Sep 11 2006, 06:00 AM
- - Bill Harris   OK, then explain what we're seeing on the ejec...   Sep 11 2006, 10:34 AM
- - Gray   I think Bill might be on the right track. Look ag...   Sep 11 2006, 02:00 PM
|- - dvandorn   QUOTE (Gray @ Sep 11 2006, 09:00 AM) I th...   Sep 11 2006, 03:30 PM
- - CosmicRocker   Thanks Gray and dvandorn for the image and the des...   Sep 12 2006, 05:28 AM
- - Bill Harris   That is what is puzzling about the larger "He...   Sep 12 2006, 11:15 AM
- - Floyd   If the "Hershey's Kiss" spherules ar...   Sep 12 2006, 12:05 PM
|- - RobertEB   QUOTE (Floyd @ Sep 12 2006, 07:05 AM) If ...   Sep 12 2006, 12:27 PM
- - Indian3000   CAHVOR color projection L257 R = 80% L2 + 20% L7 ...   Sep 12 2006, 05:02 PM
- - Indian3000   R = 100% L2 G = 100% L5 B = 100% L7   Sep 12 2006, 05:05 PM
- - Ant103   Wow! Delicious colors on the first pic Indian3...   Sep 12 2006, 07:21 PM
- - Ant103   I made a crossed-eyes (or parallel what is the ...   Sep 13 2006, 04:37 PM
- - Gray   Cosmic Good job on the anaglyphs of the pebbles....   Sep 13 2006, 04:44 PM
- - CosmicRocker   Indian3000: That is very nice color, and thanks f...   Sep 13 2006, 07:02 PM
- - Bill Harris   Here is an L257 Pancam of what I suppose to be the...   Sep 15 2006, 04:57 AM
- - Stu   Nice berries...   Sep 15 2006, 05:48 AM
|- - Marcel   QUOTE (Stu @ Sep 15 2006, 05:48 AM) Nice ...   Sep 15 2006, 06:51 PM
|- - Pavel   QUOTE (Marcel @ Sep 15 2006, 02:51 PM) Se...   Sep 15 2006, 09:02 PM
- - CryptoEngineer   JPL just released this (rather grainy) photo of a ...   Sep 15 2006, 06:25 PM
|- - volcanopele   QUOTE (CryptoEngineer @ Sep 15 2006, 11:2...   Sep 15 2006, 09:29 PM
- - Bill Harris   Here is an MI of part of the Cape Faraday rock fro...   Sep 17 2006, 12:43 AM
- - dvandorn   The "Hershey's kiss" berries in this...   Sep 17 2006, 06:16 AM
- - Pando   QUOTE (dvandorn @ Sep 16 2006, 11:16 PM) ...   Sep 17 2006, 06:42 AM
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