Interesting blocky feature visible in the latest navcams (centred in this crop):
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I've identified it orbitally - it's the block marked with the black arrow in this crop:
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It appears to be at the exposed end of - dare I say it - a linear feature marked with white arrows in that crop.

Good observation noting the apparent linear feature. I'll withhold comment for now ...

That big block looks like it's in the brecciated zone. I wonder if it's just a mega-sized fragment in the breccia.

It's a little tough to say whether the feature in question is linear or arcuate, though I admit it looks more linear to me. (If it's arcuate, it's not really concentric to the impact point, is it...?)

-the other Doug

Looking at the features along this portion of the rim a little more carefully, I get a gestalt impression of the entire landmass that contains the current capes and bays having slumped down fractures as the pressure of the mass in the rockbed has decreased as the rockbed has descended into the crater pit.

Look at it this way -- the Guam area, and the area along this new linear feature, are all places where the land between the feature and the rim of Victoria has slumped down a bit, a few centimeters here and there. No more than half a meter, I'd bet, anywhere along the line. Now, these may have been impact-created fractures or they may have been pre-existing, but as mass was removed from the rockbeds between these fractures and the rim of the crater, the entire rockbled has slumped along these fracture lines. Leaving these little ridges that we're seeing, here.

Looking at it, my first impression is that the Guam formation represents slumping along an impact-generated fracture, while this linear feature is along a pre-existing linear fracture within the rockbeds.

-the other Doug

While waiting for today's batch of images from Opportunity, just tell that the next cape clockwise (C3) has been named Cape of Good Hope.

Sol 1096 images are downlinked and available.
Here is a three-frame navcam mosaic looking east and covering Bay C3, Cape of Good Hope (C3), Bay C5, and Cape D1.
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Edit: I'm wondering if we would have a chance to "snif" the bright layer of bedrock --the first layer right below the jumbled ejecta-- we have seen on all (?) bays and capes since Duck Bay. It looks like that layer might be accessible at the tip of cape D1 or perhaps the one following D1.

Quick close-up...

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Cape of Good Hope(C3) and Cape D1 look like they were uplifted during the impact -- more so than some of the other capes we've seen to date. Very interesting stuff.

(Feel free to move this to a new cape thread)

This sounds very like what I have been suggesting for some time. Just add one ingredient - a buried layer of highly hydrated material that got fluidised by the impact shock.

I'm curious where you heard this Tesheiner?

Is anyone else curious about that lump on the next cape. It looks like an intact out crop where I would expect jumbled ejecta.

ed

Its a very interesting lump indeed. Perhaps a single large block of ejecta that has resisted erosion, or come from another impact?

The dark material at the base of the eastern capes is getting more interesting as we get closer. It seems to be associated with a specific layer in the section which is perhaps more fully exposed along the northeastern extent of the crater edge. Maybe it is a blueberry rich seam?

Elementary, my dear Watson!
Among the planned imaging sequences for tosol (1096) was this one:

01096 p2373.10 16 0 0 16 2 34 pancam_cape_good_hope_longbaseline_L257R2

You can see the Lump of Good Hope in the attached image cropped and up-sized from the original MRO shot. It does seem quite out of place and is possibly associated with an east northeast-trending fault. I hesitate to call it that because all I see is the barest indication that there may be a fault which has created some elevation differential leading to the abrupt edge of the dunefield to the north. There seems to be a depression to the east of the lump as well but I can't pick this out from the navcams mosaiced above.

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I laughed at first because I was thinking how odd it would be for a fault to show through that ejecta debris, but I'm a believer of sorts now. If that is a fault, it would show in the bay, and if it shows in the bay, what would it look like?
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No smoking gun, but there does look to be a mismatch in that white layer where I've put the purple hint

When I first posted on the blocky feature (I love the name Lump of Good Hope!) yesterday, I pointed out the linear feature but dared not utter what thoughts were stirring under my scalp. We just had the announcement of allegations that we have linear "ridges that may be fractures surrounded by chemically cemented sedimentary bedrock" on the rim of Victoria. Could the Lump be an exposed piece of that "chemically cemented sedimentary bedrock" along the "fracture" I indicated?

Man, I can't wait for pancams, and the Lump looks like it should be accessible quite easily to Oppy from above!

Good observation, Tesheiner. Actually, if you look back at images of Cabo Corrientes from Desire (sol 1073 or so) it looks like the white layer is very close if not accessible at the outermost parts of Corrientes from the surface. Also it looks like Hoy is capped with the white layer. They really should've considered driving onto Hoy!

The "Lump of Good Hope"?!?!?! Man, and people laughed at the "Ultreya Abyss"...! Actually, I think that's a cool name. And someone who nicknamed a feature after an animated dragon in a kids tv show can't throw stones can he..?

Had a go at a 3D...

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Note: I started a dedicated "Lump" thread, if anyone wants to start discussing this feature there..?

Seems like a lot of interest in this newly-spotted feature, so I'll start a dedicated thread. One of The Powers That Be can always close it down if it's deemed unworthy...

So, any comments, suggestions, etc? Here's a question for you - how come it's so flat on top?

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Seems like a good idea to me but perhaps one of the 'powers' could move the relevant posts over here since quite a lot of exciting things have already been said. If it is a fault - or fracture - I wonder if there is any sign of its continuation roughly where we are now?

Good idea to start a new thread on this.
Have a look to the "crack" (or whatever you should call it, I'm not a geologist) highlighted on the image below. It looks like two channels converging to a single one. It doesn't looks like those fractures usually created by termal cycling but it reminds me of something created due to fluid flow.
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Comments?

What look like cracks could be narrow "spills" of dust as we've seen on other rocks. Any idea what the plans are regarding pancam imaging?

[EDIT: Your wish has been granted ]

Mars Rover transform in this image to Transformer Opportunity

http://qt.exploratorium.edu/mars/opportuni...TVP1151L0M1.JPG

Onto Cape Good Hope and more Capes to Come.

The lump appears to be either the largest ejecta block we have encountered so far, or a block of the cemented ejecta layer that has broken free and slipped down from a position just above. I wish those pancams would come down.

Long baseline navcam views of the Lump, sols 1095 and 1096, cross and anaglyph:
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The lighting is very different on the two sols.

After looking at the anaglyph I'm not sure if I'm seeing one lump or two.

Me neither. It almost looks like a spit pointed directly at Oppy in this view, unless the Lump is in fact completely detached from the background portion.

Hehe...one lump or two, or three? This thing has turned out to be more interesting than I imagined it would be. It's great that we have a new mystery, considering how slowly the images are coming down. The pancam thumbnails apparently came down with a previous batch, but as I write this, the full frames are not listed as downlinked on the tracking site, yet.

If I am reading the consensus here correctly, the three possibilities are that the lump is: a block of resistant ejecta, a spit or extension of the Cape of Good Hope into the bay, or a section of the upper layer of cemented ejecta that has broken off and fell down to its current position.

After studying the navcams more carefully, I am putting my money on the third option. I selectively stretched the contrast of the lump, the cliff behind it, and the little lump at the bottom of this image, and I am convinced they are all comprised of cemented ejecta. The navcam LBL stereo imagery provided by fredk convinced me that this block has detached and slid/fell/slumped from above. I think depth perception is going to be critical here. The yellow arrows in this image indicate one possible path the lump might have taken. I tried to make some supporting measurements with AlgorimancerPG. It seems that the lump might fit if returned to my proposed position, but I am not prepared to publish that data, yet.
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[quote name='WindyT' date='Feb 23 2007, 07:16 PM' post='84392']
If that is a fault, it would show in the bay, and if it shows in the bay, what would it look like?
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The orbital view shows that a linear feature also exists on "our" side of the bay, albeit different in appearance. It broadly aligns with the crest of the Lump, and is marked by a shadow line. It will be interesting to look back at it when we get over to the Cape of Good Hope.

There were two imaging sequences taken on sol 1097 (pancam, all filters) named for spanish regions: Madrid & Alava.

01097::p2579::17::13::13::0::0::2::28::pancam_madrid_L234567Rall
01097::p2580::17::13::13::0::0::2::28::pancam_alava_L234567Rall

Just have a look to what I've found on the tiny thumbnails.
Here is the first thumbnail, corresponding to Madrid; it looks familiar, doesn't it?
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after seeing fredk lbl (thanks for that), it seems that there is a significant under side that is exposed. I'm pretty sure this is, by far, the largest sheltered area we seen.

ed

Another possible lump? I'm beginning to think they are ejecta blocks... The post drive navcams on sol 1100 seems to indicate they are not targetting the lump.

ed

Maybe. Although the navcams are centered at 180º (i.e. south), the post-drive pancams are centered at SW. My impression is that they are still focusing on taking some shots of Cabo Corrientes from a point nearby the lump.

I've been assuming that everything above the light colored stripe is ejecta that rained down after the blast that formed Victoria, and this 'Lump of Good Hope' seems to be above that line. Some of you folks with much more geology experience than I've got (I can usually tell a rock from a brick) are saying that the LOGH might be cemented ejecta that has slipped. That sounds OK to me, but it makes me wonder what made it cement together in such a uniform way when all the other ejecta has lots of descrete chunks embedded. I'm open minded about this, so answering is worth while, but to me it looks like this is a very large single lump that held its integrety during the crater formation process.

antoniseb,
Your question is very appropriate. The LOGH could be just a VERY large fragment that was deposited along with all the other smaller fragments in the breccia.

I'm not sure I'd use the term "rained down," here. I think "surged onto" is more appropriate, this close to the cratering event. It makes a difference when you try to envision the dynamics that emplaced the ejecta layer.


While the dynamics of the ejecta surge around a cratering event can be well-described in aggregate, the conditions at any given point in the surge tend to be chaotically dynamic. Pockets of gas, pockets of vaporized volatiles (such as water or water ice), layers of soft rock underlying layers of harder rock -- all of these things cause localized discontinuities within adjacent parts of the surge flow.

That's all a rather long-winded way of saying that conditions can be just right to cement some large blocks of ejecta, while adjacent portions of the flow can consist of far more shattered blocks of rock. It's also possible for surge conditions to favor the ejection, whole, of some large blocks of pre-existing rockbeds while all around these large blocks you find far smaller, shattered pieces.

In other words, the conditions in the local ejecta surge around a cratering event could account for the LOGH to be either cemented ejecta (i.e., a breccia of some sort) or an intact block of rockbed. So, in this case, theories aren't enough -- we need (hint, hint) to go take a close look at it (hint, hint) to determine the truth either way (hint, hint).



-the other Doug

I had the impression that the immediate goal was to find a clean exposed accessible deep cliff so we can examine the chemistry of the layers as they get deeper down. Perhaps looking at the LOGH would be a good scond mission if Opportunity can climb out of the crater at it's first entry point.

Here's the sol 1100 pancam view of the top of the Lump, heavily stretched because of the afternoon lighting:
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And the corresponding anagram:
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The top of the Lump is the farthest part of the foreground surface, between centre and right edge.

Apart from Lumpiness, this is a spectacular image! Behind the Lump we have Cabo Corrientes. Immediately behind that, jutting about a third of the way in from the right, is Cape Desire. Behind that, Cabo Anonimo, and behind that, Cape St. Mary rising up to the Beacon at the highest point. I'm quite sure that behind that is Duck Bay, though we can't quite see our entry point yet.

Whew, that's quite the stretch of Victoria's drive foreshortened into one pancam frame!

That is *quite* a dramatic view - worthy of a post card.
I also noticed that the breccia on this side of Cabo Corrientes also looks to be quite lumpy. That is, the fragments in the breccia look much larger than they have in other places.

The view from Good Hope.


And the traditional desktop picture :

I'm a little surprised that there are no images of the apparent fault line running up to LOGH.

I was to see some images of the ?faulted? area too. The rear hazcam gives the only view of any spot near that area, but nothing obvious shows up. It's possible that it's a feature that is more obvious from above than at ground level.

PS Great views, Ant.

The sol 1100 navcams show the area of the "linear" feature. The route map shows that we were sitting right on the feature on sol 1100, and we look along it (so it's foreshortened) towards the southwest in these two navcam frames, which I've stretched quite a bit:
Click to view attachmentClick to view attachment
It looks like more of the same exposed rock to these non-geological eyes.

Absolutely beautiful, Ant103. I wish I could speak French to tell you how much I enjoyed your sol 1100 panorama. When I did my version it hurt me to destroy the mood by stretching the daylight out of those lovely, shadowed cliffs. But we so rarely get raws that can be contrast stretched as far as these could. The devil in me wanted to see the details in the rocks.

Doug: I thought your post was an excellent summary of many of the complexities that need to be considered. This thing still has me wondering. In the first navcam set it looks like a breccia, but in the next set it looks like a block of ejected bedrock. I think a "closer look" needs only to be the pancams already captured but not yet revealed. I worry that they might leave me eating crow.

Those pancams will eventually come down the pipe. Until then, here is a HiRise anaglyph of the vicinity that I was looking at tonight, in case it might be useful to someone. I'm still having fun with the raws, but enough already.
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Spectacular indeed.
About missing the entry point, it's almost there about 10 or 15 meters to the right, behind the beacon.
Here is a crop of sol 1100 pancam mosaic where I'm pointing to a little "bump" at the horizon right to the left of the beacon.
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That "bump" is the dune besides Sputnik. Here below are two navcam images, the first taken at Duck Bay during sol 952 and the second one taken on sol 957 while heading to the tip of Cabo Verde, both covering Sputnik and the dune.

fredk
Thanks for pointing it out. I was looking for a ridge when it turned out to be a swell.

Tom, I'm curious where you obtained that, or did you make it yourself? It would be wonderful to have a full crater stereo view of that quality.

Tesheiner: thanks for confirming that Duck Bay location! I look forward to seeing our entry point from across Victoria. Should be soon now.

http://hiroc.lpl.arizona.edu/images/PSP/victoria.html

I'm not so sure.
Oppy would have to drive to the tip of the cape --and I believe they won't do that-- and even in that case I think it wouldn't be enough because the point that is blocking the view is nearer to Duck Bay, not to here.
My guess is that we will have to wait 'till getting at C5 or better D1.

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fredk: It indeed is nice to have the whole crater in stereo at that resolution. The anaglyph I posted was compressed a bit to create a 30% smaller download. I was wondering if anyone would notice that it was of somewhat better quality than the officially released anaglyph (and what's with that purple?). I converted crops from two of the full res HiRise images to PNGs and built it in Photoshop. I keep the anaglyph in Photoshop's PSD format so I can easily adjust the registration between the layers, depending on the view I want to make. I don't recall whether I had to scale or rotate the images to match them up, but it wasn't terribly difficult. You could probably make your own easily enough.

I'd be happy to make that file or the individual layers available to you or to anyone else who is interested, but I don't know where I can find the server space it would require to host it/them. I think it is a bit large to email. The PSD file is 150 MB, but it would reduce to about 25 MB if I converted it to a full quality JPEG. If I force each layer a 10 MB file I think I could post them on space available to me, or I could email them. Suggestions?