The Top of Vera Rubin Ridge Part 1, Site 66-67, sol 1812-1943, 11 Sep 2017-23 Jan 2018 Options

[serpens]

I think we need to wait and see what this little fellow is made of. While there may have been a few kilometres of sedimentary material covering this area in the past there would not be anywhere near the heat or pressure necessary for metamorphism. Could the apparent veining on the sunlit side be an artefact of reflectance?

[PaulH51]

I think we need to wait and see what this little fellow is made of....

We now have the R-MastCam frames of the two interesting 1831 ChemCam targets:

[serpens]

Given that we are still on a slope climbing towards the top of the ridge and these probably bounced down from a higher level, it wouldn't surprise to find that "Black Reef" is a chip off the old block so to speak.

[algorithm]

Only two in the immediate vicinity? If they were tumbling from above, wouldn't there be more? Having said that I don't know what "the immediate vicinity" is . Certainly seems to me to be out of context with their current location, very interesting that one seems to be a 'longer baked, bigger version, more developed', call it what you will, version of the other. Perhaps one arrived at it's current location long before the other?
Geology....madness solidified, I don't know how you do it!

[HSchirmer]

Given that we are still on a slope climbing towards the top of the ridge and these probably bounced down from a higher level, it wouldn't surprise to find that "Black Reef" is a chip off the old block so to speak.

"Architecture is solid music" - von Goethe

"Geology is solid climatology" - me

[serpens]

I would amend that to read " Sedimentary geology is solid climatology" - you.
I was in fact mulling over the possibility that "Black Reef" parted from "Normandien" on the way down, along a fracture. We have seen a few instances of this with float. For example, this three piece jigsaw.

Attached thumbnail(s)

 

[PaulH51]

Arm/drill issues after placing a sample from Ogunquit Beach in CheMin prevented the drive on sol 1833. That presented an opportunity to take another look at Normandien with ChemCam in Passive mode. It also meant the rover acquired a set of NavCam images with the arm extended
MS ICE managed to assemble these three frames. 'Curiosity looking back at its path', I hope others will properly assemble these.

[Gerald]

We now have the R-MastCam frames of the two interesting 1831 ChemCam targets:
...

To my limited geological experience, this looks remotely reminiscent of eroded stalagmites. Clay-loaded cool liquid dropping on a warmer ground would dry rapidly, form uneven layers, and might form small drying bubbles by outgassing or boiling.
As usual in hugely underdetermined data sets, that's just one of an arbitrary number of options.

[Phil Stooke]

To add to the range of possibilities... it was suggested that these rocks fell down the slope from higher layers, but I would point out an alternative direction of movement - impact ejecta thrown up from the plains to the north, or even from much further afield. If the material was impact melt, solidifying in flight, the holes might be vesicles (bubbles). Not saying it has to be that, I just want to add to the confusion.

Phil

[jvandriel]

The Navcam L view on Sol 1833.

Jan van Driel

[PaulH51]

Drive of approximately 13.9m SSE (147º) on Sol 1834 (Oct 3, 2017) LINK
Very roughly processed and roughly stitched partial pan assembled in MS ICE using the L-NavCam's... Poor processing, but a great view

[Phil Stooke]

Sol 1834 Hazcams reprojected to find the location after the drive - not always good enough, but today they work just fine.

Phil

PS I just spent an enjoyable afternoon with ngunn, a very nice chat about all things UMSF.

[jvandriel]

The Navcam L view on Sol 1834.

Jan van Driel

[vikingmars]

On the latest NavCam pics, and due to the low opacity of the Martian atmosphere and our climbing the hills, we are beginning to see clearly some far horizon features (herewith a Sol 1834 pic).
Dear Phil, as our talented Cartographer-in-Chief, could you please give us your opinion with a location on a map ?
Thanks so much in advance

[fredk]

Those look like the same features Phil identified in this post.