South from the landing site, sols 72-237, Starting the science traverse Options

[tau]

The closest Mastcam Z image from sol 213 with 110 mm focal length missed the SuperCam RMI target from sol 214 by only a few centimeters

[serpens]

.....I'm sticking with my subaqueous sediment gravity flow/turbidite interpretation until I see something inconsistent.

Just for clarity Tim. You previously mentioned the delta front for gravity flow/turbide deposition. While these rocks tend to have moved around somewhat, given the apparent lack of dip, do you mean the delta toe? Apologies if I'm missing something obvious.

[tau]

Another SuperCam RMI from sol 214 with Mastcam-Z context from sol 213.
A two-step stereoscopic grain-size measurement gives a diameter of about 0.25 to 0.4 mm for the small visible grains (medium sand according
to the Wentworth scale) covering the plane between some coarse grains and irregularly shaped rock fragments in the SuperCam image.

[Bill Harris]

Another SuperCam RMI from sol 214 with Mastcam-Z context from sol 213.

What is that disturbance in the sand behind the scale bars? The Rover wheels haven't been there, nor has the instrument Arm. And Laser Zaaps! don't fluff up the soil like that.

Martian soil is generally interesting. We need kilograms of samples!

--Bill

[tau]

It was the laser.

[Bill Harris]

Interesting bit of information. I wasn't aware that the soil reacted like that to the Laser.
I recall that the drill cuttings at an earlier stop fused into glassy lumps. But that this soil reacts so strongly to the Laser's heat implies hydrated minerals which could suggest particular weathering processes.

--Bill

[tau]

Hydrated minerals are not required for this effect.
The SuperCam uses its laser, among other things, for laser-induced breakdown spectroscopy.
A powerful laser beam vaporizes a tiny target volume and converts it into plasma.
This acts like a small explosion sufficient to blow away surrounding particles.

[tdemko]

Just for clarity Tim. You previously mentioned the delta front for gravity flow/turbide deposition. While these rocks tend to have moved around somewhat, given the apparent lack of dip, do you mean the delta toe? Apologies if I'm missing something obvious.

No, I think you are more correct here. We've seen some of the later foreset successions in the cliff faces. If these beds are what I think they are, the subaqueous sediment gravity flows would have originated either as collapse of the mouthbars or lip of the delta, and then flowed down the foreset/delta front, to the toeset, and potentially out onto the lake floor. If the river inflow was dense enough, hyperpyncnal underflows (which are also sediment gravity flows) could also have generated similar deposits. The thin-bedded nature of the outcrops in question look to me like either toesets or parts of fans that would have been deposited outboard of the foreset/toeset strata.

[serpens]

A two-step stereoscopic grain-size measurement gives a diameter of about 0.25 to 0.4 mm for the small visible grains (medium sand according
to the Wentworth scale) covering the plane between some coarse grains and irregularly shaped rock fragments in the SuperCam image.

As far as I know we have not seen any large clasts in surrounding rocks and the rock fragments you note look like conglomerates consisting of small particles. The effect of the laser shots may indicate that there is a desert pavement effect here with the underlying particles extremely fine. Potentially fallout of suspended load in Tim Denko's deposition model. I wonder whether the small particle size indicates a lower energy flow than was necessary for the formation of the main deltas. Potentially transport and deposition in a drier period or even prior to the breach of the crater wall by the input rivers as water entered through fractures, undermining the wall. Certainly there is no possibility that the crater wall was overtopped.

[Ant103]

Sol 213 MastcamZ panoramic at 34mm. This is our parking spot during the solar conjunction. Including a dust devil

[tau]

Sol 213 Mastcam-Z with greatly enhanced colors and contrasts.
This would make a nice backdrop for the sand ships in Ray Bradbury's "Martian Chronicles".

[Phil Stooke]

Here is a nice mission journal from the Supercam team in France. There are a few target names in it which I am adding to maps.

Phil

https://supercam.cnes.fr/fr/journal-de-bord...ot-perseverance

[Phil Stooke]

And here:

https://fiso.spiritastro.net/telecon/Bapst-...wMaser_9-29-21/

is a presentation about Ingenuity with a PDF of slides and an MP3 of the talk.

There is a map with feature names, but it's barely legible. I can pick out a few to use. Can anyone figure out the name of the crater just south of the landing site?

Phil

[Phil Stooke]

With help from Mike I found this page:

https://rps.nasa.gov/resources/115/nasas-pe...dziilii-crater/

so there's another name.

Phil

[PaulH51]

Unless there is a large dark rock next to Ingenuity then its blades / shadow are also included in this crop from this HiRISE image https://www.uahirise.org/ESP_071077_1985