Traverse to the Delta, sols 379-414, 15 Mar 2022- 21 Apr 2022 Options

[Phil Stooke]

Starting a new thread as we leave the landing site and start the drive around Seitah. It will probably be quite fast unless something interesting turns up in the ejecta of the craters along the path.

Here is a circular panorama for sol 379, already north of the landing site. Maybe there will be some drive-by shots of the landing site itself.

Phil

[tau]

97 new Mastcam-Z raw images of the delta from sol 306 just arrived.
Here are three of them, specially selected for the "inner sedimentologist" of Saturns Moon Titan, in a processed version.
A note for new visitors: the blue color of some of the stones in the images is due to color enhancement. In reality they are more gray or brownish gray.

[Saturns Moon Tit...]

97 new Mastcam-Z raw images of the delta from sol 306 just arrived.
Here are three of them, specially selected for the "inner sedimentologist" of Saturns Moon Titan, in a processed version.
A note for new visitors: the blue color of some of the stones in the images is due to color enhancement. In reality they are more gray or brownish gray.

Thank you for processing these images tau they're great!

I should say that I'm not a sedimentologist, I'm more trained in analysis of orbital imagery, but I did attend the rover sessions at LPSC this year and I'll be helping with Perseverance operations when I start my PhD this fall. At LPSC the expectation, from long-distance imagery of these very same outcrops, was that they would be pro-delta (lakebed, deep water) mudstones. This was on the basis of their horizontal bedding and position at the very base of the delta (unlike the delta scarp stuff above which is often steeply inclined and represents delta front sandstones).

I actually think these new images contradict that hypothesis. The first image shows a conglomerate slab including at least two boulder-sized clasts that resembles what we saw a few days ago, however it's not clear this outcrop is in-situ and it might have slid down from higher up. The second image however is clearly in-situ and I believe it does not show a prodelta deposit but rather a fluvial or delta front deposit. This is because there is large-scale truncation surfaces and seem to be pebble or cobble-sized clasts embedded within it, all of which is consistent with sandstone rather than mudstone. However some of the horizontally laminated intervals might contain muds and silts interbedded with sands. The third image is the most enigmatic and scientifically interesting. There is a weird large undulation, and I'm really not sure what it could be. But since there's no folding on Mars this must be some kind of sedimentary bedform. To the left, the inclination of the bedding appears alarmingly steep, but I suspect this is an illusion due to foreshortening/perspective. There is also an unusual lithology here, it could be a massive (internally structure-less) sandstone bed or perhaps the elusive mudstones, just laminated so thinly the resolution is too poor to pick it out.

This has implications for the future of the mission. The idea that Perseverance would be able to access prodelta mudstones is kind of the whole reason the rover was sent to Jezero, because those clay-rich deposits have high potential for preserving biosignatures. But in my opinion, at this distance, these outcrops look to still be predominantly the sandy delta front, even though they're near the base of the delta scarp. Perseverance is not going to be approaching these outcrops though, so I guess that's not super relevant. Hopefully, at the base of the 'three forks' area, Perseverance will encounter the muddy prodelta deposit that the astrobiologists are so eager to drill.