Lmst

My folks are on an seniors' excursion in Catalunya; they just sent me this photo, I think from La Mussara, and I had to resist the urge to preach abt #IAmNotAGeologistTMBut 🙃

Long calcareous layered outcrops on a 200-300m cliff, lushly covered in trees. It's a fine-weather day and the skies are deep blue.

Mid-thread intermission!!!

Disclaimers:

- #IAmNotAGeologistTMBut
- these are preliminary summaries for a conference, peer-review unknown
- the press release headlines when LPSC starts will most likely tell a completely different story (hype? 😉)
- the thread is for my own reference, but it hopefully helps you too
- adding them in no specific order, I have a long backlog to go through yet

Still haven't even gotten to the session I'm most interested in, sediments & stratigraphy 😀

From #PlanetArtober2023: "Martian Delta" by yours truly

What must be rocks left behind by a subglacial stream in the local park #IAmNotAGeologistTMBut

Large grey-brownish rocks with joint sets standing on snow-covered sand

#kratrarsombergeffekten #IAmNotAGeologistTMBut #Mars

Source: https://planetarygeomorphology.wordpress.com/2023/09/01/meter-scale-ripples-on-mars-change-in-size-according-to-atmospheric-density/

Barchan dune covered by dark-toned ripples migrating over aeolian ridges. If you let your brain interpret the slip face as the shadow of a salient, you get a fun relief-inversion effect.

I found this old(ish) paper about #JezeroCrater and the delta really educative and accessible even when #IAmNotAGeologistTMBut

Schon et al. "An overfilled lacustrine system and progradational delta in Jezero crater, Mars: Implications for Noachian climate"
https://www.researchgate.net/publication/258688201_An_overfilled_lacustrine_system_and_progradational_delta_in_Jezero_crater_Mars_Implications_for_Noachian_climate

A lot of substance and recognizable features in almost every figure, some examples:

Fig 4. : Topographic profiles from MOLA point data of Jezero crater (top) and a similarly sized fresh crater (bottom) found in Elysium Planitia (8.25 1 N, 125.75 1 E). This comparison shows that Jezero crater (top) has experienced approximately 1-km of infilling compared to the morphologically fresh crater. Lake level is shown at À 2400 m as suggested by the elevation of the outlet.

Fig. 10: Escarpment of the deltaic deposits truncates a scroll bar. The orientation of this meander indicates that the direction of migration was proximal (toward the watershed, away from the escarpment). This orientation requires a more extensive delta in the past.

Fig. 12: Scroll bars. Numerous scroll bars (lateral accretion topography) are observed adjacent to Belva crater on the delta plain and stratigraphically below erosionally-resistant materials interpreted as channel sands. These features (A–H) result from the development of point bars at the inside of distributary channel meander bends. Arrows indicate the direction of channel migration. Unconformities in the scroll bar patterns are common and suggest successive channel migrations.

Fig. 14: Channel deposits. (A) Stratigraphically above the scroll bars and epsilon cross-bedding are elongate erosionally resistant materials interpreted as channel sands. Consistent with the interpretation of a more extensive delta in the past, these channel sands would have been deposits in distributary channels sourcing more distal depocenters, and are high-standing because they are more erosionally resistant than overbank deposits. (B) Channels sands are mapped in green, scroll bars in blue, and craters in purple.

Trying new ways to visualize the #JezeroCrater delta chronology suggested in this preliminary paper
https://www.hou.usra.edu/meetings/lpsc2023/pdf/2067.pdf

I've animated the classified deposits in their rough form and with the estimated timeline. #PerseveranceRover is currently traversing deposit 'k'.

#IAmNotAGeologistTMBut

@65dBnoise @tom30519 reminder of this preview paper

https://mastodon.social/@sharponlooker/110071741890574220

Imho, it's probably a combination of all sorts, but I wouldn't be surprised if we get told that impact debris would mostly have been buried by later events #IAmNotAGeologistTMBut

Figure 1 on the linked paper, delineated estimated deposition layers and a putative timescale for them

@65dBnoise bah, I saw thicker veins the other day on the beach 🙃 #IAmNotAGeologistTMBut

Close-up of rocks on a Mallorca beach, with what looks like thicker veins than those Martian rovers tend to survey. Quick & dirty color editing to resemble the OP treatment, tip of my shoe for scale

#IAmNotAGeologistTMBut 😉

Foreground rock formations on a Mallorcan beach, cloudless sky and deep blue Mediterranean with boats in the background

Been helping Mrs Wife's family with some online genealogy lately. The other day, part nostalgia part breaking away from perusing wicked Austro-Hungarian empire 1800s handwriting, I switched to street view "visits" to my ancestors' villages in Spain. While looking for a vantage point over #Aldealpozo, I happen to see some interesting rocks by the side of the road... #IAmNotAGeologistTMBut 😉

https://maps.app.goo.gl/PB3dFntQmBL1wCvR6

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Street View snapshot of a country road in Soria province. The upward-sloping road crosses run-of-the-mill spanish Meseta landscape, with some subdued rock formations in different tones.

#IAmNotAGeologistTMBut #Flysch #BizkaianFlysch #Sopela #UribeKosta

Arrigorri outcrop. Tilted flysch, K-T boundary on the left.

The viewing spot as seen from the beach, in heavy rain.

#IAmNotAGeologistTMBut 😀

#IAmNotAGeologistTMBut

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