"So instead of water, try highly concentrated sulfuric acid for your working fluid."

Yes, as in waters such as this one.

---

"Also try also a "sedimentary" boulder ejected by impact from depth, with a fracture occuring on landing - that's your cross fracture."

Yes, it's 'possible', but how do you explain the polygonal features on the surface?

---

"By the way, my guess is still that those "berries" are tectites from impacts, and not condensates like the nodules found on the floors of oceans.

ep"

---

The Martian 'tectites' seem small compared to the majority of those found on Earth. Not much variety either. The Martian berries could also be of volcanic origin or...

Interesting study:

[The sediment sequence at the playa centre shows that the most abrupt transition from aridity to very humid conditions at 1000 B.C., was followed by a very long lake stage. The lower lake stage sediments of this event contain glassy spherules (5-100 gm dia) with a very varying composition, from pure Fe-types to types with the same basic composition as those found in the K/T-transition (e.g. Koeberl and Sigurdsson, 1992). Other outstanding wet periods found in the Tunisian material are 900-1000 A.D. and 1600-1700 A.D. In southern Sweden, several raised bog deposits have been investigated for their peat ash composition. Raised bogs, which receive all nutrients from the atmosphere, is an ideal archive of atmospheric fallout, the rate of peat accumulation being rather constant and the peat being easily dated with 14 C. The investigation indicate strongly increased atmospheric circulation in rhythmically appearing periods with high peaks centred around e.g. c.2200 B.C., 1000 B.C., 400 B.C., 200 A.D., 1000 A.D. and 1600 A.D. Harmonic analysis points at a periodicity of 570 years or 1140 years. Like in the playa deposits glassy spherules were found, having the same basic composition as the Tunisian material. In conclusion, both playa and alluvial fan deposits in Tunisia, and peat in Sweden points at a very turbulent Holocene with several sudden and dramatic climate event;, with unknown origin and extent The cultural traces indicate periods of extremely cold and humid conditions. The spherules found could be of volcanic origin but they are not associated with any known major volcanism, and their heterogeneous composition points at other formation mechanisms e.g. cometary impacts in ocean shelf sediments.]

---

I'm just exploring all the options.