First petrological results along the traverse (Sol 1 to 57):
Diamonds in the basalt-like boulders ?

   

My first Analysis

Some stones at the rover's landing area were zoomed in with the mast camera or shot at with a laser beam. The results published so far are modest.
There is talk of basaltic material But that is not certain.

Frst datasets from the Visible and InfraRed (VISIR) sensor and Raman spectrometer instruments of the of the SuperCam were now published. VISIR uses reflected sunlight to examine the mineral compositions of rocks and soils. The Raman spectrometer uses a green laser beam for its observations. The result: Clear peaks of
Mg-carbonate were found in the spectrogram from an outcropd basaltic pumice-like stone in the ground (Sol 12).

An exposed rock (
Sol-37) is particularly noticeable and is described as puzzling. It has a smooth surface on which numerous rounded depressions can be seen.
Upon closer inspection of the published photo, I notice that some of the depressions still have a brownish (not secondary) filling. Obviously these are the typical remains of
disintegrated olivine aggregates, which are already missing in most of the holes.
The special density of the "basalt" groundmass (no mineralization can be recognized) indicates a volcanic origin in which the lava cooled down very quickly.
The olivines were already present as phenocrysts in the lava.
Another special feature that has not yet been commented on are the streaks or nests with
bright inclusions (crystals) in the dense groundmass of the stone.
Such bright inclusions can also be seen in other photographed stones.

It is now clear that these bright crystals, which are frequent in other angular boulders, not occur in the pumice-like deposits in the bottom of the crater.
In any case, the free, mostly angular boulders do not belong to the crater floor and were part of the eroded delta. They come from outside the crater and were transported by the
moraine of a glacier. The latest photos suggest an internal columnar-like structure, at least in parts of the basalt.
It is becoming increasingly clear that the bright crystals only occur in the basalt and the sintered contact zone between basalt and crust. The crystals in small stones on the ground result from the disintegration of columnar-like parts in the basalt or from the contact zone to the crust.

Sol-12
Zoom with the SuperCam on a stone in the ground that is identified as basaltic (?). Clear peaks of Mg-carbonate were found in a spectrogram.

    

Sol-16

Zoom with the SuperCam on free stone with the supposed weathering crust:

  • It is probably "basaltic" too; the bright inclusions were not identified (diamonds?)

  • The "crust" on the stone could be sintered ash

 
       

Sol-28

Intense occurrence of the bright, reflective crystals in a sunken boulder.
If we study the spectrogram of Sol-12 again, we notice a peak that signals hydrogen-carbon.
It could mean that the bright, reflective inclusions are diamonds. On the outer surfaces of the crystals, which have free atoms, is docked the hydrogen.


          

Sol-30

It is now clear that the bright crystals also occur in small aggregats on the soil. But it is not yet clear whether it is pumice or comes from the crust of the boulders.

 


         

Sol-37

A mysterious holey "basalt" boulder (15 cm) from the eroded part of the delta. Again the bright inclusions in the stone.
The smooth surface of the stone is striking. No crystallization can be seen, which indicates a rapid cooling of the magma after a volcanic event.
The holes: Decomposed and blown out phenocrysts (olivine?)


 
   

Sol-41

Again a boulder with bright inclusions. So far, however, an interpretation by the specialists at NASA is missing.


      

Sol-47

A stone related to that of Sol-37 ?
 


      

Sol-48

An angular boulder, as occurs in heaps on soil elevations,
with a knobby crust, similar Sol-16.


     

Sol-50

Further details from boulders on sandy elevation.
 What is it
? Basalt with a ash crust ?


    

Sol-51

There is great interest in the bright, reflective crystals. This stone was examined more closely with the SuperCam.
Bright crystals can be seen on parts of the surface (contact zone between basalt and sintered crust ?


   

Sol-52

The interest is in the broken sides of the stones with the strange "shell-like marks".

 


   

Sol-53

Stones in the heap are further examined for details.

Small holes in the basalt are apparently related to the knobby crust (consisting of aggregates) which can peel off, but is connected with the basalt as sinter (ash ?).


   

Sol-54

A selection of other interesting details to solve the ongoing puzzle to the origin of the boulders.

Some fractures in basalt shows probably an internal  columnar-like structure (!). This also explains the friable decay of some parts of the basalt. That explains also the "shell-like marks" on broken basaltic boulders.

       


It is becoming increasingly clear that the bright crystals only occur in the basalt and the sintered contact zone between basalt and crust. The crystals in small debris on the ground result from the disintegration of columnar-like parts in the basalt or from the contact zone to the crust.
The light-colored pumice deposits in the ground are free of crystals.