Hi !!
OK Gaetan.
Landsat 742RGB
Image of Brandberg and Messum Crater, North Ugab River. North Namibia, 350 km north Swakopmund.
https://2img.net/r/ihimizer/img524/986/aaamessumcratbrandbergstruct1y.jpghttps://2img.net/r/ihimizer/img524/986/aaamessumcratbrandbergstruct1y.jpghttps://2img.net/r/ihimizer/img524/986/aaamessumcratbrandbergstruct1y.jpgThis is the Brandberg Massif in Northern Namibia, the dominant geographic feature of the central Namib desert.
Both features are early Cretaceous granite ring complexes which intrude deformed Pan African Chain (~500Ma) age metamorphic rocks of the Damara Orogeny
Massif is an exhumed granite intrusion dating to some 120 million years ago. It rises to 2,606 meters over the eroded plain and is higher than any other feature for hundreds of kilometers.
This dome covers an area of 650 square kilmeters above the surrounding desert.
It is an important habitat for high-altitude savannah species, and is of great archeological interest for the many prehistoric cave paintings found among its granite cliffs.
see Brandberg White Woman.
Slightly south and to the west of the Brandberg is the much-eroded Messum Intrusion.
Both of these intrusions reflect a period of extraordinarily widespread geological unrest in the Earth's history, which preceded the opening of the Atlantic Ocean and the effusion of vast volumes of basaltic lavas of the Karoo formation that form the Drakensberg plateau.
Karoo lavas are exposed immediately to the west of the intrusion.
Rocks forced aside by the upward movement of the intrusion are visible encircling the margin of the Brandberg, tilted sharply upward. Ancient gneisses, distinguished by their lineated texture, are conspicuous along the dry river valley in the center of the frame.
The existence of a set of lavas in South America of the same age and type as those of the Karoo was used for many years by some geologists as strong evidence that Africa and South America had once been united.
However, their arguments were not widely accepted until geophysical data demonstrated the reality of plate tectonics.
My interest for this structure is to compare with Guelb er Richât in West Africa and Appalaches Formations in N. America at Triassic period (before aperture Atlantic Ocean).
DRAG.