Planetary geology and the Puna
Planetary geology, alternatively known as astrogeology or exogeology, is a planetary science discipline concerned with the geology of the celestial bodies such as the planets and their moons, asteroids, comets, and meteorites. Although the geo- prefix typically indicates topics of or relating to the Earth, planetary geology is named as such for historical and convenience reasons; applying geological science to other planetary bodies. Due to the types of investigations involved, it is also closely linked with Earth-based geology.
The NASA has been studying the surface of the earth for some time now to try to find a place with similar conditions to those of Mars. For several years the attention fell on the arid Atacama Desert region, where the extreme conditions of drought have resulted in the formation of exotic salts and the total absence of organic matter.
Some professionals (R. Alonso / F. Anguita) have proposed to explore the deserts of the Puna in Argentina and particularly in the Puna of Salta, trying to find even more extreme conditions. The Puna Salteña is characterized by even more tension of physical and chemical elements.
The precipitation is almost absent, evaporation and winds reach extreme values, the thermal differences are the largest in the world (up to 61°C) and winter temperatures have sometimes reached -30°C.
Because of these conditions the rocks explode due to both, temperature differences and internal expansion of salts and water/ice, causing, as a result, a desert of sedimentary rocks. The sand and salt accumulate in the depression of the Puna so vegetation is inexistant in these areas.
Some salt flats are in a stage of self destruction because of lack of rain they are unable to regenerate themselves. Thus satellite images of the Puna can show some geological formations similar to those visible in the topography of Mars.
In summary the area of the Puna in Argentina, in Tolar Grande, should be considered an excellent laboratory for planetary geology. Travel in the remote Puna of Salta represents almost an extra-planetary travel experience. This is the most frequent comment from our travelers: ... I feel we are on another planet! ....
Source: La Puna Argentina, Ricardo N. Alonso