Seminar of Stéphanie Duchêne, Univ. Paul Sabatier, GET (Toulouse)

Atacama : mountains of copper
Seminar of Stéphanie Duchêne, 21 mars 2023


The largest open-pit copper mines are located in the Atacama Desert in Chile. This copper has been mined for over 10,000 years, and Chile is currently the world's largest producer of copper, which accounts for over 40% of its GDP. Copper deposits form in two main ways: copper can concentrate around magmas emplaced several kilometres deep in subduction zones, or it can re-concentrate in soils when these old, solidified magmas are brought to the surface by erosion and are subjected to the circulation of rainwater, which dissolves and re-precipitates the copper as new minerals. A significant proportion of Chile's copper resources correspond to this second type of deposit. Rainwater? How is this possible in the driest desert in the world? By combining copper mineral dating with mineralogical and geochemical characterisation methods, we are trying to reconstruct the joint evolution of landform formation, climate evolution and copper formation and to understand the interactions between these three processes that make the Atacama an exceptional geological region.