Kari-Kari (caldera)

After emplacement of the caldera, intrusive activity generated the Kari-Kari dome which was originally considered to be a batholith.

[3] With an age of 21,000,000 years it is the oldest caldera structure that has been identified with unaided satellite imagery.

[4] It is part of the ignimbrite province of the Miocene Central Andes, which includes also the Altiplano-Puna volcanic complex with an estimated volume of 11,000–13,000 cubic kilometres (2,600–3,100 cu mi).

[10] The Kari-Kari dome was originally assumed to be a batholith; later it is being interpreted as a resurgent ignimbrite structure.

[13] The formation of Kari-Kari may have been influenced by deep seated faults which form lineaments visible at the surface.

[3] The Cordillera Andacaba area in the southern caldera is the site of several mining districts, which include lead-zinc or tin rich areals.

[15] The Kumurana mine is located in the southern part of the caldera,[16] its mineralization occurred at temperatures of 213–413 °C (415–775 °F).

[17] The Cerro Rico stock has been extensively hydrothermally modified and a number of minerals are found there.

[21] Overall, the Kari-Kari rocks are peraluminous and originated from the amphibolite-granulite segment of the crust under the influence of magmatic underplating.

These rocks were subsequently subject to hydrothermal alteration by boron- and chlorine-rich fluids which in multiple stages formed the mineral veins.

[3] Activity in the Kari-Kari and neighbouring Los Frailes ignimbrite plateau spans 17,000,000 – 2,000,000 years ago.

[13] These crystal rich welded tuffs accumulated within the caldera and have a volume of about 500 cubic kilometres (120 cu mi).

[22] The Agua Dulce volcanics are of similar ages as the Kari-Kari dome,[1] as is the Canteria ignimbrite.

[11] A weighed age estimate for the Agua Dulce, Kari-Kari, Kumurana and Canteria formations is 21,400,000 ± 400,000 years ago.