Tectosedimentary analysis of Cauchari evaporite Basin, Province of Jujuy, Argentina.

C.I GALLI; R. ALONSO; ORNELA ESTEFANÍA CONSTANTINI; M. MUTTI

Selva Di Val Gardena

Conferencia; Dolomieu Conference on Carbonate Platforms and Dolomite; 2016

IntroductionThe Cauchari basin is located in the Department of Susques, Jujuy province, in the Puna Plateau of Northwest Argentina (Figure 1). This region, together with Bolivian Plateau, concentrates many evaporitic deposits with a high economic potential, accumulated during the Neogene-Quaternary period. The most important lithium and borate deposits in South America are concentrated in the Central Andes.Approximately 15 Ma ago began the development of intermontane basins governed by extreme aridity conditions, the accumulation evaporates and a functional internal drainage in Puna basins as a result of subsidence occurred in the Miocene [1] [2].The Puna constitutes an ?evaporitic province? with salars until deep levels and where in addition to having evapofacies of cast and halite have borates. Deposition of borates began at about 8 Ma ago and it is believed to be related to volcanic activity in centripetal drainage basins [3] [4].Cauchari basin is characterized by continental deposits upper Cenozoic rocks. The largest lithium and borate accumulations are part of the Late Miocene, composed by different evaporitic and clastic units. On the western edge of the Cauchari salar its found the most extensive travertine platform in the Puna that retain features of ancient hot springs. This platform is associated with the fault which lifts up the Palaeozoic block. At the southern there are borates deposits of ulexite [1] [4] [5]. On the eastern edge of the Cauchari salar extends a strip of red Neogene layers. There are cast and lacustrine carbonates in widespread. On the northeast edge of Cauchari salar, at the Cerro Negro, basaltic flows cover the red layers with interbeded of green lacustrine layers, where besides cast and travertine it was also found halite. [6] The objectives is analyse the evolution of Cauchari basin during the Andean tectonics, and obtain a characterization of clastic and evaporitic process, sedimentary facies of the saline system, stratigraphic control, structural and sedimentary controls of surface and underground outcrops with the purpose of establish the tectonic control, lithium and boron distribution in the salar and the possible source areas. Establish the ion contribution which is generated by leaching of the lithology in the basin and establish the process and lithological paternal relation of lithium, boron and other elements of the brines. The proposal is to generate an evolution basin model, and in the future correlations with neighbouring areas.