| Title | Li-rich clays in Andean systems: the influence of geothermal activity in their genesis |
|---|---|
| Authors | Morata, D., Maza, S., Abad, I |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | Lithium is one of the most important resources in modern society and has been classified as an energy-critical element due to the increasing demand for Li-ion batteries. The present-day Li market is dominated by Australia (Li extraction from pegmatites) and Chile (Li extraction from brines). A third, non-conventional Li-rich source, the volcanic clay deposits and hydrothermally altered saline lacustrine clays from explosive pyroclastic deposits, where Li is mostly concentrated in hectorite and other clay minerals, is currently under intense worldwide research programs. The combination of the following main geological processes has been proposed to explain the formation of hectorite: (1) alteration of volcanic ash or glass; (2) deposit of authigenic phases from saline lacustrine pore waters; and/or (3) incorporation of lithium into existing smectite clay deposits. In the Northern Chilean Andes, Li-rich salts flats are frequent and Li-rich clays have been analysed. Moreover, in some paleosalars Miocene sedimentary sequences, Li-rich clays (hectorite) has been also identified. The origin of these Li-rich clay deposits is proposed to be controlled by a dominantly volcanic origin for Li (caldera and ignimbritic eruptions) coupled with hydrothermal activity related with high geothermal gradients. The high-Li content of active geothermal systems in northern Chile and the presence of Li-rich clays in some salars and paleosalars in the same geographical location aims to propose a genetic relation between Andean Li-rich clays and active (and fossil) geothermal activity. Acknowledgments: ANID-FONDECYT Project 1250080 funded this work. |