Search for: All records

Abstract Volcano-sedimentary lithium (Li) deposits are a potential source of battery-grade Li, although the important factors controlling Li enrichment in these systems remain unclear. At Thacker Pass in Nevada, high-grade mineralization overprinted intracaldera lacustrine claystone made of authigenic Li-rich smectite with bulk grades of ~3,000 ppm Li, converting it to illitic claystone with grades of ~6,000 ppm Li. Some attribute this enrichment to burial diagenesis, whereas others propose lacustrine Li enrichment through leaching and climate-driven evapoconcentration enhanced by postdepositional hydrothermal alteration. To better understand Li enrichment in volcano-sedimentary systems, claystones from throughout Thacker Pass were analyzed using powder X-ray diffraction (PXRD), electron microprobe (EPMA), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), and stable isotope (clay δ18O, δ17O, and δ2H and carbonate δ13C and δ18O) methods. Compositional data suggest that illitization is required to achieve clay Li grades above ~0.9 wt % in Mg silicate clays because of a charge-coupled substitution that requires filling interlayer vacancies with K. Clay chemical trends and computational modeling exercises also suggest that F may be important in the formation of Li-rich clays by lowering kinetic barriers to clay precursor growth and illitization. The results are incompatible with diagenetic smectite/illite formation but are consistent with a model wherein authigenic smectite was subjected to hydrothermal alteration in the presence of a K-, Li-, and F-rich fluid that permeated the stratigraphy through a network of normal faults associated with caldera resurgence. These results also enhance our understanding of Li clay formation in other volcano-sedimentary systems. 

Abstract The importance of lithium for emerging industrial, aerospace, defense, and most significantly, lithium-ion battery technologies, is leading to a rapid increase in the demand for this critical resource. Although current global production of lithium is confined to historically exploited lithium-bearing pegmatites and closed-basin saline brines, new occurrences of these and several nascent types of lithium deposits are under varying stages of active exploration, development, and construction. This includes lithium resources associated with volcano-sedimentary deposits, continental and geothermal brines, and rare element granites. This paper presents an overview of lithium uses, production trends, the different types of lithium deposits, and their sizes, grades, and global distribution, as well as introducing the 24 papers in these two Special Issues of Economic Geology that review these lithium mineral systems and deposits in detail. These contributions include reviews and overviews of major deposit types, regional assessments of lithium provinces, deposit-specific research, and exploration techniques for finding additional resources. It is our hope that the scientific compilation and new insights presented in these two Special Issues of Economic Geology spur innovative thought and research in lithium deposit genesis and exploration to support the sustainable extraction of this critical element.