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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 Minerals are the fundamental constituents of Earth, and mineral names appear in scientific literature for disciplines including geology, chemistry, materials science, biology, and medicine, among others. Choosing a name is the full responsibility of the authors of new mineral proposals submitted to the International Mineralogical Association (IMA). Scientific nomenclature and its traditions have evolved over time, and consequently, mineral names track changes in the landscape of mineralogy with respect to language, technology, and culture. To evaluate these changes, the namesake information for all 5896 minerals approved by the IMA or “grandfathered” into use as of December 2022 was recorded and categorized within a workable database. The compiled information yields diverse insights into the intersection of science and culture and could also be used to project future trends. In this study, we used the name database to investigate gender diversity among mineral eponyms. More than half (ca. 54%) of all mineral species are named after people, the identities of whom are largely a reflection of the people that have historically been involved, in one way or another, in the geosciences and the mining industry. Of the 2738 people with minerals named for them, ∼6.1% are (interpreted to be) women. Nearly all minerals named for women were named during the last 60 years, although the growth rate in the year-on-year percentage of women among new mineral namesakes has slowed since about 1985. If current and historical trends hold, our model predicts that women will not comprise more than about 10.35% of newly established mineral namesakes in future years. The representation of women among mineral namesakes also differs starkly among countries. For example, Russians comprise 43.11% of women with minerals named for them but account for only 15.12% of all eponyms. However, there are additional disparities beyond the proportions of namesakes. For scientists who were alive when a mineral was named for them, women averaged 3.74 years older than men when evaluated over the same timespan (1954–2022). These results demonstrate that gender-based disparities are imprinted into current mineral nomenclature and indicate that gender parity among new mineral namesakes is impossible without unprecedented changes in the upstream demographics that are most likely to affect naming trends. 

Ti-isotope fractionation on the most Ti-rich minerals on Earth has not been reported. Therefore, we present a chemical preparation and separation technique for Ti-rich minerals for mineralogic, petrologic, and economic geologic studies. A two-stage ion-exchange column procedure modified from the previous literature is used in the current study to separate Ti from Fe-rich samples, while α-TiO2 does not require chemical separation. Purified solutions in conjunction with solution standards were measured on two different instruments with dry plasma and medium-resolution mode providing mass-dependent results with the lowest errors. 49/47TiOL-Ti for the solution and solids analyzed here demonstrate a range of >5‰ far greater than the whole procedural 1 error of 0.10‰ for a synthetic compound and 0.07‰ for the mineral magnetite; thus, the procedure produces results is resolvable within the current range of measured Ti-isotope fractionation in these minerals.