Preprints
Filtering by Subject: Geochemistry
From rifting to collision: deep closure of a Wilson cycle during the Archean–Paleoproterozoic transition at the Carajás-Bacajá boundary, Amazonian Craton
Published: 2026-10-21
Subjects: Earth Sciences, Geochemistry, Geology, Tectonics and Structure
The Carajás-Bacajá boundary preserves complementary archives of continental rifting, passive-margin development, subduction, collision and post-collisional exhumation across the Archean-Paleoproterozoic transition. We present whole-rock lithogeochemistry, Sm-Nd isotopes, U-Pb zircon geochronology and thermobarometry from the Vila Santa Fé-Rio Preto association, a mafic-felsic granulitic [...]
Decoupling ore formation, ductile fabric and hydrothermal upgrading in the giant Salobo IOCG deposit, Carajás Province, Brazil
Published: 2026-10-21
Subjects: Earth Sciences, Geochemistry, Geology, Tectonics and Structure
The Salobo deposit is the largest Cu-Au deposit of the Carajás Mineral Province, northern Brazil, and is hosted by altered volcanosedimentary schists of the Itacaiúnas Supergroup along the Cinzento Lineament. Multiscale structural analysis, mineral chemistry and published geochronology define four structural families: Pre-Dn, Dn, Dn+1 and Dn+2. The Pre-Dn event comprises high-temperature K, K-Fe [...]
Mantle, lithospheric and crustal controls on large igneous province magmatism: petrogenesis of the Antrim Lava Group, North Atlantic Igneous Province
Published: 2026-10-21
Subjects: Earth Sciences, Geochemistry, Volcanology
Continental large igneous province (LIP) volcanism is the result of long-lived interactions between mantle plumes, lithospheric topography, ascending melts, and crustal lithologies. Disentangling the competing effects of such factors is required to understand the petrogenesis of LIP magmas and ultimately the controls on their geochemical and isotopic diversity and on ore-forming processes. The [...]
MCR-GeoChem: Aharmonized, quality-flagged open compilation of whole-rock and mineral geochemistry for the 1.1 Ga Midcontinent Rift in Michigan, Minnesota, and Wisconsin
Published: 2026-10-21
Subjects: Earth Sciences, Education, Environmental Sciences, Geochemistry, Geology, Higher Education, Physical Sciences and Mathematics
Nickel, copper, cobalt, and the platinum-group metals are all on the final 2025 U.S. List of Critical Minerals, and the 1.1-billion-year-old Midcontinent Rift around Lake Superior hosts some of the largest domestic resources of them. The rock chemistry needed to study these systems is public but fragmented: it is spread across the U.S. Geological Survey (USGS) National Geochemical Database, [...]
Earth's Bad Decades: A Sedimentary Record of the Chicxulub Aftermath from the New Jersey Coastal Plain and Offshore
Published: 2026-10-16
Subjects: Earth Sciences, Geochemistry, Geology, Geophysics and Seismology, Sedimentology, Stratigraphy
The New Jersey Coastal Plain (NJCP) preserves records of the Chicxulub impact approximately 2,500 km from the crater, providing a unique archive of ejecta fallout, sediment reworking, ecological disruption, and recovery following the end-Cretaceous mass extinction. Preservation of impact deposits varies with depositional setting. Offshore sections beneath the NJ continental shelf and slope [...]
Lixa v0.1.2: an open-source, image-informed framework for closed-loop design of leaching processes for domestic critical-mineral recovery, from the pore to the plant scale
Published: 2026-10-14
Subjects: Earth Sciences, Engineering, Geochemistry, Hydrology, Mining Engineering, Physical Sciences and Mathematics
Leaching takes a metal out of a rock and into a solution. In the United States, rare earth elements, lithium and scandium occur mostly in rocks where the metal is thinly spread through a porous matrix: weathered clays, coal ash, lithium claystones and bauxite residue. For such rocks the leaching recipe (reagent, concentration, temperature, particle size, liquid-to-solid ratio and contact time) [...]
MELVIS: An open-source web application for computing and modelling the viscosity of volcanic melts
Published: 2026-10-13
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Volcanology
The viscosity of volcanic melts governs magma transport, eruption dynamics, and a broad range of magmatic processes, so predicting it as a function of temperature, composition, and dissolved water content is central to physical volcanology. Yet no freely accessible tool integrates global machine-learning predictions, physically motivated viscosity equations, and composition-specific models [...]
X-ray microdiffraction mapping on experimentally synthesized clinopyroxenes
Published: 2026-10-12
Subjects: Earth Sciences, Geochemistry, Geology, Volcanology
Crystallographic parameters serve as fundamental archives of crystallization environments, with pressure generally acting as a key variable governing crystal formation. In magmatic systems, tracking crystallographic and chemical parameters in clinopyroxene is critical for robust magmatic thermobarometry and reconstructing crystal life histories. While chemical thermobarometry is limited by melt [...]
Drilled petit-spot basalts reveal asthenospheric mantle heterogeneity before subduction
Published: 2026-10-09
Subjects: Geochemistry, Geology
Submarine petit-spot volcanoes form where oceanic plates bend and flex before sinking into subduction zones, providing a rare opportunity to sample mantle-derived melts before subduction. Here we report results from the first scientific drilling of a sediment-buried petit-spot volcano during International Ocean Drilling Programme Expedition 502, recovering basalts from a previously inaccessible [...]
When and why does CO2 mineralization in basalts stall? A critical review of microscale passivation, pore-clogging mechanisms and the multiscale imaging needed to resolve them
Published: 2026-10-08
Subjects: Geochemistry, Geology
In-situ CO2 mineralization in basalts is among the most secure forms of geological carbon storage. Field pilots report rapid mineralization and, where monitored, stable injectivity, yet many laboratory experiments show that carbonation slows or stops long before the reactive cation inventory of the rock is consumed. We synthesise four field pilots (CarbFix1, CarbFix2, Wallula, Jizan) and 37 [...]
Bulk iron-sulfur ratio (Fe/S) conditional proxy for sulfurized, TOC-rich sediments: insights and comparison of compositional model with real data utilizing the Pyrite-TOC-Fe-S compositional space
Published: 2026-10-04
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Bulk iron-sulfur (Fe/S) ratio can be a proxy for sulfurized organic matter in organic-rich shales, particularly those prone to be siliceous or carbonate. First part uses a theoretical model of a compositional system consisting solely of iron, sulfur, TOC, and pyrite to demonstrate how the Fe/S ratio can indicate the presence of sulfurized organic matter using the model’s assumption of sulfur [...]
Model-Based Assessment of Geogenic Radon Exposure in Chaco Canyon and Adjacent Ancestral Puebloan Residential Settings
Published: 2026-09-29
Subjects: Environmental Chemistry, Environmental Health and Protection, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Public Health, Geochemistry, Other Earth Sciences, Other Environmental Sciences, Other Physics, Paleontology, Sustainability
Naturally occurring radon-222 and its short-lived alpha-emitting progeny are important sources of environmental radioactivity in enclosed, earth-contact spaces, yet their potential relevance to archaeological built environments has rarely been quantified. Here we evaluate chronic radon exposure in Chaco Canyon, where Ancestral Pueblo people occupied earth-contact and semi-subterranean rooms [...]
P-T-t-d history of the Greater Himalayan Sequence in the Zanskar Shear Zone, NW India
Published: 2026-09-23
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Tectonics and Structure
We present a synthesis of pressure-temperature-time-deformation (P-T-t-d) conditions that track the evolution of the Greater Himalaya Sequence (GHS) exhumed along the Zanskar Shear Zone (ZSZ), the western arm of the South Tibetan Detachment and that spans the entirety of the Himalayan range. The dominant mineralogy is Qz + Kfs + Pl + Bt + Grt + Ilm + Sil(Fi) ± Ms ± Ky ± St. P-T paths constructed [...]
Hydrogeochemical Vectoring to Concealed Porphyry Copper Systems Using Unsupervised Machine Learning: A Case Study from Central British Columbia, Canada
Published: 2026-09-23
Subjects: Geochemistry, Geology, Numerical Analysis and Scientific Computing
Environments with thick cover present a challenge to surficial exploration efforts the Canadian Cordillera has extensive Quaternary glacial till and sediment cover, making it difficult to find hidden ore bodies. An alternative is using hydrogeochemistry as an exploration tool, to detect anomalies associated with mineralization. This study demonstrates the hydrogeochemical vectoring to [...]
Mineral-specific ligand and redox dynamics of adsorbed platinum: Pathway-dependent mobility during terrestrial weathering
Published: 2026-09-17
Subjects: Geochemistry
Weathering zones developed above ultramafic rocks, such as oxidized ores, soils, and laterites, concentrate the critical mineral platinum and represent a promising future resource. Prior work has documented Pt accumulation in these zones, including its common association with iron oxides. However, the fundamental mechanisms that control Pt retention versus mobilization during weathering are not [...]