Preprints
Filtering by Subject: Geochemistry
Erosion-driven changes in soil cation exchange capacity quantified using barium isotopes
Published: 2026-04-22
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geomorphology, Physical Sciences and Mathematics, Soil Science
Human activities have perturbed the balance between rates of soil erosion and formation, driving declines in soil quality. However, quantifying these soil imbalances remains challenging, especially at large scales. Here we present a novel isotope mass balance approach that can be used to quantify river catchment wide rates of change in cation exchange capacity (CEC), a key soil quality metric, in [...]
Buffered Byproduct Regime Shift: Deceptive Stability, Buffer Slack, and Regime Reorganization in Earth-System Transitions
Published: 2026-04-20
Subjects: Biogeochemistry, Climate, Earth Sciences, Geochemistry, Other Environmental Sciences
Earth history includes episodes in which biological or geophysical processes generate persistent byproduct loads whose early effects are partially masked by environmental sinks and buffering pathways. This paper synthesizes established literatures on Earth-system revolutions, redox transitions, mass extinctions, and Anthropocene change into an explicit phase grammar termed Buffered Byproduct [...]
Terrestrial formation of calcium sulfate and carbonate assemblages in Atacama CO chondrites: Implications for Martian evaporitic environments
Published: 2026-04-15
Subjects: Cosmochemistry, Earth Sciences, Geochemistry, Planetary Geochemistry, Planetary Geology, Planetary Mineral Physics, Planetary Sciences
Evaporites are frequently reported in carbonaceous chondrites from hot and cold deserts, yet their origin remains debated between formation on the parent body or by post-fall terrestrial alteration. Here, we present a systematic characterization of Ca sulfate and Ca carbonate assemblages in four CO carbonaceous chondrites from different dense collection areas of the Atacama Desert (Los Vientos [...]
Agent-based Modelling of Microbialite Formation through Sedimentation and Precipitation Dynamics
Published: 2026-04-13
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Other Earth Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Fossil microbialites resulting from the interplay of sedimentation and microbially induced precipitation are among the oldest evidence of life on Earth and help geobiologists interpret many sedimentary environments. However, the factors governing their internal structure and external morphology are still poorly understood. Additionally, abiotic processes can mimic the morphology of some [...]
Platinum-Group Element systematics in the North Atlantic Igneous Province: new insights from Northern Irish and Irish magmatism
Published: 2026-04-01
Subjects: Geochemistry, Geology, Other Earth Sciences, Volcanology
The North Atlantic Igneous Province (NAIP) is one of the most prospective regions for Ni-Cu-Platinum-Group Element (PGE) mineralisation in Europe, and recent studies have discovered elevated PGE concentrations within its early lavas and minor intrusions comprising the British and Irish Palaeogene Igneous Province (BIPIP). This study presents an extended digital map of the regional mafic dyke [...]
Nickel Isotope Systematics in the Talvivaara Paleoproterozoic Black Shale Deposit Reveal Mineralogy-Controlled Fractionation with a Preserved Biogenic Signal
Published: 2026-04-01
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Nickel isotope systematics in sediment-hosted sulfide deposits are now more commonly used to infer redox and diagenetic processes, yet their potential to record biological signals and their preservation through diagenesis and metamorphism remains poorly constrained. Here we present micro-scale coupled δ60Ni, δ34S, δ13C, REE pattern, and paleoproductivity proxy data from the Paleoproterozoic [...]
mineralML: Leveraging Machine Learning for Probabilistic Mineral Classification
Published: 2026-03-27
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Probability, Statistical Methodology, Statistics and Probability, Volcanology
Characterizing phase assemblages in igneous rocks and the chemical variability within these phases is the fundamental basis of many petrological investigations. We present mineralML (mineral classification using Machine Learning), an open-source Python package that classifies common igneous minerals based on oxide chemical data, with prediction scores. mineralML employs a two-stage neural [...]
Transient liquid- and solid-dominated inflation of an upper crustal magma chamber: insights from the Carlingford Complex (Ireland)
Published: 2026-03-18
Subjects: Earth Sciences, Geochemistry, Geology, Volcanology
Layered intrusions are the crystallised remnants of magma reservoirs and preserve a detailed record of magma storage, differentiation, and recharge processes in the upper crust. Their assembly is commonly categorised into two end-member emplacement regimes: long-lived liquid-dominated magma chambers, and incrementally assembled crystal-rich mush systems. These end-members are often presented as [...]
From "Ion-Adsorption" to "Ion-Adsorbed" Rare Earths: Terminological Drift, AI Paraphrasing, and the Erosion of Geochemical Precision
Published: 2026-03-17
Subjects: Earth Sciences, Geochemistry
The rapid adoption of artificial intelligence (AI) tools for writing and paraphrasing is transforming scientific communication. While such tools can improve linguistic fluency, their misuse, particularly when employed to mechanically rephrase text, may introduce subtle but consequential distortions in scientific terminology. In disciplines such as geochemistry, where terminology is closely tied [...]
Trace element contamination of sand samples by grinding
Published: 2026-03-11
Subjects: Earth Sciences, Environmental Sciences, Geochemistry
Blanks during powdering processes were examined for major and trace elements using inductively coupled plasma mass spectrometry (ICP-MS). Quartz sand (reference CV32.2) was used as a test substrate for powdering with grinding mills of several kinds: an agate mortar grinder, a stainless steel mortar grinder, a hard porcelain mortar grinder, an agate hand mill, and a hard porcelain hand mill. The [...]
Stable isotopic composition, paleoecology, and habitat of the ammonite Sphenodiscus lobatus in the Late Cretaceous (Maastrichtian) Western Interior Seaway
Published: 2026-03-03
Subjects: Earth Sciences, Geochemistry, Paleobiology, Paleontology, Sedimentology
Despite their abundance as fossils, the life histories of ammonites are still poorly understood. We analyzed the oxygen (δ18O) and carbon (δ13C) isotopic composition of well-preserved shell material taken from different growth stages of the streamlined oxyconic ammonite species Sphenodiscus lobatus from the Upper Cretaceous (Maastrichtian) Pierre Shale and Fox Hills Formation of South Dakota. [...]
Biotite/melt trace-element, lithium, and F-OH partitioning in silicate magmas
Published: 2026-02-17
Subjects: Earth Sciences, Geochemistry, Inorganic Chemistry, Materials Chemistry, Other Earth Sciences
Biotite is a key hydrous silicate mineral in evolved magmatic systems, but its control on the behaviour of minor- and trace-elements, in particular Li, Nb, F and the REE is not well understood. Here, we quantify that control in sodic (per)alkaline H2O-saturated magmas with variable F-content through crystallisation experiments at 650–800◦C and 200 MPa total pressure, at log f O2 ≈ FMQ +1. [...]
Mid-crustal Origin of Alkaline Magmas in the Arosa Zone: Evidence from Primary Analcime and Xenolith Interaction at the Rothplattenbach Complex (Germany)
Published: 2026-02-13
Subjects: Geochemistry, Geology, Mineral Physics, Physical Sciences and Mathematics, Volcanology
The petrogenetic evolution of the alkaline magmatic rocks of the Rothplattenbach Complex was investigated by X-ray diffraction phase analysis and crystallographic lattice-parameter determination. The study focuses on the identification of primary analcime occurring in paragenesis with Ca-rich plagioclase (An₇₇) and diopsidic clinopyroxene. Phase-equilibrium modelling indicates that magma [...]
Multiple-Well Monitoring Site Adjacent to the Midway- Sunset and Buena Vista Oil Fields, Kern County, California
Published: 2026-02-12
Subjects: Earth Sciences, Geochemistry, Geology, Hydrology, Physical Sciences and Mathematics
Groundwater quality in and around oil fields in the Southern San Joaquin Valley is of interest to many California residents that rely heavily on groundwater for domestic, commercial, and agricultural use. To help assess the effects of historical oil-field activities and natural geologic sources on groundwater near the southwest margins of the Kern County Groundwater Subbasin, a multiple-well [...]
Magmatic volatile budgets of the 2014 Tavurvur eruption at Rabaul Caldera, Papua New Guinea
Published: 2026-01-30
Subjects: Earth Sciences, Geochemistry, Volcanology
Rabaul is a caldera volcano on New Britain Island, Papua New Guinea, whose active cone Tavurvur ranks seventh globally for long-term SO2 and CO2 emissions. It is unknown why Rabaul is such a strong emitter of volcanic gases. Magma mixing between basaltic and dacitic magmas is envisioned to play a fundamental role in driving eruptions at Rabaul, but the compositions of mafic recharge magmas and [...]