Preprints
Filtering by Subject: Geochemistry
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 [...]
A New Paradigm for High-Level Radioactive Waste Disposal: Intrinsic Radionuclide Properties and Comparative Hazard
Published: 2026-01-21
Subjects: Environmental Engineering, Environmental Sciences, Geochemistry, Geology
This paper develops a hazard- and pathway-based framework for high-level radioactive waste (HLW) disposal grounded in intrinsic radionuclide decay characteristics, geochemical behavior, and comparative hazard. We examine the physical and geochemical properties of key radionuclides and quantify lifetime cancer risk from chronic ingestion on a per-unit-mass basis using established regulatory [...]
Magmatic degassing as the primary source of salt in Archean oceans
Published: 2026-01-21
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
The salinification of Earth’s early oceans impacted both the climate and the evolution of life. However, available halogen data of Archean seawater samples are at apparent odds with a conventionally assumed mantle origin of sea salt, highlighting a critical lack of mechanistic understanding of how the Archean oceans became salty. Here, we present new triple halogen (Cl-Br-I) data from high [...]
Petrological insights into magma storage and evolution at Rabaul Caldera, Papua New Guinea
Published: 2026-01-21
Subjects: Earth Sciences, Geochemistry, Volcanology
Rabaul is a caldera volcano in Papua New Guinea. Its most recent caldera-forming eruption occurred ~1400 years ago, with numerous intra-caldera eruptions since. Erupted whole rock compositions are commonly attributed to fractional crystallisation along a single liquid line of descent, but mafic mineral clots indicate mafic recharge and magma mixing also influence whole rock compositions. [...]
The magnitude of equilibrium isotope fractionation of Mg between forsterite, diopside and melt at liquidus temperatures
Published: 2026-01-11
Subjects: Earth Sciences, Geochemistry, Mineral Physics
We examine the equilibrium fractionation of Mg isotopes between forsterite, diopside, and a coexisting melt at liquidus temperatures using a combination of analyses of petrological-experiment products and atomic-scale simulations. Our experiment yields ∆²⁶Mgol/melt = -0.058 ± 0.032 ‰ (2s.e.) and ∆²⁶Mgcpx/melt = 0.060 ± 0.034 ‰ (2s.e.) for crystals grown from a near-cotectic basaltic melt in the [...]
Reviewing chronostratigraphic uncertainty of the Ediacaran-Cambrian transition
Published: 2026-01-01
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Stratigraphy
The Ediacaran-Cambrian transition archives the widespread disappearance of ‘Ediacaran-type’ soft-bodied biota and the appearance of most modern animal body plans, including a major diversification of skeletal animals and styles of animal-substrate interaction. Despite over a century of study, our ability to confidently reconstruct the series of macroevolutionary events that inform origination and [...]
Solubility and speciation of sulfur in silicate melts under crustal conditions
Published: 2025-12-12
Subjects: Earth Sciences, Geochemistry, Geology, Volcanology
We have determined the solubility of sulfur as either sulfide (S2-) or sulfate (S6+) in a wide range of silicate melts at 1 atm pressure and temperatures of 1050° to 1250°C. The method involved suspension of the melt in either a mixture of CO2-CO-SO2 (sulfide solubility) or SO2 and air (sulfate solubility) for periods of up to 120 hours. Sulfur concentrations, measured by electron microprobe were [...]
Recurrent evacuation of mantle mush by mafic recharge in ocean island basalts, recorded by La Palma clinopyroxene
Published: 2025-12-03
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Volcanology
Temporal variations in magma plumbing architecture and magmatic processes influence eruption priming and the interpretation of pre- and syn-eruptive signals. Yet, how these processes operate in low-flux volcanoes remains poorly constrained, leaving a key gap in understanding eruption precursors. Here we examine the temporal evolution of magmatic processes at La Palma, Canary Islands, a low-flux [...]