Preprints
Filtering by Subject: Geochemistry
Reassessing long-term exhumation rates in magmatic terranes
Published: 2026-05-10
Subjects: Earth Sciences, Geochemistry, Geology, Tectonics and Structure
Crustal exhumation is central to mountain building, weathering, and sediment production processes, which significantly influence the composition and behavior of Earth’s oceans and atmosphere. It also controls the formation, enrichment, and preservation of porphyry copper deposits, which are a vital source of metals for the clean energy technologies underpinning the global green energy transition. [...]
Polar ice-cores unravel the formation of a UV window during magnetic field collapse ~ 42 ka BP
Published: 2026-05-08
Subjects: Earth Sciences, Environmental Sciences, Geochemistry, Other Environmental Sciences, Physical Sciences and Mathematics
During geomagnetic excursions (GEs), compromised magnetic field and increased cosmic-ray bombardment can deplete the ozone layer forming ‘UV window(s)’ in the Earth’s atmosphere. Here, using triple sulfur-isotope systematics in polar ice-core sulfate record spanning 600 years of the Laschamp GE, we provide direct evidence of the formation of a UV window. Several events of UV-induced anomalous [...]
A comprehensive study of the CO2-O2 isotope exchange technique to standardize triple oxygen measurements in CO2
Published: 2026-05-05
Subjects: Earth Sciences, Geochemistry
Reevaluating the Abbabis Complex: Intrusive relationships and melt connectivity in a syn-orogenic migmatite–granite system, Damara Orogen, Namibia
Published: 2026-04-25
Subjects: Earth Sciences, Geochemistry, Geology, Stratigraphy, Tectonics and Structure
The Abbabis Complex in the Damara Orogen has long been interpreted as a pre-Damaran (c. 1–2 Ga) basement terrane unconformably overlain by Neoproterozoic metasedimentary rocks of the Damara Supergroup. New field mapping and geochemical data from the Ida Dome and Husabberg Anticlinorium encourages re-evaluation of this interpretation. The Abbabis Complex comprises migmatites, larger leucogranite [...]
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 [...]
Before the Threshold: Deceptive Stability, Buffer Slack, and Earth System Transitions
Published: 2026-04-21
Subjects: Biogeochemistry, Climate, Earth Sciences, Geochemistry, Other Environmental Sciences
Earth history includes episodes in which persistent biological or geophysical byproduct loads are absorbed by finite environmental sinks and buffers, preserving apparent stability while the capacity to absorb further stress declines. This paper synthesizes literatures on Earth system revolutions, redox transitions, mass extinctions, and Anthropocene change into a comparative framework termed [...]
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: 2026-03-04
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. [...]