Preprints
Filtering by Subject: Geology
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 [...]
The critical role of stored energy in metamorphism
Published: 2026-10-09
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
The mechanical behaviour of the Earth is widely assumed to change with increasing timescale as rocks progressively relax imposed stresses [1]. On short timescales, elasticity dominates and its release drives earthquakes [2]; at intermediate timescales, viscoelastic relaxation facilitates processes such as glacial rebound [3]; whereas over geological timescales viscous deformation dominates, [...]
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 [...]
Understanding Earthquake Physics with On-Fault Observatories
Published: 2026-10-02
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquakes often strike without warning. Current fault monitoring infrastructure is not sensitive enough to detect signals such as accelerating fault creep or dilation, which laboratory experiments and numerical models predict may precede large earthquakes. Here we argue that a paradigm shift is needed and technically achievable: from inferring faulting processes from a distance with surface [...]
Leveraging Ocean Data and Models: Building the Data Infrastructure, Workforce, and Modeling Capacity to Synthesize Earth’s Ocean Observations
Published: 2026-09-25
Subjects: Artificial Intelligence and Robotics, Atmospheric Sciences, Biogeochemistry, Climate, Computer Sciences, Databases and Information Systems, Earth Sciences, Environmental Sciences, Fresh Water Studies, Geology, Hydrology, Meteorology, Numerical Analysis and Scientific Computing, Oceanography, Other Earth Sciences, Other Oceanography and Atmospheric Sciences and Meteorology
NASA’s aquatic and marine research enterprise within the overarching NASA Biosphere Program is entering an era of unprecedented data abundance. MODIS and the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission already generate ocean color data at rates that strain legacy processing and archiving workflows, and forthcoming missions will add further volume and complexity. These satellite [...]
Deep seismo-volcanic tremors constrain the magma supply from the mantle
Published: 2026-09-24
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Volcanic eruptions are driven by magma supplied from the mantle, yet deep magmatic flux remains poorly constrained. Here we propose to quantify it based on deep seismic tremors. We adopt a model of tremor generation by rapid growth of gas bubbles in response to magma decompression and establish a physical relationship between the cumulative seismic moment and the volume of the ascending magma. By [...]
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 [...]
Was the Pre-Event SWIR Anomaly at Tsangbu Ri a Genuine Glacier-Collapse Precursor? A Calibrated Multi-Glacier Test of the 2026 Case
Published: 2026-09-19
Subjects: Applied Statistics, Geographic Information Sciences, Geology, Geomorphology, Glaciology, Hydrology, Planetary Geology, Planetary Glaciology, Remote Sensing, Spatial Science, Tectonics and Structure
On 26 August 2026 a compound bedrock-and-glacier failure on the northern flank of the Langtang Lirung–Tsangbu Ri (Kimshung) massif, Nepal–China border, generated a rock–ice avalanche and a catastrophic downstream flood along the Bhotekoshi–Trishuli river system. A pre-event Sentinel-2 shortwave-infrared (SWIR2–NIR–Red) composite (12 August 2026) shows a sharply bounded, strongly saturated [...]
Biomarkers Thermal Maturity Parameters in Bitumen as a Proxy for Seismic vs. Aseismic Mirror-like Fault Surfaces
Published: 2026-09-18
Subjects: Geology
Mirror-like Surfaces (MSs) are ultra-polished fault surfaces that experimental studies have shown can form during seismic and aseismic deformation (slip rates ≈1 m/s vs. <0.0001 m/s). To determine which MSs form during seismic (rapid temperature increase) or aseismic (negligible temperature increase) slip along the fault, we measured sterane and hopane thermal maturity parameters in bituminous [...]
New insights into rift evolution from data-constrained burial and thermal histories at the northern South China Sea margin
Published: 2026-09-18
Subjects: Earth Sciences, Geology
The evolution of the rifted margin of the northern South China Sea challenges predictions of previous models but a knowledge gap still exists regarding how thermal history varies at different locations and times of rifting. International Ocean Discovery Program (IODP) Expeditions 367/368/368X collected samples of sediment that can be used to model the thermal evolution at different rifting stages [...]
Global isotopic proxy records for Ordovician temperature reconstruction
Published: 2026-09-16
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The Ordovician represents a critical interval in the Phanerozoic, marked by two profound biological events: the Great Ordovician Biodiversification Event (GOBE), with an unprecedented tenfold increase in marine species diversity, which was abruptly terminated by the Late Ordovician Mass Extinction (LOME), one of the most severe extinction events in Earth's history, wiping out approximately 85% of [...]
The depths and thicknesses of the magma bodies that fed some of the largest Quaternary eruptions on Earth
Published: 2026-09-14
Subjects: Geology, Volcanology
Volcanic systems are critical for the evolution and dynamics of the Earth; yet, our understanding of the plumbing systems that feed eruptions is hampered by our inability to directly observe magmas at depth. We present a compilation of matrix-glass data and rhyolite-MELTS pre-eruptive storage pressures for eleven Quaternary VEI 6+ caldera-forming eruptions worldwide with volumes ranging from 35 [...]