Preprints
Filtering by Subject: Tectonics and Structure
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 [...]
Characteristics and consequences of H2O undersaturation and low melt fertility in mountain belt interiors
Published: 2026-10-15
Subjects: Earth Sciences, Geology, Tectonics and Structure
Continental deformation and crustal magmatism in orogenic settings are fundamentally linked to fluid availability and melting processes. Critical rheological transitions occur at approximately 7% melt volume, whereby melt-film connectivity reduces rock strength by as much as c. 90%, and at 20%, marking an onset of solid-to-liquid behaviour. The Mesoproterozoic Grenville orogen in Canada provides [...]
Active hazardous slow faults drive drainage evolution in the Atacama Desert
Published: 2026-10-14
Subjects: Earth Sciences, Geology, Geomorphology, Hydrology, Tectonics and Structure
The Atacama Desert of the Central Andean forearc is the driest non-polar region on Earth, where extremely low erosion rates preserve geomorphic markers over Myr timescales. Between 19°S and 20°S, subtle Quaternary east-vergent reverse faults deform the west-sloping landscape and disrupt drainage development. This setting provides a unique opportunity to investigate fault evolution, uplift [...]
A scaling law for stagnant-lid convection with composite visco-elasto-plastic rheology: application to Europa's ice shell
Published: 2026-10-09
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Planetary Geology, Planetary Sciences, Tectonics and Structure
Scaling laws relating the Nusselt number (Nu) and the Rayleigh number (Ra) are the standard tool for translating numerical models of convection into predictions of surface heat flux and the thicknesses of the stagnant lid and the rheological sublayer. Existing scaling frameworks for icy moons normalise this relationship using a temperature-dependence parameter, γ, calibrated against viscous and [...]
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 [...]
MilAMin in the browser: a million unknowns a minute in TypeScript and WebAssembly
Published: 2026-09-22
Subjects: Geophysics and Seismology, Numerical Analysis and Scientific Computing, Tectonics and Structure
In 2008 MILAMIN showed that a finite element code written in native MATLAB, a language then held to be too slow for large problems, could set up, solve and post-process one million unknowns per minute on a desktop, provided every stage of the pipeline gets equal care. This note brings the same pipeline to the web browser: Triangle meshing, 7-node Crouzeix-Raviart elements, supernodal Cholesky [...]
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 [...]
Seasonal variation of earthquake source characteristics of the long-duration Palghar swarm, western India
Published: 2026-09-18
Subjects: Earth Sciences, Geophysics and Seismology, Tectonics and Structure
A swarm sequence initiated in November 2018 in the Palghar region near the western coast of India, and continued with high intensity for two years. About 8300 earthquakes were found with horizontal and depth uncertainties of ≤ 1.5 km after relocation. The earthquakes were distributed along two narrow N-S oriented clusters, separated by ~5 km. We performed time-domain regional waveform full moment [...]
Fabric memory during repeated reversal shear in clay-rich materials: An experimental study using SEM, SP-µCT, and AMS
Published: 2026-09-09
Subjects: Tectonics and Structure
Fine-grained shear zones occur in both tectonic faults and gravitational landslides, making their origin difficult to determine from individual microstructural features alone. A potentially useful distinction is provided by deformation history: tectonic faults commonly experience repeated earthquake cycles in which the sense and magnitude of deformation may change, whereas landslide slip zones [...]
The Current State of Research on Deformation, Strain, and Velocity across the Alpine-Himalayan Belt Using Transcontinental Sentinel-1 InSAR and GNSS
Published: 2026-08-31
Subjects: Geophysics and Seismology, Tectonics and Structure
Research on present-day deformation across the Alpine-Himalayan belt has crossed a methodological threshold. Regional Sentinel-1 studies in Anatolia, Iran, and Tibet have now been joined by the first transcontinental three-dimensional velocity and horizontal strain-rate field, derived from more than 222,000 radar images acquired during 2016-2024 and a belt-wide GNSS compilation. The result [...]
Fabric- and fluid-constrained ⁴⁰Ar/³⁹Ar geochronology of the northeastern Carajás Province, Amazonian Craton: separating hydrothermalism from Rhyacian and Orosirian reworking of Archean crust
Published: 2026-08-12
Subjects: Geology, Tectonics and Structure
The Carajás Province, southeastern Amazonian Craton, is a polycyclic Archean block in which the ages of rocks, hydrothermal minerals and tectonic fabrics need not coincide. We integrate multiscale structural analysis with fabric-constrained ⁴⁰Ar/³⁹Ar geochronology of amphibole, biotite and white mica selected from mapped fabrics or well-defined hydrothermal assemblages. Although the province [...]
Joint Inversion of Seismic and Geoelectrical Data Targeting Geological Faults
Published: 2026-08-03
Subjects: Earth Sciences, Geophysics and Seismology, Tectonics and Structure
Near-surface geological faults play a crucial role in subsurface systems because they influence fluid flow and transport and can cause geotechnical failure. Topography can sometimes indicate the presence of fault zones, particularly in active tectonic settings where geomorphic features such as triangular facets are preserved. However, particularly for older inactive faults, characteristic surface [...]
Using tectonic block modeling to quantify the impact of potentially–active faults on seismic hazard and risk in western Canada
Published: 2026-07-28
Subjects: Tectonics and Structure
In order to understand the impact of large, potentially active faults on seismic hazard and risk in western Canada, faults in the region are characterized using a geodetic-geologic block model. The results are then integrated into Canada's existing national seismic hazard and risk models. To do this, potentially active faults are mapped to build a block model around them; then, several thousand [...]
The Tarim Mega Impact Event: A Permian (~290 Ma) Mega-Impact Triggering Global Magmatism, the Artinskian Warming Event, and the Central Asian Arc-LIP Belt
Published: 2026-07-20
Subjects: Geochemistry, Geographic Information Sciences, Geomorphology, Geophysics and Seismology, Sedimentology, Stratigraphy, Tectonics and Structure, Volcanology
We propose that an oblique mega-impact by a ferronickel asteroid (~180×100×90 km, 22 km/s, incidence angle 24°) that occurred at ~290 Ma in the present-day Tarim Basin can, through the "thin-target penetration" mechanism, attempt to unify within a single physical framework: (1) the Tarim Large Igneous Province (TLIP) flood basalts; (2) the Pamir–Iran–Turkey arcuate mafic–ultramafic magmatic belt; [...]