Preprints
Filtering by Subject: Geology
Archaean basalts record evidence of lithospheric extension prior to cratonisation
Published: 2025-05-23
Subjects: Earth Sciences, Geochemistry, Geology, Geophysics and Seismology
The dynamics of Earth’s early mantle remain enigmatic. A wide range of tectonic settings have been proposed for the Archaean eon prior to cratonisation, a time from which few samples are preserved in the geological record. Here, we reexamine this topic by estimating temperatures and depths of melt generation in the late Archaean mantle using a new geochemical data compilation of mafic igneous [...]
Paleo extreme waves in the North Atlantic: geological evidence from Sal Island, Cape Verde Archipelago.
Published: 2025-05-21
Subjects: Earth Sciences, Geology, Geomorphology
The northwestern coast of Sal Island (Cape Verde Archipelago) is characterized by a rocky shoreline that is regularly impacted by Atlantic swells exceeding 4 m in height and 20 s in period. Yet, the only significant geomorphic expression of wave action is an extensive boulder ridge situated atop a rocky cliff, up to 80–100 m inland and between 10 and 15 m above present sea level. The presence of [...]
Decision-making under uncertainty for shallow geothermal systems in complex subsurface settings: application to a low-transmissivity aquifer
Published: 2025-05-07
Subjects: Geology, Hydrology, Natural Resources and Conservation, Sustainability
Excess thermal energy can be stored in the subsurface and recovered when needed to heat and cool buildings sustainably. Aquifer thermal energy storage systems (ATES) are gaining popularity worldwide. Most operational systems are located in thick productive aquifers. Their efficiency and wide applicability have been proven and there is now a tendency to explore more complex settings. Aquifers with [...]
The Apalachicola Barrier Island complex: a benchmark for MIS 5e (125 ka) sea-level oscillations?
Published: 2025-05-05
Subjects: Earth Sciences, Geology, Geomorphology
Coastal sandy barrier systems develop under moderate wave energy, sufficient sediment supply, and adequate accommodation space, and can preserve critical paleoenvironmental records of past sea-level variations, climatic shifts, and storm histories within their geomorphological and stratigraphic frameworks. Beach ridges, identifiable on both horizontal (ridge-swale morphology) and vertical [...]
A SCALABLE MACHINE LEARNING MODELLING TOOL FOR MAPPING LANDSLIDE RUNOUT USING A CASE STUDY IN HAWKES BAY, NEW ZEALAND
Published: 2025-05-01
Subjects: Climate, Earth Sciences, Geology, Geotechnical Engineering, Other Statistics and Probability
Understanding landslide runout is crucial for land use planning, utility networks, and assessing infrastructure resilience on slopes. Recent guidance recommends incorporating landslide runout models along with climate change implications when assessing land for development. The advancement of machine learning (ML) techniques can offer new insights and a tool to be used alongside current methods. [...]
Application of mud gas analysis for reservoir evaluation
Published: 2025-05-01
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Mud gas, which is usually used for monitoring the safety of the wells while drilling, can also be used as a formation evaluation tool. This study aims to analyse mud gas ratios and compare them with the traditional formation evaluation tools, such as resistivity. The analysis of four wells, either exploration or development wells, located in differing geological settings, shows that [...]
Reliability of Contrast-Based Automated Fracture Detection from Decimeter Resolution Aerial Imagery
Published: 2025-04-30
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Geology, Geotechnical Engineering, Other Engineering, Physical Sciences and Mathematics, Tectonics and Structure
Aerial imagery that captures outcrop exposures of rocks enables the characterization of structural discontinuities such as faults and fractures across large and difficult-to-access areas. These datasets provide an opportunity to analyze the characteristics of fault and fracture networks as analogues for the subsurface. The application of automated interpretation methods to imagery has the [...]
Earthquake faults recorded in the near-shore bathymetry of Japan's back-arc
Published: 2025-04-27
Subjects: Geology, Geomorphology, Geophysics and Seismology, Tectonics and Structure
The eastern margin of the Sea of Japan is a zone of great seismic and tsunami hazard due to multiple offshore and nearshore reverse faults as shown by the 2024 Mw 7.5 Noto Peninsula Earthquake. Here we compare coseismic deformation of the 2024 Noto Peninsula Earthquake with 4767 individual marine terraces spanning the last Myr. This reveals that the earthquake faults started slipping between 326 [...]
Calcium isotope constraints on Mesoarchean seawater
Published: 2025-04-24
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Sedimentology
The cause of the Great Oxidation Event ~2.4 billion-years-ago (Ga) is hotly debated. Recent models favor the emergence of continents as driving the event. However, we suggest that extensive shallow-marine carbonate platforms existed in the Mesoarchean. This conclusion is based on Ca isotopes from 2.8 Ga carbonate rocks, that constrains the Ca isotope value of Mesoarchean seawater to -0.5‰ [...]
Deep source regions for Patagonia backarc volcanism imaged by finite frequency body wave tomography
Published: 2025-04-08
Subjects: Earth Sciences, Geochemistry, Geology, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
The subduction of Chile Ridge beneath South America beginning 12-16 Myr ago opened a gap in the subducting slab beneath southern Patagonia, which migrated northward and is located today at 46oS. Geodynamic processes associated with the slab window are poorly understood. Here we apply finite-frequency P and S body wave tomography to seismic data from several temporary arrays as well as regional [...]
A New Fault Model for the 1933 Long Beach Earthquake, Long Beach Area, Southern California
Published: 2025-04-05
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics
Newly identified thrust faults and their corresponding thrust sheets, combined with recent micro-earthquake epicenters, better explain anomalous rupture data observed during the 1933 Long Beach Earthquake than previous models based exclusively on Newport-Inglewood Fault Zone strike-slip faulting. A high-quality 45 km2 3D seismic dataset was recorded in 2017, centered along the Seal Beach [...]
A new hypothesis for bimodal volcanism in the Kermadec Arc
Published: 2025-03-29
Subjects: Geochemistry, Geology, Physical Sciences and Mathematics, Volcanology
Bimodal volcanism of basaltic and rhyolitic magmas in the Kermadec Arc has been attributed to the fractional crystallization of basaltic sources. However, new evidence from the Kibblewhite Volcano reveals two distinct differentiation pathways originating from mantle-derived basaltic and andesitic primary magmas. Here we employ geothermobarometric estimations, mass-balance calculations, and [...]
The Petrology, Geochemistry, and Origin of the East Australian Potassic Suite: Bulk Chemistry and Genesis
Published: 2025-03-26
Subjects: Earth Sciences, Geochemistry, Geology, Volcanology
The Eastern Australian Potassic Suite (EAPS) is an alkaline volcanic province made up of over 20 widely dispersed outcrops that extend almost 700 km, forming the southern portion of the world’s longest continental hotspot track, the Cosgrove track. In contrast to the large basaltic volcanic complexes to the east and north, the EAPS occurs exclusively as mafic potassium–rich occurrences with [...]
Weakening of AMOC linked to past Greenland Ice Sheet retreat
Published: 2025-03-21
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Geochemistry, Geology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Paleontology, Physical Sciences and Mathematics
A weakening of the Atlantic Meridional Overturning Circulation (AMOC) is predicted to occur under multiple scenarios of future warming. However, the effect of meltwater from a decaying Greenland Ice Sheet (GrIS) on AMOC is uncertain. Using a basin-wide network of North Atlantic sediment cores, we show that the largescale melting of the GrIS during a previous interglacial (Marine Isotope Stage 11c [...]
Origin of the Harappan Ernestites: Fabrication and Raw Materials
Published: 2025-03-17
Subjects: Geochemistry, Geology, Other Earth Sciences
Significant developments in stone bead technology in South Asia, including drilling techniques, happened during the Harappan civilization. Among the stone drill bits used for bead making, long and constricted cylindrical drill bits made from a unique stone named Ernestite were exclusive to the Harappan civilization. Most Ernestites have been discovered in the Harappan cities in Gujarat, India. [...]