Preprints
Filtering by Subject: Geology
Assessing the timing of deep ocean oxygenation from uranium elemental and isotopic compositions of ophiolites
Published: 2024-09-26
Subjects: Earth Sciences, Geochemistry, Geology
The concentration of dissolved oxygen in the deep oceans has varied over Earth History, with the timing of the transition from anoxic to oxic deep oceans debated. Under modern-day, oxic, deep ocean conditions, alteration of the upper sections of mafic oceanic crust with U-rich seawater leads to U enrichment, low Th/U ratios, and heterogeneous 238U/235U ratios relative to fresh mid-ocean ridge [...]
Al Hawi, a 4-km-wide impact structure in northern Saudi Arabia
Published: 2024-09-23
Subjects: Astrophysics and Astronomy, Earth Sciences, Geology, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Physics, Planetary Geology, Planetary Sciences, The Sun and the Solar System
The northern region of Saudi Arabia hosts several impact craters and structures. This paper describes the discovery of a 4-km-wide complex impact structure located in the paleozoic sedimentary rocks of northern Saudi Arabia 210 kilometers north east of the city of Tabuk. The impact structure is composed of a central peak displaying intense folding and shock metamorphism surrounded by an inner [...]
Challenges and Opportunities of Data Driven Advance Classification of Hard Rock TBMs
Published: 2024-09-21
Subjects: Applied Statistics, Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Geology, Geotechnical Engineering
Tunnel Boring Machines (TBMs) have revolutionized tunneling industry and are currently the dominant method of tunneling in all ground types including soil and rock. Traditional approaches to TBM advance classification, however, rely heavily on subjective assessments by onsite personnel, which are often hampered by limited access to the excavation face and discontinuous observation intervals. [...]
A new expression for fluid factor using AVO intercept and gradient: theory and application on deep marine reservoir
Published: 2024-09-18
Subjects: Geology, Geophysics and Seismology, Oil, Gas, and Energy
Numerous AVO fluid indicators have been introduced and proven to be sensitive to hydrocarbon presence. Mathematically, fluid indicators measure the deviation of seismic responses of hydrocarbon-saturated reservoirs from their background in a specific domain. We introduce a new expression for the fluid factor commonly used in AVO analysis and interpretation. The expression is a function of common [...]
Evidence supporting a broader than previously thought influence of solar activity over Earth system’s processes. Discussion of a possible mechanism.
Published: 2024-09-08
Subjects: Atmospheric Sciences, Earth Sciences, Geochemistry, Geology, Geophysics and Seismology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Tectonics and Structure, Volcanology
In this article, I show lines of evidence supporting a modulation of volcanic activity and some weather phenomena by solar wind conditions in the near-Earth environment. On a daily timescale, a correlation is found between the LP earthquake activity of Kilauea volcano, related to magma transport, and the Bx component of the interplanetary magnetic field as measured in the OMNI database for [...]
Simultaneous deformation along the Main Ethiopian Rift and associated transversal lineaments: an analogue modelling perspective
Published: 2024-08-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The interaction between the NE-SW striking Main Ethiopian Rift (MER) and the E-W oriented Yerrer-Tullu Wellel Volcano-tectonic lineament (YTVL) represents one of the least understood tectonic problems in the East African Rift System. Despite the numerous studies that have been conducted in the region, the following questions still remain to be answered: did the MER and YTVL evolve simultaneously? [...]
How much is enough? Uncertainty aware sample mass determination of coarse-grained soils for particle size analyses
Published: 2024-08-23
Subjects: Applied Statistics, Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Monitoring, Geology, Geomorphology, Geotechnical Engineering, Hydraulic Engineering, Hydrology, Other Civil and Environmental Engineering, Other Earth Sciences, Probability, Sedimentology, Soil Science, Statistical Models, Statistics and Probability, Stratigraphy
Determining particle size distributions (PSD) of soils is a basic first step in many geotechnical analyses and guidance is given in different national standards. For ambiguous reasons, the recommended required minimum sample mass (m_min) for the PSD-analyses of soils with a main component of gravel or greater is always based on equations including the soil's maximum grain diameter (D_max). We [...]
The Origin of Forearc Depressions
Published: 2024-08-23
Subjects: Earth Sciences, Geology, Sedimentology, Tectonics and Structure
Forearc depressions form over continental subduction zones with young, slowly subducting slabs and thick trench fills. They are bound seaward by a coast range and landward by a volcanic arc such that subsidence in forearc depressions occurs between orogens and in areas characterized by plate convergence. We propose a model for forearc depression formation based on geophysical and seismic data [...]
Influence of temperature on the residual shear strength of landslide soil: role of the clay fraction
Published: 2024-08-12
Subjects: Geology, Geotechnical Engineering
The shear strength is a fundamental parameter of soil that controls the occurrence and propagation of landslides. In pure clays, it depends on temperature according to the mineralogy, stress history, and hydro-mechanical boundary conditions. Landslide soils, however, are typically very heterogeneous and have a variable content of fines. The sensitivity of the residual shear strength of [...]
Rapid Fault Leakage Modeling for CO2 Storage in Saline Aquifers
Published: 2024-08-12
Subjects: Chemical Engineering, Earth Sciences, Engineering, Geology, Petroleum Engineering, Physical Sciences and Mathematics, Risk Analysis
Simulating the fluid flow along fault zones at different scales is essential for predicting the CO2 leakage and containment during injection and storage. However, this can be challenging, especially in the early stages of a storage project when knowledge of the reservoir and caprock is limited and the cost of obtaining the relevant data is high. This study proposes a tool for fast screening of [...]
Reconstructing past sea-level changes from storm-built beach ridges
Published: 2024-08-12
Subjects: Earth Sciences, Geology, Geomorphology, Sedimentology
Storm-built beach ridges, built by waves on sedimentary coasts, can be used as geomorphological indicators of past sea level. However, quantifying the relationship between the geomorphological elements of the ridge and the paleo sea level at the time of deposition is difficult, as a beach ridge is primarily correlated to wave energy and only secondarily to the position of sea level. In this work, [...]
The cyclical nature of normal fault growth: Insights from 4D analogue models
Published: 2024-08-10
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Exploring how normal faults evolve is important for understanding the dynamic processes underlying the initiation and evolution of rift systems. Early-stage fault growth has been largely under-explored due to resolution limitations in seismic reflection data and the lack of three-dimensional exposures in the field. Physical analogue modelling offers a unique way to visualize and analyse [...]
Tomotectonics of Cordilleran North America since Jurassic times: double-sided subduction, archipelago collisions, and Baja-BC translation
Published: 2024-07-27
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Tomotectonics uses deep mantle structure in order to hindcast paleo-trenches, by spatially superposing subducted lithosphere (slabs) imaged by seismic tomography with plate reconstructions at the surface. The two geophysical datasets combined make predictions about geologic events, specifically about volcanic arcs and their collisions with continents. The tomotectonic null hypothesis is simple, [...]
geodl: An R package for geospatial deep learning semantic segmentation using torch and terra
Published: 2024-07-18
Subjects: Geology, Geomorphology, Numerical Analysis and Scientific Computing, Programming Languages and Compilers
Convolutional neural network (CNN)-based deep learning (DL) methods have transformed the analysis of geospatial, Earth observation, and geophysical data due to their ability to model spatial context information at multiple scales. Such methods are especially applicable to pixel-level classification, or semantic segmentation, tasks. A variety of R packages have been developed for processing and [...]
Volcanic arc structure controlled by liquid focusing from the slab — evidence from boron isotopes and trace elements
Published: 2024-07-16
Subjects: Earth Sciences, Geochemistry, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
The rates and pathways of material transport from subducting plates to arc volcanoes control the long-term chemical evolution of the atmosphere, continents, and mantle. Arc magma compositions are commonly used as proxies for the state of the slab directly below a volcanic vent, under the assumption of vertical transport from the slab to the surface. Here, we present new boron (B) isotope and [...]