Preprints
Filtering by Subject: Geology
Internal waves and bottom currents interactions around mesophotic reefs, southeastern Mediterranean
Published: 2023-01-25
Subjects: Environmental Monitoring, Geology, Marine Biology, Other Environmental Sciences, Sedimentology
Mesophotic reefs are found in water depths greater than 30m and as such are, for the most part, removed from most direct wave activity, notably in the Mediterranean Sea. There, they are protected from anthropogenic impact and serve as a possible refuge for marine biodiversity in a warming ocean. Yet, like any reef, their growth is modulated by the distribution of the sediment they produce and [...]
Lithospheric structure and melting processes in southeast Australia: new constraints from joint probabilistic inversions of 3D magnetotelluric and seismic data
Published: 2023-01-25
Subjects: Geology, Geophysics and Seismology
The thermochemical structure of the lithosphere exerts control on melting mechanisms in the mantle as well as the location of volcanism and ore deposits. Imaging the complex interactions between the lithosphere and asthenospheric mantle requires the joint inversion of multiple data sets and their uncertainties. In particular, the combination of seismic velocity and electrical conductivity with [...]
Exceptional preservation of three-dimensional dunes on an ancient deep-marine seafloor: implications for sedimentary processes and depositional environments
Published: 2023-01-19
Subjects: Geology, Stratigraphy
Depositional and erosional bedforms can be used to reconstruct sedimentary processes and aid paleoenvironmental interpretations. Using exhumed deep-marine strata in the Eocene Aínsa Basin, Spain, we document a 3-dimensional package of dunes; a relatively rarely identified bedform in deep-marine environments. Our analysis shows that the dunes have curvilinear crests in planform, with smaller [...]
The applicability of G-BASE stream sediment geochemistry as a combined geological mapping, and prospective exploration tool for As-Co-Cu-Ni mineralisation across Cumbria, UK.
Published: 2023-01-18
Subjects: Earth Sciences, Geochemistry, Geology, Multivariate Analysis, Physical Sciences and Mathematics, Statistics and Probability
Stream sediment geochemistry is a useful tool to analyse the geochemistry of the local geology within the source catchment area. This has significant applicability within the field of mineral exploration where understanding regional lithological geochemistry is needed, facilitating the identification of critical metal deposits. Successful identification of these deposits is essential to help [...]
Are marl-limestone alternations mainly driven by CaCO3 variations at the astronomical timescale? New insights from extraterrestrial 3He
Published: 2023-01-07
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Sedimentology, Stratigraphy
Marl-limestone alternations are rhythmical inter-bedded deposits that commonly occur in many sedimentological environments. It is quite well established that these lithological variations originate from astronomically-driven climatic variations paced by the Milankovitch cycles of main periods 19, 23, 41, 100 and 405 ka. However, the sedimentological mechanisms involved are not clear: some models [...]
Barometers behaving badly II: A critical evaluation of Cpx-only and Cpx-Liq thermobarometry in variably-hydrous arc magmas
Published: 2022-12-15
Subjects: Earth Sciences, Geochemistry, Geology, Volcanology
The chemistry of erupted clinopyroxene crystals (±equilibrium liquids) have been widely used to deduce the pressures and temperatures of magma storage in volcanic arcs. However, the large number of different equations parametrizing the relationship between mineral and melt compositions and intensive variables such as pressure and temperature yield vastly different results, with [...]
Transgressive rocky coasts in the geological record: Preserved or eroded? Insights from Miocene granitic rocky shorelines and modern examples.
Published: 2022-12-14
Subjects: Earth Sciences, Geology
Most of modern shorelines are in net erosion. Among these, rocky shorelines are commonly punctuated, with alternating high relief cliffs an incised embayments which host “pocket beaches”. While multiple cases of ancient rocky shorelines associated with low relief ravinement surfaces have been documented in the geological record, deposits formed in pocket beaches and joint-cut hollows are more [...]
Correlation of geological complexes of the Khan-Tengri Mountain massif
Published: 2022-12-09
Subjects: Earth Sciences, Geology, Stratigraphy, Tectonics and Structure
Researchers of the border regions of Xinjiang and the Central Asian countries are actively discussing two alternative models for the relationships between the main structural units of the Tianshan mountains. Most researchers believe that the Kyrgyz Middle Tianshan wedges out to the east along the Atbashi-Inylchek-Nalati marginal fault. According to the second hypothesis, the structures of the [...]
Modeling Earthquake-induced Landslide initiation using the Fibre Bundle Model
Published: 2022-12-05
Subjects: Geology, Geomorphology, Geophysics and Seismology, Hydrology
Co-seismic landslides are triggered by strong ground shaking in mountainous areas, resulting in threats to human activity and infrastructure. Methods for physically-based modelling of co-seismic landslide triggering play an important role in disaster prevention and mitigation. Current approaches, however, focus on direct and full failure of sloping rocks and soils, and do not cover the dynamics [...]
An interconnected palaeo-subglacial lake system in the central Barents Sea
Published: 2022-12-03
Subjects: Earth Sciences, Geology, Geomorphology, Glaciology, Sedimentology
Drainage of meltwater beneath an ice sheet influences ice-flow dynamics. To better predict ice sheet behaviour, it is crucial to understand subglacial hydrological processes. Subglacial lakes are important components of the subglacial hydrological system, with many observed and predicted at the beds of contemporary and palaeo-ice sheets. The technical and logistical challenges of studying [...]
Barometers behaving badly: Assessing the influence of analytical and experimental uncertainty on clinopyroxene thermobarometry calculations at crustal conditions
Published: 2022-12-01
Subjects: Earth Sciences, Geochemistry, Geology, Mineral Physics, Volcanology
The composition of clinopyroxene and Clinopyroxene-Liquid (Cpx-Liq) pairs are frequently used to calculate crystallization/equilibration pressures in igneous systems. While canonical uncertainties are often assigned to calculated pressures based on fits to calibration or test datasets, the sources of these uncertainties (and thus ways to reduce them) have not been rigorously assessed. We show [...]
Evolution of intraplate magmatism atop a mantle plume: geochemical and chronological analysis of Shawahit Basalt, Harrat Rahat, Saudi Arabia
Published: 2022-11-15
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Stratigraphy, Tectonics and Structure, Volcanology
Harrat Rahat is the largest volcanic eld in Saudi Arabia and has been active from ~10 Ma to the present day. Due to its close proximity to important population centres, Harrat Rahat's recent eruptions, the Medinah lava flows (< 1.7 Ma), have been extensively studied to identify volcanic risk. However, the evolution of Harrat Rahat's most extensive and oldest lava flows, known collectively as the [...]
The unknown fate of macroplastic in mountain rivers
Published: 2022-11-09
Subjects: Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Geology, Geomorphology, Hydrology, Life Sciences, Natural Resources and Conservation, Sedimentology, Stratigraphy, Sustainability, Terrestrial and Aquatic Ecology, Water Resource Management
Mountain rivers are typically seen as relatively pristine ecosystems, supporting numerous goods (e.g., water resources) for human populations living not only in the mountain regions but also downstream from them. Recent evidence suggests, however, that mountain river valleys in populated areas can be substantially polluted by macroplastic (plastic item > 5 mm). It is, however, unknown how [...]
The missing carbon budget puzzle piece: shallow-water hydrothermal vents contribution to global CO2 fluxes
Published: 2022-11-08
Subjects: Earth Sciences, Geochemistry, Geology, Planetary Biogeochemistry, Volcanology
The release of CO2 gases from volcanoes and their secondary geothermal manifestations are an important contributor to the global carbon budget. While degassing from mid ocean ridges is relatively well-constrained, the contribution of shallow submarine volcanic degassing to the atmosphere is less clear. Shallow-water hydrothermal vents are common seafloor features present at depths shallower than [...]
Kinematic and rheological controls on rift-related fault evolution
Published: 2022-11-07
Subjects: Earth Sciences, Geology, Tectonics and Structure
Continental extension is primarily accommodated by the evolution of normal fault networks. Rifts are shaped by complex tectonic processes and it has historically been difficult to determine the key rift controls using only observations from natural rifts. Here, we use 3D thermo-mechanical, high-resolution (<650 m) forward models of continental extension to investigate how fault network patterns [...]