Preprints
Filtering by Subject: Sedimentology
Seafloor character of the Roman Rock area in False Bay, South Africa
Published: 2024-10-04
Subjects: Geology, Sedimentology
A 12 km2 area off Simon's Town in NW False Bay, South Africa, was surveyed using side-scan sonar and a single-beam echosounder. The survey revealed six distinct patterns of acoustic reflectivity or acoustic facies. The first facies show Cape Peninsula Granite outcrops, matching onshore patterns, with lineaments reflecting the principal WNW-ESE joint direction. The second facies indicate [...]
Seismic Characterization of Carbonate Stringers using Machine Learning techniques: an example from the Western Flank of South Oman Salt Basin
Published: 2024-10-03
Subjects: Geology, Geophysics and Seismology, Sedimentology
Carbonate stringers are defined as a slab of carbonate bodies encased inside salt. In Oman, the intra-salt carbonate stringers are a very common target, especially in South Oman Salt Basin (SOSB). These stringers contain a large amount of hydrocarbon resources. In this study, the behavior of carbonate stringer bodies hosted in Ara salt structures from the SOSB is investigated. Both synthetic and [...]
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 [...]
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, [...]
Taphonomic Controls on a Multi-Element Skeletal Fossil Record
Published: 2024-08-02
Subjects: Earth Sciences, Life Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology
Animals with multi-element skeletons, including the vertebrates, echinoderms, and arthropods, are some of the most biodiverse and ecologically important animal groups. Understanding the relative impact of the myriad geological and biological factors which impact on the quality of multi-element skeletal fossils is thus crucial for disentangling perceived changes in biodiversity through time and [...]
Evolution of Fluvial Landscapes during the Eocene-Oligocene Transition in Central North America: Reconstructions from Toadstool Geologic Park, Nebraska, U. S. A.
Published: 2024-06-14
Subjects: Earth Sciences, Sedimentology, Stratigraphy
Rivers drive geomorphic change at Earth’s surface by transporting sediment from mountains to sedimentary basins. They are sensitive to changes in water and sediment flux driven by tectonism, climatic perturbation and or volcanism. We characterized changes in fluvial landscapes during a major Cenozoic cooling event, the Eocene-Oligocene Transition (EOT) at 33.9 Ma. The EOT is characterized by a [...]
Paleohydrology of North American Catchments and Rivers at the Onset of the Eocene-Oligocene Climate Transition: Reconstructions from Fluvial Strata of the White River Group, Toadstool Geologic Park, Nebraska
Published: 2024-06-14
Subjects: Earth Sciences, Geology, Sedimentology, Stratigraphy
Member of the Brule Formation of the White River Group at Toadstool Geologic Park in Nebraska. Our approach combined descriptive and quantitative methods to reconstruct river flow, sediment transport, channel dynamics, floodplain behavior, and catchment-scale moisture variability and ecosystem function. We found that rivers were ephemeral, with peak flow depths and widths of approximately 2.5 m [...]
Evolution and architecture of an overbank in an ocean-facing canyon-fill.
Published: 2024-05-21
Subjects: Earth Sciences, Geology, Sedimentology
Submarine canyon-fills comprise substantial volumes of thin-bedded successions deposited by sediment gravity flows that are either stripped or overspill from adjacent channels into highly confined, topographically complex overbank settings. Here, we document the Punta Baja Formation, a rare example of an exhumed canyon-confined overbank succession with good 3D constraints from the Mesozoic [...]
The fate of bars in braided rivers
Published: 2024-05-05
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Ancient river deposits are important archives of past landscape conditions on planetary surfaces. On Earth, they host valuable groundwater, energy resources, and carbon-storage potential. Reconstructing details of paleochannel forms and movements refines our understanding of the controls on river behavior under different climate, landcover, and tectonic conditions, and improves predictions and [...]
How do ancient mass-transport complexes influence subsequent failure events? A case study from the Kangaroo Syncline, offshore NW Australia
Published: 2024-05-03
Subjects: Geology, Geomorphology, Sedimentology
Mass-transport complexes (MTCs) are common features in all continental margins. In some passive margins, accumulations of stacked MTCs indicate repeated slope failure, which raises the question of whether MTC emplacement may influence or even pre-condition, subsequent slope failures. Here, we use 3D seismic reflection data from the Kangaroo Syncline, NW Australia, to investigate how pre-existing [...]
Controls on mesophotic carbonate facies and sediment distribution across the Maltese shelf, central Mediterranean Sea
Published: 2024-05-02
Subjects: Other Environmental Sciences, Sedimentology
Although ~20% of global carbonate occurs on extra-tropical shelves, our understanding of these depositional environments still lags far behind that of tropical carbonate platforms. The Maltese shelf in the central Mediterranean offers an opportunity to study in situ facies distribution in a light-dominated extra-tropical carbonate platform and the factors controlling them. The Maltese shelf [...]
The potential of terrestrial and aquatic molluscs for the temporal analysis of Deckenschotter deposits and younger Quaternary sediments from the Swiss Plateau
Published: 2024-05-02
Subjects: Earth Sciences, Geology, Geomorphology, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Soil Science, Stratigraphy, Terrestrial and Aquatic Ecology
Evolution and architecture of an exhumed ocean-facing coarse-grained submarine canyon fill, Baja California, Mexico
Published: 2024-04-15
Subjects: Earth Sciences, Geology, Sedimentology, Stratigraphy, Tectonics and Structure
Present day submarine canyons are active conduits for large volumes of sediment, carbon, and pollutants from continents to oceans. However, the evolution of submarine canyons over geological timescales remains poorly understood due to their erosional nature and low preservation potential. The Late Cretaceous Punta Baja Formation represents a well-preserved submarine canyon-fill on a [...]
Pleistocene shifts in Great Basin hydroclimate seasonality govern the formation of lithium-rich paleolake deposits
Published: 2024-04-10
Subjects: Earth Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Paleobiology, Sedimentology
Southwestern North America is currently experiencing a multidecadal megadrought, with severe consequences for water resources. However, significant uncertainty remains about how precipitation will change in the 21st century in this semi-arid region. Paleoclimatic records are essential for both contextualizing current change, and for helping constrain the sensitivity of regional hydroclimate to [...]