Preprints

Filtering by Subject: Stratigraphy

Integration of Deterministic Seismic inversion with Machine Learning for Reservoir Characterization

Mohammed Farfour

Published: 2024-10-04
Subjects: Geology, Geophysics and Seismology, Stratigraphy

Seismic inversion plays a key role in reservoir characterization. The inversion allows interpreters to transfer data from interface properties to layers and physical properties. Various deterministic approaches are available for interpreters to achieve this objective, including model-based, trace-based, recursive approaches, etc. Machine learning methods are increasingly adopted in reservoir [...]

How much is enough? Uncertainty aware sample mass determination of coarse-grained soils for particle size analyses

Georg H. Erharter, Santiago Quinteros, Diana Cordeiro, et al.

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 [...]

Evolution of Fluvial Landscapes during the Eocene-Oligocene Transition in Central North America: Reconstructions from Toadstool Geologic Park, Nebraska, U. S. A.

Queenie Chang, Anjali M Fernandes, Michael T Hren, et al.

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

Anjali M Fernandes, Michael T Hren, Queenie Chang, et al.

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 [...]

Bayesian Inversion with TimeOptMCMC

Stephen Richard Meyers

Published: 2024-05-16
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Statistical Methodology, Stratigraphy

TimeOptMCMC (Meyers and Malinverno, 2018) is a Bayesian approach for evaluating cyclostratigraphic records that quantitatively links geologic data with astronomical theory. This manuscript provides an introductory guide for conducting a TimeOptMCMC Bayesian inversion, following the approach of Meyers and Malinverno (2018). The purpose of this guide is to help users identify an appropriate data [...]

The fate of bars in braided rivers

Safiya Alpheus, Elizabeth A Hajek

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 [...]

The potential of terrestrial and aquatic molluscs for the temporal analysis of Deckenschotter deposits and younger Quaternary sediments from the Swiss Plateau

Nigel Thew

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

Max Bouwmeester, Ian Kane, David Hodgson, et al.

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 [...]

WITHDRAWN: The potential of terrestrial and aquatic molluscs for the temporal analysis of Deckenschotter deposits and younger Quaternary sediments from the Swiss Plateau

Nigel Thew

Published: 2024-02-08
Subjects: Earth Sciences, Geology, Geomorphology, Paleobiology, Paleontology, Sedimentology, Stratigraphy

An aminostratigraphy for the Quaternary of the Swiss Plateau

Kirsty Penkman, Nigel Thew, Samantha Presslee, et al.

Published: 2024-02-08
Subjects: Analytical Chemistry, Earth Sciences, Geochemistry, Other Earth Sciences, Stratigraphy

Here we develop an amino acid chronology to help establish a dated sequence for the important Early Pleistocene Höhere and Tiefere Deckenschotter lithostratigraphic units, as well as other Quaternary deposits from the Swiss Plateau. Age discrimination is possible between the Quaternary sites from the Swiss Plateau in six different biominerals: Bithynia opercula, shell fragments from Fruticola, [...]

Facies models for rocky shorelines and their application to transgressed basement highs in the North Sea.

Josep Maria Puig Lopez, John Howell

Published: 2024-01-28
Subjects: Earth Sciences, Geology, Geomorphology, Sedimentology, Stratigraphy

Rocky shorelines form where basement highs are eroded and flooded during marine transgressive events. Despite the Mesozoic North Sea rift generated numerous platform margins and rotated fault blocks which acted as basement highs, rocky shoreline deposits have not been previously reported. In the rock record rocky shoreline deposits are usually represented by thin conglomerates overlying major [...]

River Floodplains, Organic Carbon, and Paleoclimate: How River Dynamics Impart Biases in the Biogeochemical Climate Record of Terrestrial Landscapes

Anjali M Fernandes, Michael T Hren, Virginia B. Smith, et al.

Published: 2024-01-28
Subjects: Earth Sciences, Geochemistry, Geomorphology, Hydrology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy

River floodplains can be both sources and sinks for organic carbon. In the sedimentary record, geochemical signatures of terrestrial water availability record climate and ecology along river corridors in deep time. However, paleoenvironmental reconstructions are often confounded by the complex dynamics of organic carbon residence, entrainment, and deposition in a fluvial system. As alluvial [...]

Will the ‘Anthropocene’ finally be formalized?

Valentí Rull

Published: 2023-12-08
Subjects: Geology, Stratigraphy

A proposal for the formalization of the ‘Anthropocene’ as a new geological epoch following the Holocene has just been submitted (31 October 2023) to the International Commission on Stratigraphy (ICS). This proposal, prepared by the Anthropocene Working Group (AWG) after 13 years of discussions, places the beginning of the ‘Anthropocene’ in the mid-20th century, and considers that the [...]

Downsystem Grain-Size Trends and Mass Balance of an Ancient Wave-Influenced Sediment Routing System: Middle Jurassic Brent Delta, Northern North Sea, Offshore UK and Norway

Ikenna Okwara, Gary J Hampson, Alexander C Whittaker, et al.

Published: 2023-11-14
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy

We reconstruct upsystem-to-downsystem grain-size variations in the sediment routing systems of the data-rich Middle Jurassic Brent Group of the northern North Sea, using published stratigraphic, thickness, palaeogeographic, provenance and age constraints combined with representative core and wireline-log data. Facies associations provide a textural proxy for gravel, sand and mud grain-size [...]

Changes in mesophotic carbonate-platform export across the end of the last glacial cycle (Saya de Malha Bank, western Indian Ocean)

Or M. Bialik, Christian Betzler, Juan Carlos Braga Alarcón, et al.

Published: 2023-11-07
Subjects: Biogeochemistry, Geochemistry, Natural Resources and Conservation, Other Earth Sciences, Other Environmental Sciences, Paleobiology, Sedimentology, Stratigraphy

The export of neritic material from the top of carbonate platforms is a key process in the construction of their slopes. However, our knowledge of the supply pattern of materials from platforms is dominantly based on platforms lying in the euphotic zone during the present sea-level highstand. This is a somewhat biased perspective as through geological time not all platforms were euphotic. The [...]

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