Preprints
Filtering by Subject: Sedimentology
Discontinuity in Equilibrium Wave-Current Ripple Size and Shape Caused by a Winnowing Threshold in Cohesive Sand-Clay Beds
Published: 2021-09-30
Subjects: Earth Sciences, Geomorphology, Sedimentology
Sediments composed of mixed cohesive clay and non-cohesive sand are widespread in a range of aquatic environments. The dynamics of ripples in mixed sand–clay substrates have been studied under pure current and pure wave conditions. However, the effect of cohesive clay on ripple development under combined currents and waves has not been examined, even though combined flows are common in estuaries, [...]
Early Pliocene Marine Transgression into the Lower Colorado River Valley, Southwestern USA, by Re-Flooding of a Former Tidal Strait
Published: 2021-09-29
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Marine straits and seaways are known to host a wide range of sedimentary processes and products, but the role of marine connections in the development of large river systems remains little studied. This study explores a hypothesis that shallow marine waters flooded the lower Colorado River valley at ~ 5 Ma along a fault-controlled former tidal straight, soon after the river was first integrated [...]
Safety and Belonging in the Field: A Checklist for Educators
Published: 2021-08-19
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Cosmochemistry, Earth Sciences, Education, Environmental Education, Environmental Health and Protection, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Environmental Studies, Fresh Water Studies, Geochemistry, Geographic Information Sciences, Geography, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Higher Education, Human Geography, Hydrology, Life Sciences, Meteorology, Mineral Physics, Natural Resource Economics, Natural Resources and Conservation, Natural Resources Management and Policy, Nature and Society Relations, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Oil, Gas, and Energy, Other Earth Sciences, Other Environmental Sciences, Other Geography, Other Oceanography and Atmospheric Sciences and Meteorology, Other Planetary Sciences, Outdoor Education, Paleobiology, Paleontology, Physical and Environmental Geography, Physical Sciences and Mathematics, Planetary Biogeochemistry, Planetary Geochemistry, Planetary Geology, Planetary Geomorphology, Planetary Geophysics and Seismology, Planetary Glaciology, Planetary Hydrology, Planetary Mineral Physics, Planetary Sciences, Planetary Sedimentology, Remote Sensing, Sedimentology, Social and Behavioral Sciences, Soil Science, Spatial Science, Speleology, Stratigraphy, Sustainability, Tectonics and Structure, Volcanology, Water Resource Management
Ensuring taught fieldwork is a positive, generative, collective, and valuable experience for all participants requires considerations beyond course content. To guarantee safety and belonging, participants’ identities (backgrounds and protected characteristics) must be considered as a part of fieldwork planning and implementation. Furthermore, getting fieldwork right is an important step in [...]
Predicting bottom current deposition and erosion on the ocean floor
Published: 2021-07-28
Subjects: Sedimentology
Mapping sediment deposition and erosion by thermohaline ocean bottom currents is important for the development of ocean infrastructure, future geo resources and understanding the sedimentology of contourites and abyssal dunefields. However, only a limited percentage (estimated 20%) of the ocean floor has been mapped directly through seismic or sonar imaging. To better delineate where zones of [...]
Fluvial sedimentation and its reservoir potential at foreland basin margins: A case study of the Puig-reig anticline (South-eastern Pyrenees)
Published: 2021-07-21
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
Fluvial fans represent one of the dominant sedimentary systems at the active margins of non-marine foreland basins. The Puig-reig anticline at the north-eastern margin of the Ebro Foreland Basin (SE Pyrenees, Spain) exposes continuous outcrops of late Eocene-early Oligocene fluvial deposits, from proximal to medial fluvial fan environments. The proximal deposits, located in the northern limb of [...]
Sandstone body character, river styles, and geomorphology of the lower Eocene Willwood Formation, Bighorn Basin, Wyoming, USA
Published: 2021-07-18
Subjects: Geology, Geomorphology, Sedimentology
The lower Eocene Willwood Formation of the Bighorn Basin, Wyoming, USA, is an alluvial succession with a sand content varying around 25%. It has been studied intensively for palaeontology, palaeoenvironments and palaeoclimates, as well as sedimentological and stratigraphic analysis. Channel dynamics were studied at a relatively low resolution throughout the basin over the geological time from [...]
Stylolites and stylolite networks as primary controls on the geometry and distribution of carbonate diagenetic alterations
Published: 2021-07-18
Subjects: Earth Sciences, Geology, Sedimentology, Stratigraphy, Tectonics and Structure
There is an ongoing debate on whether stylolites act as barriers or conduits for fluids, or even play no role in terms of fluid transport. This problem can be tackled by examining the spatial and temporal relationships between stylolites and other diagenetic products at multiple scales. Using the well-known Lower Cretaceous Benicàssim case study (Maestrat Basin, E Spain), we provide new field and [...]
Carbonate polymorphism controlled by microbial iron redox dynamics at a natural CO2 leakage site (Crystal Geyser, Utah)
Published: 2021-07-07
Subjects: Geochemistry, Geology, Sedimentology
Crystal Geyser (Utah, USA) is a CO2-rich low-temperature geyser that is studied as a natural analog for CO2 leakage from carbon capture and storage (CCS) sites. In order to better constrain the biogeochemical processes influencing CaCO3 precipitation at geological CO2 escape sites, we characterized fast-forming iron-rich calcium carbonate pisoids and travertines precipitating from the fluids [...]
A Model Workflow for GeoDeepDive: Locating Pliocene and Pleistocene Ice-Rafted Debris
Published: 2021-07-02
Subjects: Earth Sciences, Glaciology, Sedimentology
Machine learning technology promises a more efficient and scalable approach to locating and aggregating data and information from the burgeoning scientific literature. Realizing this promise requires provision of applications, data resources, and the documentation of analytic workflows. GeoDeepDive provides a digital library comprising over 13 million peer-reviewed documents and the computing [...]
Paleoenvironmental change recorded in submarine fans: the Eocene-Oligocene climate transition in the Alpine foreland basin
Published: 2021-06-29
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
The Eocene-Oligocene transition (EOT) was a period of considerable environmental change, signifying the transition from Paleocene greenhouse to Oligocene icehouse conditions. Preservation of the sedimentary signal of such an environmental change is most likely in net-depositional environments, such as submarine fans, which are the terminal parts of sedimentary systems. Here, using sedimentary and [...]
Late Quaternary climatic histories from the Hermes Cave, Corinth Rift, Greece
Published: 2021-06-25
Subjects: Earth Sciences, Geochemistry, Geomorphology, Sedimentology, Speleology
The Greek peninsula is located at the crossroads of several major atmospheric circulation patterns and is consequently characterized by high variability in climatic conditions, making it an important location to examine past climate variability. Over the last decades, the focus of many studies in the region has been to unravel Holocene paleoclimatic oscillations and their impact on the [...]
Environmental variability at the margin of the South American Monsoon System recorded by a high-resolution sediment record from Lagoa Dourada (South Brazil)
Published: 2021-06-25
Subjects: Earth Sciences, Geochemistry, Geomorphology, Sedimentology
High-resolution geochemical and sedimentological data have been obtained for a lacustrine sediment record from Lagoa Dourada (South Brazil). Four distinctly different depositional processes were determined: (1) Suspension fallout of fine-grained minerogenic particles transferred via fluvial activity dominates the Early Holocene and relates to open grassland in the catchment area; (2) Activation [...]
Channel, dune and sand sheet architectures of strait-adjacent deltas, Rifian Corridor, Morocco
Published: 2021-06-17
Subjects: Earth Sciences, Geology, Sedimentology, Stratigraphy
Sea strait geographies amplify tidal currents, which can result in the formation of tidal strait deposits with a symmetrical facies arrangement. It can be problematic to distinguish such confined tidal strait deposits from strait systems that developed in less constricted settings. To push a more robust differentiation between the confined tidal strait model and a model for less constricted tidal [...]
Microstructure and fluid flow in the vicinity of basin bounding faults in rifts – the Dombjerg Fault, NE Greenland rift system
Published: 2021-06-17
Subjects: Earth Sciences, Geology, Sedimentology, Tectonics and Structure
Faults commonly form loci for high fluid flux in sedimentary basins, where fluids, rocks and deformation processes frequently interact. Here, we elucidate the interaction of fluid flow, diagenesis and deformation near basin-bounding faults in sedimentary basins through a study in the vicinity (0-3.5 km) of the Dombjerg Fault in the NE Greenland rift system. Due to fault-controlled fluid [...]
OpenOBS: Open-source, low-cost optical backscatter sensors for water quality and sediment-transport research
Published: 2021-06-17
Subjects: Environmental Monitoring, Fluid Dynamics, Fresh Water Studies, Geomorphology, Oceanography, Sedimentology, Water Resource Management
Optical backscatter sensors (OBSs) are commonly used to measure the turbidity, or light obscuration, of water in fresh and marine environments and various industrial applications. These turbidity measurements are commonly calibrated to yield total suspended solids (TSS) or suspended sediment concentration (SSC) measurements for water quality, sediment transport, and diverse other research and [...]