Preprints
Filtering by Subject: Sedimentology
Quantifying natural delta variability using a multiple-point geostatistics prior uncertainty model
Published: 2018-09-30
Subjects: Artificial Intelligence and Robotics, Civil and Environmental Engineering, Computer Sciences, Earth Sciences, Electrical and Computer Engineering, Engineering, Environmental Engineering, Geology, Geomorphology, Other Civil and Environmental Engineering, Other Engineering, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Theory and Algorithms
We address the question of quantifying uncertainty associated with autogenic pattern variability in a channelized transport system by means of a modern geostatistical method. This question has considerable relevance for practical subsurface applications as well, particularly those related to uncertainty quantification relying on Bayesian approaches. Specifically, we show how the autogenic [...]
A revised chronostratigraphic framework for the Aptian of the Essaouira-Agadir Basin, a candidate type section for the NW African Atlantic Margin.
Published: 2018-09-29
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The Essaouira-Agadir Basin (EAB) of Morocco contains the most extensive exposure of Aptian to Lower Albian strata onshore the NW African Atlantic Margin. This paper documents the first high-resolution, multi-disciplinary stratigraphic approach for the Aptian to Lower Albian on the NW African Atlantic Margin. Previous biostratigraphic work almost exclusively relied on long-distance correlation of [...]
Wind tunnel tests inform Ammophila planting spacing for dune management
Published: 2018-09-24
Subjects: Biology, Earth Sciences, Environmental Sciences, Geology, Geomorphology, Life Sciences, Natural Resources Management and Policy, Physical Sciences and Mathematics, Sedimentology
Coastal dunes are invaluable natural resources that bu er upland areas. Vegetation is key in dune development and stabilization. Dunes form with sufficient wind, sand source, and obstruction; plants are the ideal obstruction. Storms o en erode foredunes and coastal managers replant vegetation to re-establish the necessary obstruction for sand accretion and dune growth. We used a wind tunnel to [...]
Reactionary fence installation for post-Superstorm Sandy dune recovery
Published: 2018-09-24
Subjects: Biology, Earth Sciences, Environmental Monitoring, Environmental Sciences, Life Sciences, Natural Resources and Conservation, Physical Sciences and Mathematics, Sedimentology, Sustainability
Dunes are invaluable to coastal areas as dynamic buffers to erosion during high tides and storms, but do not accrue naturally in developed areas without assistance. Wood paling fencing is commonly used to cultivate dune development and thereby increase the protection afforded to coastal areas. In 2012, Superstorm Sandy devastated the mid-Atlantic, especially New Jersey where many areas are still [...]
A New Mechanism for Terrace Formation in Submarine Canyons
Published: 2018-09-24
Subjects: Earth Sciences, Education, Engineering, Geology, Geomorphology, Life Sciences, Physical Sciences and Mathematics, Planetary Geomorphology, Planetary Sciences, Planetary Sedimentology, Sedimentology, Stratigraphy
Deep canyons on Earth occur in both terrestrial and submarine environments, where they are carved by actively incising channels. Apparently similar flights of unpaired terraces, seen at the inside of bends in incised sinuous channels, are also common in both environments. Here we demonstrate a new mechanism for terrace formation that we believe is unique to settings where sediment transporting [...]
Backwater Controls on the Sedimentology, Kinematics and Geometry of Bar Deposits in Coastal Rivers
Published: 2018-09-24
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Geology, Geomorphology, Hydrology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The backwater reach of coastal rivers is associated with considerable spatial and temporal variability in water and sediment flux. Here we test the hypothesis that the spatial and temporal variability in water flux and particle sizes in transport result in systematic changes in the geometry of bank-attached bars across the backwater transition. Measured transverse slopes of bank-attached bars in [...]
Grand Challenges (and Great Opportunities) in Sedimentology, Stratigraphy, and Diagenesis Research
Published: 2018-09-23
Subjects: Biogeochemistry, Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Technological advances make these exciting times for geoscientists studying Earth surface processes, their depositional products, and interactions with the biosphere, hydrosphere, atmosphere, and lithosphere; from monitoring contemporary sediment transport processes to interpretation of sedimentary archives that record ancient environmental changes. We set out three research challenges: 1) [...]
Complex and cascading triggering of submarine landslides and turbidity currents at volcanic islands revealed from integration of high-resolution onshore and offshore surveys
Published: 2018-09-22
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Hydrology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Volcanology
Submerged flanks of volcanic islands are prone to hazards including submarine landslides that may trigger damaging tsunamis and fast-moving sediment-laden seafloor flows (turbidity currents) that break critical seafloor infrastructure. Small Island Developing States are particularly vulnerable to these hazards due to their remote and isolated nature, small size, high population densities and weak [...]
Using polygonal layer-bound normal faults as tools to delimit clastic reservoirs in the Levant Basin offshore Lebanon
Published: 2018-08-19
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Tectonics and Structure
The Levant Basin offshore Lebanon contains an array of layer-bound normal faults in the Oligo-Miocene units. The faults are believed to have nucleated in soft-grained sediments similar to polygonal fault systems worldwide, and as a result are influenced by lithological heterogeneities in the host rock unit. We used 3D seismic data and amplitude extraction from offshore Lebanon to map deepwater [...]
Using bar preservation to constrain reworking in channel-dominated fluvial stratigraphy
Published: 2018-08-16
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Fluvial deposits comprising more than 80% channel facies are often thought to have accumulated during intervals of relatively slow subsidence in sedimentary basins. This interpretation stems from the conceptual model that migrating and avulsing rivers rework their own deposits during times of limited accommodation creation, preferentially removing and bypassing fine floodplain deposits. [...]
Quantification of the Bed-scale Architecture of Submarine Depositional Environments and Application to Lobe Deposits of the Point Loma Formation, California
Published: 2018-08-12
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
As of August 2018, this work is in review in "The Depositional Record", a journal from the IAS (International Association of Sedimentologists) Submarine-fan deposits form the largest sediment accumulations on Earth and host significant reservoirs for hydrocarbons. While many studies of ancient fan deposits qualitatively [...]
Characterisation of submarine depression trails driven by upslope migrating cyclic steps: Insights from the Ceará Basin (Brazil)
Published: 2018-08-08
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
Circular to elliptical topographic depressions, isolated or organized in trails, have been observed on the modern seabed in different contexts and water depths. Such features have been alternatively interpreted as pockmarks generated by fluid flow, as sediment waves generated by turbidity currents, or as a combination of both processes. In the latter case, the dip of the slope has been [...]
New evidence for a major late Quaternary submarine landslide on the external western levee of Laurentian Fan
Published: 2018-08-07
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The Laurentian Fan is one of the largest submarine fans on the western margin of the North Atlantic. Recently acquired high-resolution multibeam bathymetric data (60 m horizontal resolution) reveal a major mass transport deposit (MTD) on the Western Levee of Western Valley (WLWV), covering >14 000 km2 in water depths from 3900 m to >5000 m. Typical submarine landslide features are observed [...]
Shark-fins: overturned patterns linked to shear instabilities at the flow-bed boundary. Examples from the deposits of the 2006 pyroclastic currents at Tungurahua volcano (Ecuador)
Published: 2018-08-06
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Volcanology
Enigmatic structures grouped under the term "shark-fins" are documented in laminated deposits of pyroclastic currents. They consist of an overturning of a few laminae on a decimeter scale, forming overbent "flames" or convolute laminae, which occur in successive, periodic patterns. More than 200 shark-fins were investigated and measured in cross-laminated deposits from the 2006 pyroclastic [...]
Pyroclastic dune bedforms: macroscale structures and lateral variations. Examples from the 2006 pyroclastic currents at Tungurahua (Ecuador)
Published: 2018-08-06
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Volcanology
Pyroclastic currents are catastrophic flows of gas and particles triggered by explosive volcanic eruptions. For much of their dynamics, they behave as particulate density currents and share similarities with turbidity currents. Pyroclastic currents occasionally deposit dune bedforms with peculiar lamination patterns, from what is thought to represent the dilute low concentration and [...]