Preprints
Filtering by Subject: Stratigraphy
A PCA-based framework for determining remotely-sensed geological surface orientations and their statistical quality
Published: 2018-11-07
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Planetary Geology, Planetary Sciences, Planetary Sedimentology, Statistical Methodology, Statistics and Probability, Stratigraphy, Tectonics and Structure
The orientations of planar rock layers are fundamental to our understanding of structural geology and stratigraphy. Remote-sensing platforms including satellites, unmanned aerial vehicles (UAVs), and LIDAR scanners are increasingly used to build three-dimensional models of structural features on Earth and other planets. Remotely-gathered orientation measurements are straightforward to calculate [...]
Growth folds above propagating normal faults
Published: 2018-11-07
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
Growth folds above the upper tips of normal faults are ubiquitous in extensional settings, especially during the early phases of extension and in salt-rich basins. As slip accumulates on the underlying normal fault, the geometry and size of the fold changes. These changes reflect the dip, throw, displacement and propagation rate of the underlying normal fault, as well as the thickness and [...]
Preservation of autogenic processes and allogenic forcings within set-scale aeolian architecture I: numerical experiments
Published: 2018-10-31
Subjects: Earth Sciences, Physical Sciences and Mathematics, Stratigraphy
A reduced complexity aeolian dune stratification model is developed and applied to explore the role of dune morphodynamics in the creation of synthetic sections of aeolian stratigraphy originating from three sets of environmental forcing: 1) steady wind transport capacity, 2) steady bed aggradation and variable wind transport capacity, and 3) steady wind transport capacity and bed aggradation. In [...]
Flow-Substrate Interactions in Aggrading and Degrading Submarine Channels
Published: 2018-10-25
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geology, Geomorphology, Other Civil and Environmental Engineering, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Connecting real time measurements of current-bed interactions to the temporal evolution of submarine channels can be extremely challenging in natural settings. We present a suite of physical experiments that offer insight into the spectrum of interactions between turbidity currents and their channels, from (i) detachment-limited erosion to (ii) transport-limited erosion to (iii) pure deposition. [...]
The deposition and alteration history of the northeast Syrtis Major layered sulfates
Published: 2018-10-16
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Ancient stratigraphy on Isidis Basins western margin records the history of water on early Mars. Noachian units are overlain by layered, basaltic-composition sedimentary rocks that are enriched in polyhydrated sulfates and capped by more resistant units. The layered sulfates – uniquely exposed at northeast Syrtis Major – comprise a sedimentary sequence up to 600-m thick that has undergone a [...]
Vulnerability of Louisiana’s coastal wetlands to present-day rates of relative sea-level rise
Published: 2018-10-01
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Monitoring, Environmental Sciences, Geology, Geomorphology, Hydrology, Natural Resources Management and Policy, Physical Sciences and Mathematics, Risk Analysis, Sedimentology, Soil Science, Stratigraphy, Sustainability
Coastal Louisiana has lost about 5,000km2 of wetlands over the past century and concern exists whether remaining wetlands will persist while facing some of the world’s highest rates of relative sea-level rise (RSLR). Here we analyse an unprecedented data set derived from 274 rod surface-elevation table-marker horizon stations, to determine present-day surface-elevation change, vertical accretion [...]
Quantifying natural delta variability using a multiple-point geostatistics prior uncertainty model
Published: 2018-10-01
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: 2018-09-30
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 [...]
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 bar preservation to constrain reworking in channel-dominated fluvial stratigraphy
Published: 2018-08-17
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 [...]
Ocean Drilling Perspectives on Meteorite Impacts
Published: 2018-08-08
Subjects: Earth Sciences, Geophysics and Seismology, Oceanography and Atmospheric Sciences and Meteorology, Paleobiology, Paleontology, Physical Sciences and Mathematics, Planetary Geomorphology, Planetary Geophysics and Seismology, Planetary Sciences, Stratigraphy
Extraterrestrial impacts are a ubiquitous process in the solar system, reshaping the surface of rocky bodies of all sizes. On early Earth, impact structures may have been a nursery for the evolution of life. More recently, a large meteorite impact caused the end-Cretaceous mass extinction, causing the extinction of 75% of species known from the fossil, including non-avian dinosaurs, and clearing [...]