Preprints
Filtering by Subject: Geology
Controls of basement fabric on rift coupling and development of normal fault geometries: Insights from the Rukwa – North Malawi Rift
Published: 2018-08-19
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The Rukwa Rift and North Malawi Rift Segments (RNMRS) both define a major rift-oblique segment of the East African Rift System (EARS), and although the two young rifts show colinear approaching geometries, they are often regarded as discrete rifts due to the presence of the intervening Mbozi Block uplift located in-between. This problem has been complicated by the dominance of the Rungwe volcanic [...]
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 [...]
Dalangtan Saline Playa in a Hyperarid Region of Tibet Plateua-III: Correlated Multiscale Surface Mineralogy and Geochemistry Survey
Published: 2018-08-15
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
We report the first multiscale, systematic field-based testing of correlations between orbital scale advanced spaceborne thermal emission and reflection radiometer visible near-infrared (VNIR)/shortwave infrared (SWIR) reflectance and thermal infrared relative emissivity and outcrop scale Raman spectroscopy, VNIR reflectance, X-ray diffraction (XRD), and laser-induced breakdown spectroscopy [...]
Quantification of the Bed-scale Architecture of Submarine Depositional Environments and Application to Lobe Deposits of the Point Loma Formation, California
Published: 2018-08-11
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 [...]
Lithologic controls on the form of soil mantled hillslopes
Published: 2018-07-20
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics
Slopes in steady-state soil-mantled landscapes tend to increase downslope in a way that balances local transport capacity with the sediment supplied from progressively larger source areas. Most formulations of sediment transport due to hillslope processes scale transport rate with local slope, which produces convex-up forms that are independent of the properties of the underlying lithologies. In [...]
Tectonic and oceanographic process interactions archived in the Late Cretaceous to Present deep-marine stratigraphy on the Exmouth Plateau, offshore NW Australia
Published: 2018-07-11
Subjects: Earth Sciences, Engineering, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Deep-marine deposits provide a valuable archive of process interactions between sediment gravity flows, pelagic sedimentation, and thermo-haline bottom-currents. Stratigraphic successions can also record plate-scale tectonic processes (e.g. continental breakup and shortening) that impact long-term ocean circulation patterns, including changes in climate and biodiversity. One such setting is the [...]
Coseismic extension recorded within the damage zone of the Vado di Ferruccio Thrust Fault, Central Apennines, Italy
Published: 2018-07-02
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Recent high resolution hypocentral localisation along active fault systems in the Central Apennines illuminates the activation of seismogenic volumes dipping at low angle (<30°) in extensional settings overprinting contractional deformations affecting the continental crust of the Adria microplate. Individuation of the geological structures and of the fault processes associated with these [...]
Cyclic CO2 – H2O injection and residual trapping: implications for CO2 injection efficiency and storage security
Published: 2018-06-28
Subjects: Earth Sciences, Environmental Sciences, Geochemistry, Geology, Oil, Gas, and Energy, Physical Sciences and Mathematics, Sustainability
To meet the Paris Agreement target of limiting global warming to 2ºC or below it is widely accepted that Carbon Capture and Storage (CCS) will have to be deployed at scale. The influence of residual trapping on CO2 well injectivity and its response over time has a major impact on the injection efficiency and storage capacity of CO2 storage sites. For the first time, experiments have been [...]
Micromorphological report of Hof ter Coign
Published: 2018-06-28
Subjects: Agriculture, Earth Sciences, Education, Engineering, Environmental Sciences, Environmental Studies, Geography, Geology, Life Sciences, Physical and Environmental Geography, Physical Sciences and Mathematics, Sedimentology, Social and Behavioral Sciences, Soil Science
Micromorphological report of the Hof ter Coign site (Belgium)
Quantitative analysis of fluvial paleohydraulics and intra-channel belt stratal preservation: lower Wasatch Formation, Utah, USA
Published: 2018-06-22
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
This article uses measurements from five fluvial channel belts of the Paleocene lower Wasatch Formation to quantitatively document the transience or persistence of flow velocities recorded in stratigraphy at the bedset scale. We use facies proportions and sedimentary structures coupled with a paleoflow velocity workflow to calculate the mean flow velocity for each bedset. Flow velocity [...]
Landscape classification with deep neural networks.
Published: 2018-06-18
Subjects: Computer and Systems Architecture, Computer Engineering, Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Geology, Geomorphology, Other Statistics and Probability, Physical Sciences and Mathematics, Statistics and Probability
The application of deep learning, specifically deep convolutional neural networks (DCNNs), to the classification of remotely sensed imagery of natural landscapes has the potential to greatly assist in the analysis and interpretation of geomorphic processes. However, the general usefulness of deep learning applied to conventional photographic imagery at a landscape scale is, at yet, largely [...]