Preprints
Filtering by Subject: Earth Sciences
The Byers Basin: Jurassic-Cretaceous tectonic and depositional evolution of the forearc deposits of the South Shetland Islands and its implications for the northern Antarctic Peninsula
Published: 2019-08-01
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
This paper addresses the Jurassic–Cretaceous stratigraphic evolution of fore-arc deposits exposed along the west coast of the northern Antarctic Peninsula. In the South Shetland Islands, Upper Jurassic deep-marine sediments are uncomformably overlain by a Lower Cretaceous volcaniclastic sequence that crops out on Livingston, Snow and Low islands. U-Pb zircon ages are presented for the upper [...]
The Gondwanan margin in West Antarctica: insights from Late Triassic magmatism of the Antarctic Peninsula
Published: 2019-08-01
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Triassic orthogneisses of the Antarctic Peninsula provide evidence for the Palaeozoic and Mesozoic geological evolution of southern Gondwana within Pangaea. These rocks are sporadically exposed in southeastern Graham Land and northwestern Palmer Land, although reliable geochronological, geochemical and isotopic data are sparse. We combine new geochronological (LA-ICP-MS zircon U-Pb), geochemical, [...]
Offsetting Carbon Capture and Storage costs with methane and geothermal energy production through reuse of a depleted hydrocarbon field coupled with a saline aquifer
Published: 2019-07-26
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Co-production of methane and geothermal energy from produced subsurface brines with onsite power generation and carbon capture has been proposed as a technically feasible means to reduce the costs of offshore carbon storage sites. In such a facility, methane is degassed from produced brine, this brine is then cooled allowing the extraction of heat and then CO2 is dissolved into it for reinjection [...]
Basal melting over Subglacial Lake Ellsworth and it catchment: insights from englacial layering
Published: 2019-07-25
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Hydrology, Physical Sciences and Mathematics
Deep-water ‘stable’ subglacial lakes likely contain microbial life adapted in isolation to extreme environmental conditions. How water is supplied into a subglacial lake, and how water outflows, is important for understanding these conditions. Isochronal radio-echo layers have been used to infer where melting occurs above Lake Vostok and Lake Concordia in East Antarctica but have not been used [...]
Comment on Evaristo & McDonnell, Global analysis of streamflow response to forest management
Published: 2019-07-25
Subjects: Earth Sciences, Environmental Sciences, Forest Management, Forest Sciences, Hydrology, Life Sciences, Physical Sciences and Mathematics, Water Resource Management
Forests play a key role in the water cycle, so both planting and removing forests can affect streamflow. In a recent Nature article1, Evaristo and McDonnell used a gradient-boosted-tree model to conclude that streamflow response to forest removal is predominantly controlled by the potential water storage in the landscape, and that removing the worlds forests would contribute an additional 34,098 [...]
Geostatistical characterisation of internal structure of mass-transport deposits from seismic reflection images and borehole logs
Published: 2019-07-25
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Seismic reflection images of mass-transport deposits often show apparently chaotic, disorded or low-reflectivity internal seismic facies. The lack of laterally coherent reflections can prevent horizon-based interpretation of internal structure. This study instead inverts for geostatistical parameters which characterise the internal heterogeneity of mass-transport deposits from depth-domain [...]
Using T. C. Chamberlins Approach for Determining the forces that Move the Earths Tectonic Plates
Published: 2019-07-24
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The approach in this paper stems primarily from the application of principles of the philosophy of science to determine if current ideas on the forces of plate tectonics are plausible. The philosophic principles (1) Bacons scientific method using T. C. Chamberlins idea of examining multiple hypothesis; and (2) the characteristics of a good theory. it is shown that the driving forces of plate [...]
Giant meandering channel systems controlled by sediment supply to the deep-water Campos basin
Published: 2019-07-24
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Stratigraphy
Large meandering submarine-channel systems are important conduits for mass transfer to continental margins; wider and deeper channels, with larger meanders, reflect larger sediment discharge. Some large meandering channel systems are known to receive voluminous sediment from the largest rivers in the world, such as the Ganges-Brahmaputra, Amazon, Indus, Mississippi, and Zaire (Congo); however, [...]
Considering fault interaction in estimates of absolute stress along faults in the San Gorgonio Pass region, southern California
Published: 2019-07-23
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Present-day shear tractions along faults of the San Gorgonio Pass region can be estimated from stressing rates provided by three-dimensional forward crustal deformation models. Modeled dextral shear stressing rates on the San Andreas and San Jacinto faults differ from rates resolved from the regional loading due to fault interaction. In particular, fault patches with similar orientations and [...]
Investigating the role of faults in fluid migration and gas hydrate formation along the southern Hikurangi Margin, New Zealand
Published: 2019-07-23
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The Hikurangi Margin off the east coast of the North Island (Te Ika-a-Māui) is a tectonically active subduction zone and the location of New Zealand’s largest gas hydrate province. Faults are internally complex volumetric zones that may play a significant role in the migration of fluids beneath the seafloor. The combined processes of deformation and fluid migration result in the formation of [...]
Are we in the right path in using early warning systems?
Published: 2019-07-22
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
This article focusses on the recent tsunami in Indonesia, and the factors led to a large number of fatalities. We also discussed the failure of early warning systems, steps, methods and technologies, in general, to improve the early warning systems in the future to mitigate the loss of lives and property during these impending disasters. This article is timely as Indonesia has seen one of the [...]
Base-Salt Relief Controls Salt-Related Deformation in the Outer Kwanza Basin, offshore Angola
Published: 2019-07-22
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
We use a 3D seismic dataset from Offshore Angola to document the salt-influenced translation and evolution of structures on the margin.
What is Trishear?
Published: 2019-07-21
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The kinematics of fault-propagation folds, formed above the tips of upward propagating normal faults, is typically inferred from numerical and physical models. Trishear is a forward kinematic model in which deformation occurs in a triangular zone in front of the propagating fault tip, with the geometry of this zone, and the geometry and growth of the resulting fold, related to several parameters [...]
Contrasting TiO2 compositions in Early Cenozoic mafic sills of the Faroe Islands: an example of basalt formation from distinct melting regimes
Published: 2019-07-21
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Abstract: The Paleocene lava succession of the Faroe Islands Basalt Group (FIBG), which is a part of the North Atlantic Igneous Province (NAIP), is intruded by numerous basaltic sills. These can be grouped into three main categories according to their geochemical characteristics: A low-TiO2 sill category (TiO2 = 0.7-0.9), a relatively high-TiO2 sill category (TiO2 = 1.95-2.6) and an [...]
Interaction of Sea-Level Pulses with Periodically Retreating Barrier Islands
Published: 2019-07-19
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics
Barrier deposits preserved on continental shelf seabeds provide a record of the paleocoastal environment from the last glacial maximum through the Holocene. The formation of these offshore deposits is often attributed to intermittent periods of rapidly rising sea levels, especially glacial meltwater pulses, which are expected to lead to partial or complete drowning—overstepping—of migrating [...]