Preprints
Filtering by Subject: Geology
Application of multivariate statistical methods to hydrogeological property parameterisation from geotechnical and geophysical data
Published: 2019-04-26
Subjects: Earth Sciences, Environmental Sciences, Geology, Hydrology, Other Earth Sciences, Physical Sciences and Mathematics, Water Resource Management
Hydrogeological data sets are often relatively sparse compared to the scale of investigation, resulting in degrees of uncertainty which, although constrained, may be considered as not acceptable for achieving the desired precision in numerical modelling. The potential use of multivariate statistical methods in identifying correlations between geotechnical properties of the rock mass and hydraulic [...]
High-angular resolution electron backscatter diffraction as a new tool for mapping lattice distortion in geological minerals
Published: 2019-04-19
Subjects: Earth Sciences, Geology, Mineral Physics, Physical Sciences and Mathematics
Analysis of distortions of the crystal lattice within individual mineral grains is central to the investigation of microscale processes that control and record tectonic events. These distortions are generally combinations of lattice rotations and elastic strains, but a lack of suitable observational techniques has prevented these components being mapped simultaneously and routinely in earth [...]
The stratigraphic evolution of onlap in siliciclastic deep-water systems: Autogenic modulation of allogenic signals
Published: 2019-04-10
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Seafloor topography affects the sediment gravity flows that interact with it. Understanding this interaction is critical for accurate predictions of sediment distribution, paleogeography, and structural reconstructions of deep-water basins. The effects of seafloor topography can be seen from the bed scale, through facies transitions toward intra-basinal slopes, to the basin scale, where onlap [...]
Characterising strong force networks produced during granular shear using percolation methods: Revealing the bridge between local grain scale processes and macroscopic sliding
Published: 2019-04-08
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics, Physics, Tectonics and Structure
Faults, landslides and subglacial till often contain accumulations of granular debris. Their macroscopic motion is at least to some extent determined by the processes operating in this sheared granular material. A valid question in these environments is how the local behaviour at the individual granular contacts actually sums up to influence macroscopic sliding. Laboratory experiments and [...]
Determining cooling rates from mica 40Ar/39Ar thermochronology data: effect of cooling path shape
Published: 2019-04-02
Subjects: Earth Sciences, Geochemistry, Geology, Other Earth Sciences, Physical Sciences and Mathematics
Tectonic models are commonly underpinned by metamorphic cooling rates derived from diffusive-loss thermochronology data. Such cooling ages are usually linked to temperature via Dodson’s 1973 closure temperature (TC) formulation, which specifies a 1/time-shaped cooling path. Geologists, however, commonly discuss cooling rates as a linear temperature/time shape. We present the results of a series [...]
The Cyclic Preservation of Clastic and Evaporitic Sabkha Sediments: Insights from the Cedar Mesa Sandstone Formation of the Cutler Group, Utah, USA
Published: 2019-04-01
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
The strata of arid continental basins commonly comprise evaporitic sediments deposited in sabkha settings combined with clastic sediments derived from aeolian, fluvial and/or lacustrine settings. The sedimentary character of these mixed successions and the degree to which evaporitic strata influence their composition, both contribute towards the economic potential of the evaporitic and the [...]
A macroscale hydrogeological numerical model of the Suio hydrothermal system (central Italy)
Published: 2019-04-01
Subjects: Earth Sciences, Environmental Sciences, Geochemistry, Geology, Natural Resources and Conservation, Physical Sciences and Mathematics, Water Resource Management
The complex behaviour of the Suio hydrothermal system (central Italy) and its potential exploitation as a renewable energy source are still unclear. To quantitatively evaluate the geothermal resource, the Suio hydrothermal system has been investigated with a hydrogeological numerical model that couples fluid flow, thermal convection, and transport of diluted species inside a hybrid [...]
Audit of Petroleum Exploration Wells in the UK Rockall Basin: 1980-2006
Published: 2019-04-01
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
The UK Rockall Basin is one of the most underexplored areas of the UK Continental Shelf (UKCS) with only 12 exploration wells drilled since 1980, in a basin area that is equal in size to the entire North Sea hydrocarbon province (NNS, CNS & SNS). With only one discovery, made in 2000 (Benbecula South 154/1-1 Gas discovery), the general view of the basin from an exploration viewpoint has not [...]
Comment on “Long-term strain oscillations related to the hydrogeological interaction between aquifers in intra-mountain basins: A case study from Apennines chain (Italy)” by Devoti, Riguzzi, Cinti and Ventura
Published: 2019-03-29
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
The paper by Devoti et al. (2018) analyses the GPS time series from seventeen stations located inside and in the neighboring of the L’Aquila intermountain basin. The authors suggest that the observed movements are due to regional hydrological processes likely associated with multi-annual climatic variations. The analysis performed by Devoti et al. (2018) contains an issue in the GPS-InSar [...]
3-D seismic images of an extensive igneous sill in the lower crust
Published: 2019-03-29
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
When continents rift, magmatism can produce large volumes of melt that migrate upwards from deep below the Earth’s surface. To understand how magmatism impacts rifting, it is critical to understand how much melt is generated and how it transits the crust. Estimating melt volumes and pathways is difficult, however, particularly in the lower crust where the resolution of geophysical techniques is [...]
Direct observations of the coupling between quartz dissolution and Mg-silicate formation
Published: 2019-03-20
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Although quartz is a stable mineral at Earth surface conditions, field samples have shown its rapid dissolution in combination with the precipitation of Mg-silicate phases. Atomic force microscopy (AFM) experiments were performed to investigate the dissolution of quartz and the precipitation of secondary phases in high-pH, Mg-rich solutions both in-situ and ex-situ. Experiments were conducted at [...]
Formation of magnesium silicate hydrate cement in nature
Published: 2019-03-19
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
Tillite lithified by magnesium silicate hydrate (M-S-H) cement has been formed at the surface of the Feragen Ultramafic Body in SE Norway. Serpentinization of olivine-rich rocks led to formation of brucite that dissolves during weathering to form a high pH (>9) Mg-rich fluid. This fluid dissolves quartz deposited by glaciers during the Weichselian glaciation. Subsequent evaporation leads to [...]
Obstructed Minibasins on a Salt-Detached Slope: An Example from above the Sigsbee Canopy, Northern Gulf of Mexico
Published: 2019-03-19
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Salt-detached gravity-gliding/spreading systems having a rugose base-of-salt display complex strain patterns. However, little was previously known about how welding of supra-salt minibasins to the sub-salt may influence both the downslope translation of minibasins on salt-detached slopes and the regional pattern of supra-salt strain. Using a regional 3D seismic reflection data set, we examine a [...]
Poroelastic effects destabilize mildly rate-strengthening friction to generate stable slow slip pulses
Published: 2019-03-19
Subjects: Applied Mechanics, Earth Sciences, Engineering, Geology, Geophysics and Seismology, Mechanical Engineering, Physical Sciences and Mathematics, Physics, Statistical, Nonlinear, and Soft Matter Physics, Tribology
Slow slip events on tectonic faults, sliding instabilities that never accelerate to inertially limited ruptures or earthquakes, are one of the most enigmatic phenomena in frictional sliding. While observations of slow slip events continue to mount, a plausible mechanism that permits instability while simultaneously limiting slip speed remains elusive. Rate-and-state friction has been successful [...]
Equifinality and preservation potential of complex eskers
Published: 2019-03-15
Subjects: Earth Sciences, Geology, Geomorphology, Glaciology, Hydrology, Physical Sciences and Mathematics
Eskers are useful for reconstructing meltwater drainage systems of glaciers and ice sheets. However, our process understanding of eskers suffers from a disconnect between sporadic detailed morpho-sedimentary investigations of abundant large-scale ancient esker systems, and a small number of modern analogues where esker formation has been observed. This paper presents the results of detailed field [...]