Preprints
Filtering by Subject: Geology
Fingerprinting fluid source in calcite veins: combining LA-ICP-MS U-Pb calcite dating with trace elements and clumped isotope palaeothermometry
Published: 2020-07-15
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Application of geochemical proxies to vein minerals - particularly calcite - can fingerprint the source of fluids controlling various important geological processes from seismicity to geothermal systems. Determining fluid source, e.g. meteoric, marine, magmatic or metamorphic waters, can be challenging when using only trace elements and stable isotopes as different fluids can have overlapping [...]
Neoproterozoic Geochronology and Provenance of the Adelaide Superbasin
Published: 2020-07-15
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
The Adelaide Superbasin (Adelaide Rift Complex, Stuart Shelf, Torrens Hinge Zone, Coombalarnie Platform, and Cambrian Stansbury and Arrowie Basins) is a vast sedimentary basin in southern Australia that initiated due to the break-up of central Rodinia and, evolved into the Australian passive margin on edge of the Pacific Basin. Rocks within it contain evidence for the evolving earth system [...]
Age and geochemistry of the Boucaut Volcanics in the Neoproterozoic Adelaide Rift Complex, South Australia
Published: 2020-07-15
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
The Adelaide Rift Complex in South Australia records the break-up of Rodinia at a time of great climatic and biological evolution. The Boucaut Volcanics within the Neoproterozoic Adelaide Rift Complex of the Adelaide Superbasin lie at the base of the Burra Group, marking the boundary between the Burra Group and underlying Callanna Group. Despite their significance as one of the few volcanic units [...]
What Controls Salt‐Detached Contraction in the Translational Domain of the Outer Kwanza Basin, Offshore Angola?
Published: 2020-07-13
Subjects: Earth Sciences, Engineering, Geology, Life Sciences, Physical Sciences and Mathematics, Tectonics and Structure
It is now well‐established that base‐salt relief drives complex deformation patterns in the mid‐slope domain of salt‐bearing passive margins, in a location classically thought to be dominated by simple horizontal translation. However, due to a lack of detailed studies drawing on high‐quality, 3D seismic reflection data, our understanding of how base‐salt relief controls four‐dimensional patterns [...]
GANSim: Conditional Facies Simulation Using an Improved Progressive Growing of Generative Adversarial Networks (GANs)
Published: 2020-07-06
Subjects: Artificial Intelligence and Robotics, Computer Sciences, Earth Sciences, Geology, Hydrology, Mathematics, Physical Sciences and Mathematics, Sedimentology, Statistical Models, Statistics and Probability
Conditional facies modeling combines geological spatial patterns with different types of observed data, to build earth models for predictions of subsurface resources. Recently, researchers have used generative adversarial networks (GANs) for conditional facies modeling, where an unconditional GAN is first trained to learn the geological patterns using the original GANs loss function, then [...]
Dislocation interactions in olivine control postseismic creep of the upper mantle
Published: 2020-06-30
Subjects: Condensed Matter Physics, Earth Sciences, Geology, Mineral Physics, Physical Sciences and Mathematics, Physics, Tectonics and Structure
Changes in stress applied to mantle rocks, such as those imposed by earthquakes, induce a period of evolution in viscosity and microstructure. This transient creep is often modelled based on stress transfer among slip systems due to grain interactions. However, recent experiments have demonstrated that the intragranular accumulation of stresses among dislocations is the dominant cause of strain [...]
Fully Automated Carbonate Petrography Using Deep Convolutional Neural Networks
Published: 2020-06-23
Subjects: Artificial Intelligence and Robotics, Computer Sciences, Earth Sciences, Geology, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology
Carbonate rocks are important archives of past ocean conditions as well as hosts of economic resources such as hydrocarbons, water, and minerals. Geologists typically perform compositional analysis of grain, matrix, cement and pore types in order to interpret depositional environments, diagenetic modification, and reservoir quality of carbonate strata. Such information can be obtained primarily [...]
Rates of olivine grain growth during dynamic recrystallization and post-deformation annealing
Published: 2020-06-23
Subjects: Earth Sciences, Geology, Mineral Physics, Physical Sciences and Mathematics, Tectonics and Structure
We performed deformation and grain growth experiments on natural olivine aggregates with moderate olivine water contents (COH = 600±300 ppm H/Si) at 1000-1200°C and a confining pressure of 1400±100 MPa. Our experiments differ from published grain growth studies in that most were: 1) conducted on natural olivine cores rather than hot-pressed aggregates, and 2) dynamically recrystallized prior to [...]
Geological Facies Modeling Based on Progressive Growing of Generative Adversarial Networks (GANs)
Published: 2020-06-22
Subjects: Artificial Intelligence and Robotics, Computer Sciences, Earth Sciences, Geology, Geophysics and Seismology, Hydrology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Geological facies modeling has long been studied to predict subsurface resources. In recent years, generative adversarial networks (GANs) have been used as a new method for geological facies modeling with surprisingly good results. However, in conventional GANs, all layers are trained concurrently, and the scales of the geological features are not considered. In this study, we propose to train [...]
Across-strike asymmetry of the Andes orogen linked to the age and geometry of the Nazca plate
Published: 2020-06-18
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
The spine of Andes – the trace of the highest mountain topography – weaves back and forth, in places near the coastline, in others farther inland. Its position is thought to be partially influenced by the asymmetric distribution of rainfall causing the migration of the topographic divide (i.e. mountain peaks) in favor of the more erosive (wetter) side and consuming the less erosive (drier) side. [...]
Syn-depositional Mesozoic siliciclastic pathways on the Moroccan Atlantic margin linked to evaporite mobilisation
Published: 2020-06-17
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Evaporite mobilisation in evaporite-cored anticlines leads to topographic growth that can alter sedimentary routing in shallow marine environments. This paper analyses two evaporite-cored anticlines perpendicular to the NW Africa coast to understand how their tectonic evolution influenced sediment pathways during the Early to Middle Jurassic and Early Cretaceous exhumation of the Mesozoic margin [...]
Notes on statistical age dispersion in fission-track datasets: the chi-square test, annealing variability, and analytical considerations
Published: 2020-06-13
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Notes on fission track statistics, the chi-square test, annealing (i.e. fission track age) variability, and analytical bias aimed at a general Earth scientist audience and for users of fission track data
Ancient siderites reveal hot and humid super-greenhouse climate
Published: 2020-06-10
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Earth’s climate is warming as the rise in atmospheric CO2 (pCO2) contributes to increased radiative forcing. State-of-the-art models calculate a wide range in Earth’s climate sensitivities due to increasing pCO2, and, in particular, the mechanisms responsible for amplification of high latitude temperatures remain highly debated. The geological record provides a means to evaluate the consequences [...]
Strain migration during multiphase extension, Stord Basin, northern North Sea rift
Published: 2020-06-07
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
In multirifted regions, rift-related strain varies along and across the basin during and between each extensional event, and the location of maximum extension often differs between rift phases. Despite having a general understanding of multiphase rift kinematics, it remains unclear why some parts of the rift are abandoned, with strain accumulating in previously less deformed areas, and how [...]
Architecture and controls of thick, intensely bioturbated, storm-influenced shallow-marine successions: an example from the Jurassic Neuquén Basin (Argentina)
Published: 2020-06-06
Subjects: Earth Sciences, Geology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Thick (>100 m-thick), highly bioturbated storm-influenced shallow-marine deposits are not frequent in the stratigraphic record, but they tend to be unusually common in aggradational to retrogradational successions. Individual storm-event beds have typically low preservation in these successions, yet depositional settings are characterized on the basis of storms processes. We present a [...]