Preprints
Filtering by Subject: Geology
Anatomy of exhumed river-channel belts: Bedform- to belt-scale kinematics of the Ruby Ranch Member, Cretaceous Cedar Mountain Formation, Utah, USA
Published: 2019-08-29
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Many published interpretations of ancient fluvial systems have relied on observations of extensive outcrops of thick successions. This paper, in contrast, demonstrates that a regional understanding of paleoriver kinematics, depositional setting, and sedimentation rates can be interpreted from local sedimentological measurements of bedform and barform strata. Dune and bar strata, channel planform [...]
Fracture Mechanical Properties of Damaged and Hydrothermally Altered Rocks, Dixie Valley - Stillwater Fault Zone, Nevada, USA
Published: 2019-08-28
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
An edited version of this paper was published by AGU. Copyright (2019) American Geophysical Union. Callahan, O. A., Eichhubl, P., Olson, J. E., & Davatzes, N. C. (2019). Fracture Mechanical Properties of Damaged and Hydrothermally Altered Rocks, Dixie Valley‐Stillwater Fault Zone, Nevada, USA. Journal of Geophysical Research: Solid Earth, 124(4), 4069-4090. [...]
Collapse of Eurasian ice sheets 14,600 years ago was a major source of global Meltwater Pulse 1a
Published: 2019-08-21
Subjects: Climate, Earth Sciences, Environmental Sciences, Geology, Glaciology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Rapid sea-level rise caused by the collapse of large ice sheets is a global threat to human societies. In the last deglacial period, the rate of global sea-level rise peaked at more than 4 cm/yr during Meltwater Pulse 1a, which coincided with the abrupt Bølling warming event 14,650 yr ago. However, the sources of the meltwater have proven elusive, and the contribution from Eurasian ice sheets has [...]
Review paper: The 2nd June 1979 Mw 6.1 Cadoux surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 2nd June 1979 moment magnitude (Mw) 6.1 Cadoux earthquake caused a complex, multi-fault surface rupture consisting of six mapped scarps: (from south to north) the 8 km long west dipping Robb scarp, 3 km long south dipping Cumming scarp, the Lone Tree, Carter and Tank scarps (which together define an east-dipping arcuate rupture) and the 2.5 km long southwest-dipping Kalajzic scarp. Surface [...]
Review paper: The 10th March 1970 Mw 5.0 Calingiri surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 10th March 1970 moment magnitude (Mw) 5.0 Calingiri earthquake surface rupture is 3.3 km long with a maximum vertical displacement of 0.4 m. The fault as defined by surface measurements is a shallow-dipping reverse fault (~ 20° east) with a probable shallow hypocentre (< 1 km). This is consistent with published hypocentral depths, though large uncertainties exist within the seismological [...]
Review paper: The 30th March 1986 Mw 5.7 Marryat Creek surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 30th March 1986 Mw 5.7 Marryat Creek earthquake produced a highly arcuate 13 km long surface rupture with maximum vertical displacement of 0.9 m. Sinistral displacement on the NE-SW limb, dextral displacement on the NNE-SSW limb, and maximum vertical displacement in the central apex of rupture supports SW over NE movement of a hanging-wall block. Epicentre locations are poorly constrained and [...]
Review paper: The 14th October 1968 Mw 6.6 Meckering surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 14th October 1968 MW 6.6 Meckering earthquake surface rupture is comprised of a main 37 km long concave Meckering scarp (with a 1.5 km wide dextral step-over along the Burges en-echelon rupture complex) and a minor 9 km long rupture on the Meckering scarp foot-wall (the Splinter scarp, also with a 1.5 km dextral step-over). We recommend a total surface rupture length of 44.4 km for [...]
Review paper: The 20th May 2016 Mw 6.1 Petermann surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 20th May 2016 Mw 6.1 Petermann earthquake produced a 21 km long surface rupture with a maximum vertical offset of 0.9 m. Geological and geophysical data provide strong evidence that rupture occurred along a mylonite foliation plane with an orientation defined by deformation from the nearby Woodroffe Thrust, a major Neoproterozoic terrane suture. The most geologically and seismologically [...]
Review paper: The 23rd March 2012 Mw 5.2 Pukatja surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 23rd March 2012 Mw 5.2 Pukatja earthquake produced an arcuate surface rupture 1.6 km long with a maximum vertical offset of 0.48 m. We reclassify its length to 1 km based on application of orientation and kinematic criteria used previously to measure other historic Australian surface ruptures. Epicentres are poorly constrained and inaccurate, located up to 17 km from the surface rupture with [...]
Grain-Size and Discharge Controls on Submarine-Fan Depositional Patterns From Forward Stratigraphic Models
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Submarine fans are important components of continental margins; they contain a stratigraphic record of environmental changes and host large accumulations of oil and gas. The grain size and volume of sediment supply to fans is thought to control the heterogeneity of deep-water deposits; predicting spatial variability of sandy and muddy deposits is an important applied challenge in the [...]
Progradational Slope Architecture and Sediment Partitioning in the Outcropping Mixed Siliciclastic-Carbonate Bone Spring Formation, Permian Basin, west Texas
Published: 2019-08-14
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Sediment transport and partitioning are important for understanding slope-building processes in mixed carbonate-siliciclastic sediment routing systems. The Permian-aged Bone Spring Formation, Delaware Basin, west Texas is a mixed carbonate-siliciclastic system that has been extensively studied in its basinal extent, but poorly constrained at its proximal, upper slope segment. In this study, we [...]
Scale matters: The influence of structural inheritance on fracture patterns
Published: 2019-08-12
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Fracture systems are often geometrically invariant across a range of scales, but the impact of structural inheritance on this relationship is poorly understood. This paper shows how fracture orientations in sedimentary rocks vary at different scales when influenced by pre-rift basement structures. We use high-resolution unmanned aerial vehicle (UAV) orthophotos to map folds and fractures in the [...]
Mass-transport complexes (MTCs) document minibasin subsidence patterns and diapir evolution in the northern Gulf of Mexico
Published: 2019-08-08
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Social and Behavioral Sciences
Mass-transport complexes (MTCs) dominate many salt-influenced sedimentary basins. Commonly in such settings, halokinesis is invoked as the primarily trigger for MTC emplacement. Despite being very well-imaged in seismic reflection data, we know little of how MTCs vary in terms of their sedimentological character, which may relate to their provenance, or their triggers. We use high-quality 3D [...]
Deep-water reservoir distribution on a salt-influenced slope, Santos Basin, offshore Brazil
Published: 2019-08-08
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Studies of near-seabed datasets show that salt tectonics controls the distribution and architecture of deep-water reservoirs in many salt-influenced basins. It is typically difficult, however, to study the distribution and stratigraphic evolution of depositional systems preserved at deeper, economically significant depths, reflecting poor seismic imaging of steeply dipping strata flanking [...]
A mechanistic erosion model for cosmogenic nuclide inheritance in fluvial single-clast exposure ages
Published: 2019-08-06
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Statistics and Probability, Tectonics and Structure
Terrestrial cosmogenic nuclides (TCNs), produced by the bombardment of Earth’s surface by cosmic rays, are widely used for age-dating and pacing surface processes. Sediments carry an inherited TCN concentration, useful for quantifying erosion and transport rates, but that must be subtracted when age-dating sedimentary landforms, such as alluvial fans. Here we present a mechanistic model of [...]