Preprints
Filtering by Subject: Tectonics and Structure
Bridging Spatiotemporal Scales of Normal Fault Growth During Continental Extension Using High-Resolution 3D Numerical Models
Published: 2021-04-21
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Continental extension is accommodated by the development of kilometre-scale normal faults, which grow during metre-scale slip events that occur over millions of years. However, reconstructing the entire lifespan of a fault remains challenging due to a lack of observational data with spatiotemporal scales that span the early stage (<10^6 yrs) of fault growth. Using 3D numerical simulations of [...]
CRUSTAL ACCRETION AND CHAIN BUILDING OF AN INHERITED PASSIVE MARGIN: INSIGHTS FROM THE WESTERN SOUTHERN ALPS
Published: 2021-04-20
Subjects: Tectonics and Structure
Recently, the influence of lithospheric extension on later orogeny has gained increasing interest. We make use of own geological mapping, interpretations of seismic reflection profiles and deep geophysical data to build an area-balanced cross-section across a key area of the Western Southern Alps and to model a series of structural restorations from the end of Mesozoic rifting to present-day. The [...]
The 2019-2020 Southwest Puerto Rico earthquake sequence: seismicity and faulting
Published: 2021-04-20
Subjects: Geophysics and Seismology, Tectonics and Structure
The 2019-2020 Southwest Puerto Rico earthquake sequence ruptured multiple faults with several moderate magnitude earthquakes. Here we investigate the seismotectonics of this fault system using high precision hypocenter relocation and inversion of the near-field strong motions of five largest events in the sequence (5.6≤Mw≤6.4) for kinematic rupture models. The Mw6.4 mainshock occurred on an NE [...]
The Mid-Lithospheric Discontinuity caused by channel flow in the cratonic lithosphere
Published: 2021-04-20
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Stable cratons with a thick (> 200 km) and cold lithosphere form rheologically strong plates that move atop a ductile asthenospheric mantle. Various types of seismic observations show the presence of a potentially rheologically weak zone at depths of ca. 80 – 150 km termed the Mid-Lithosphere Discontinuity (MLD). While various mechanisms may explain the MLD, the dynamic processes leading to the [...]
Stress and Strain during Shock Metamorphism
Published: 2021-04-15
Subjects: Geology, Planetary Geology, Planetary Geophysics and Seismology, Tectonics and Structure
Shock metamorphism is the process by which rocks, and the minerals within them, transform during the passage of a shock wave. Shock effects, such as shatter cones, are critical for the identification of impact structures and have commonly been used to infer mechanical and structural information on the cratering process. To make these inferences, the mechanics of shock wave behavior must be [...]
Structure and Stress Field of the Lithosphere between Pamir and Tarim
Published: 2021-04-14
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The Pamir plateau protrudes ~300 km between the Tajik- and Tarim-basin lithosphere of Central Asia. Whether its salient location and shape are caused by forceful indentation of a promontory of Indian mantle lithosphere is debated. We present a new local-seismicity and focal-mechanism catalog, and a P-wave velocity model of the eastern part of the collision system. The data suggest a [...]
Rectangular drainage pattern evolution controlled by pipe cave collapse along clastic dikes, the Dead Sea Basin, Israel
Published: 2021-04-09
Subjects: Geomorphology, Tectonics and Structure
Coulomb Threshold Rate-and-State Model for Fault Reactivation: Application to induced seismicity at Groningen
Published: 2021-04-06
Subjects: Environmental Monitoring, Geophysics and Seismology, Tectonics and Structure
A number of recent modeling studies of induced seismicity have used the rate-and-state friction model of Dieterich (1994) to account for the fact that earthquake nucleation is not instantaneous. Notably, the model assumes a population of seismic sources accelerating towards instability with a distribution of intial slip speeds such that they would produce earthquakes steadily in the absence of [...]
Dilatancy and compaction of a rate-and-state fault in a poroelastic medium: Linearized stability analysis
Published: 2021-04-06
Subjects: Applied Mathematics, Geophysics and Seismology, Tectonics and Structure
Faults in the crust at seismogenic depths are embedded in a fluid-saturated, elastic, porous material. Slip on such faults may induce transient pore pressure changes through dilatancy or compaction of the gouge or host rock. However, the poroelastic nature of the crust and the full coupling of inelastic gouge processes and the host rock have been largely neglected in previous analyses. Here, we [...]
Resolving Northern Alaska Earthquake Sequences Using the Transportable Array and Probabilistic Location Methods
Published: 2021-03-25
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Between 2014 and 2017, almost 200 new seismic stations were installed in Alaska and northwestern Canada as part of the EarthScope USArray Transportable Array. These stations currently provide an unprecedented capability for the detection and location of seismic events in regions with otherwise relatively sparse station coverage. Two interesting earthquake sequences in 2018 and 2019 in the [...]
Low variability runoff inhibits coupling of climate, tectonics, and topography in the Greater Caucasus
Published: 2021-03-23
Subjects: Geomorphology, Tectonics and Structure
Hypothesized feedbacks between climate and tectonics are mediated by the relationship between topography and long-term erosion rates. While many studies show monotonic relationships between channel steepness and erosion rates, the degree of nonlinearity in this relationship varies by landscape. Mechanistically explaining controls on this relationship in natural settings is critical because highly [...]
Mechanical Stratigraphy Controls Normal Fault Growth and Dimensions, Outer Kwanza Basin, Offshore Angola
Published: 2021-03-19
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Mechanical stratigraphy controls the growth patterns and dimensions of relatively small normal faults, yet how its influences the development of much larger structures remains unclear. Here we use 3D seismic reflection data from the Outer Kwanza Basin, offshore Angola to constrain the geometry and kinematics of several normal faults formed in a deep-water clastic succession. The faults are up to [...]
Polygenetic mélange in the retrowedge foredeep of an active arc-continent collision, Coastal Range of eastern Taiwan (accepted manuscript)
Published: 2021-03-17
Subjects: Earth Sciences, Geology, Sedimentology, Stratigraphy, Tectonics and Structure
The Plio-Pleistocene Lichi Mélange in the Coastal Range of eastern Taiwan offers an excellent opportunity to study processes of mélange development at the continent-ocean interface of an active arc-continent collision. This paper presents new results of detailed geologic mapping, lithofacies analysis, magneto-biostratigraphy, paleocurrent, and paleoslope analyses in the southern Coastal Range to [...]
The Sidi Ifni transect across the rifted margin of Morocco (Central Atlantic): Vertical movements constrained by low-temperature thermochronology
Published: 2021-03-17
Subjects: Earth Sciences, Geology, Geomorphology, Paleontology, Sedimentology, Stratigraphy, Tectonics and Structure
The occurrence of km-scale exhumations during syn- and post-rift stages has been documented along Atlantic continental margins, which are also characterised by basins undergoing substantial subsidence. The relationship between the exhuming and subsiding domains is poorly understood. In this study, we reconstruct the evolution of a 50 km long transect across the Moroccan rifted margin from the [...]
An analytical solution for the exhumation of an orogenic wedge and a comparison with thermochronology data
Published: 2021-03-05
Subjects: Geology, Tectonics and Structure
Thermochronology data is key for quantifying the exhumation history and dynamics of mountain belts. Here we present a new analytical solution for the steady-state exhumation of an orogenic wedge that undergoes transport along a basal detachment, uniform internal deformation, basal and frontal accretion. The solution predicts an increase in exhumation towards the interior of the wedge, with the [...]