Preprints
Filtering by Subject: Tectonics and Structure
The influence of a sub-lithospheric layer width on the partitioning of the induced mantle flow, surface motions and subduction dynamics
Published: 2024-04-17
Subjects: Geophysics and Seismology, Other Earth Sciences, Planetary Geology, Tectonics and Structure
The partitioning of the three-dimensional mantle flow into toroidal and poloidal components is a diagnostic element to characterise tectonics regimes, with both fields being substantially active and representative of the contemporary mode of mantle convection. The toroidal:poloidal ratio (T/P) affects several aspects of mantle circulation, including the sinking of the subducting lithosphere into [...]
Digitising sandbox experiments using open-source Structure-from-Motion/photogrammetry/Digital Image Correlation package MicMac
Published: 2024-04-15
Subjects: Geology, Geophysics and Seismology, Tectonics and Structure, Volcanology
Structure-from-Motion and photogrammetry have been implemented in sandbox models to monitor deformation of their surface. Various software packages are available, either open-source of commercial. Some commercial packages are intuitive press-button equipment; these can be very practical to use, but they can be very expensive and unaffordable for most academic laboratories. Another option is [...]
Evolution and architecture of an exhumed ocean-facing coarse-grained submarine canyon fill, Baja California, Mexico
Published: 2024-04-15
Subjects: Earth Sciences, Geology, Sedimentology, Stratigraphy, Tectonics and Structure
Present day submarine canyons are active conduits for large volumes of sediment, carbon, and pollutants from continents to oceans. However, the evolution of submarine canyons over geological timescales remains poorly understood due to their erosional nature and low preservation potential. The Late Cretaceous Punta Baja Formation represents a well-preserved submarine canyon-fill on a [...]
Brittle origin of off-fault fractures during the 2019 Ridgecrest earthquake sequence
Published: 2024-03-15
Subjects: Earth Sciences, Geophysics and Seismology, Tectonics and Structure
According to the classical Mohr-Coulomb-Anderson theory, faults form at an angle from the largest regional compressive stress that is approximately 30° for most rocks. However, real settings are more complex and faults often present orientations inconsistent with the angles predicted by the classical theory applied to the present-day regional stress field. The Ridgecrest region hosts a young [...]
The role of salt diapirism in controlling the sedimentology and distribution of deep-water deposits, Pierce Field, East Central Graben, North Sea
Published: 2024-03-04
Subjects: Earth Sciences, Geology, Other Earth Sciences, Sedimentology, Tectonics and Structure
Passively rising diapirs control flank deformation (i.e., within 1 km of the salt-sediment interface) and resultant stratigraphic architecture of syn-kinematic units. Growth strata associated with deformation at the flanks of passive diapirs are known as halokinetic sequences. Very few studies have conducted an integrated analysis of composite halokinetic sequences, CHS (stacked halokinetic [...]
Reconstructing Quaternary sea-level through bayesian inversion of staircase coastal landscapes
Published: 2024-02-10
Subjects: Earth Sciences, Geology, Geomorphology, Tectonics and Structure
Quantifying Quaternary sea-level changes and hydroclimatic conditions is an important challenge given their intricate relation with paleo-climate, ice-sheets and geodynamics. The world’s coastlines provide an enormous geomorphologic archive, from which forward landscape evolution modelling studies have shown their potential to unravel paleo sea-levels, albeit at the cost of assumptions to the [...]
Quaternary and Pliocene sea-level changes at Camarones, central Patagonia, Argentina
Published: 2024-01-20
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Tectonics and Structure
Geological indicators of past relative sea level changes are fundamental to reconstruct the extent of former ice sheet during past interglacials, which are considered analogs for future climate conditions. Four interglacials, dating from Holocene to Pliocene, have left sea-level imprints in the proximity of the coastal town of Camarones in Central Patagonia, Argentina. Sea-level index points were [...]
Transient aseismic vertical deformation across the Pisia-Skinos normal fault (Gulf of Corinth, Greece)
Published: 2024-01-18
Subjects: Earth Sciences, Geophysics and Seismology, Tectonics and Structure
Geodetically-derived deformation rates are sometimes used to infer seismic hazard, implicitly assuming that short-term (annual-decadal) deformation is representative of longer-term deformation. This is despite geological observations indicating that deformation/slip rates are variable over a range of timescales. Using geodetic data from 2016-2021, we observe an up to 7-fold increase in vertical [...]
Dynamic evolution of competing same-dip double subduction: New perspectives of the Neo-Tethyan plate tectonics
Published: 2024-01-15
Subjects: Earth Sciences, Geophysics and Seismology, Tectonics and Structure
Same-dip double-subduction (SDDS) systems are widely reported from present as well as past complex convergent plate tectonic configurations. However, the dynamics of their evolution is poorly understood, which is crucial to conceptualize anomalous subducting slab kinematics and associated observed geological phenomena, such as irregular trench migration rates, high convergence velocities, and [...]
Middle Jurassic to Early Cretaceous orogenesis in the Klamath Mountains Province (northern California-southern Oregon) occurred by tectonic switching: Insights from Detrital zircon U-Pb geochronology of the Condrey Mountain schist
Published: 2024-01-11
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The Klamath Mountains province (KMP) of northern California and southern Oregon consists of generally east-dipping terranes assembled via Paleozoic to Mesozoic subduction along the western margin of North America. The KMP more than doubled in mass from Middle Jurassic to Early Cretaceous time, due to alternating episodes of extension (e.g, rifting and formation of the Josephine ophiolite) and [...]
Sensitivity Analysis of Global Kinematics on Mantle Structure Using Automatically Generated Adjoint Thermochemical Convection Codes
Published: 2023-12-11
Subjects: Earth Sciences, Geophysics and Seismology, Numerical Analysis and Scientific Computing, Tectonics and Structure
Within the past 30 years, numerical models of mantle convection have been able to predict observations on Earth and planets, and among them tectonics. The possibility of building inverse problems in global geodynamics became concrete, and often involve the development of adjoint codes. Such tools provide efficient ways to estimate sensitivities of misfit functions relative to control parameters, [...]
Petrological Evolution and Mass Redistribution in Basaltic Fault Zones: An Example from the Faroe Islands, North Atlantic Igneous Province
Published: 2023-11-06
Subjects: Earth Sciences, Geochemistry, Geology, Tectonics and Structure
Fault rock petrology exerts an important control on the permeability structure and mechanical properties of fault zones. Slip-related deformation on upper-crustal faults in basaltic rocks is closely associated with fluid-rock interaction, altering the distribution of physical properties within the fault. Here we present quantitative descriptions of the geochemical and petrological evolution of [...]
Quantifying fault interpretation uncertainties and their impact on fault seal and seismic hazard analysis
Published: 2023-10-31
Subjects: Geology, Tectonics and Structure
Fault-horizon cut-off data extracted from seismic reflection datasets are used to study the geometry, displacement distribution, and growth history of normal faults. Our study assesses the influence of three fault interpretation factors (repeatability, measurement obliquity, and cut-off type) on derived fault properties. We investigate uncertainties in throw, heave, displacement, and dip, [...]
Coral geochemical response to uplift in the aftermath of the 2005 Nias-Simeulue earthquake
Published: 2023-10-07
Subjects: Environmental Indicators and Impact Assessment, Geochemistry, Geomorphology, Natural Resources and Conservation, Tectonics and Structure
On 28 March 2005, the Indonesian islands of Nias and Simeulue experienced a powerful Mw 8.6 earthquake and widespread co-seismic uplift and subsidence. In areas of coastal uplift (up to ~2.8 m), fringing reef coral communities were killed by exposure, while deeper corals that survived were subjected to habitats with altered runoff, sediment and nutrient regimes. Here we present time-series [...]
The Role of Continental Heterogeneity on the Evolution of Continental Margin Topography at Subduction Zones
Published: 2023-09-01
Subjects: Earth Sciences, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The nature of the overriding plate plays a major role in shaping subduction zone processes. In particular, the highly heterogeneous continental lithosphere modulates intra-plate tectonics and the surface evolution of our planet. However, the role of continental heterogeneity is relatively under-explored for the dynamics of subduction models. We investigate the influence of rheological and density [...]