Preprints
Filtering by Subject: Tectonics and Structure
Pleistocene-Holocene tectonic reconstruction of the Ballık travertine (Denizli Graben, SW Turkey): (De)formation of large travertine geobodies at intersecting grabens
Published: 2018-09-25
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Travertine geobodies have been identified as potential reservoir analogues to carbonate build-ups in pre-salt hydrocarbon systems. To investigate travertine geobody deformation, faults were mapped in 35 travertine quarries that excavate the Ballık travertine, i.e. a c. 12.5 km2 large travertine geobody that precipitated at the intersection of the NE margin of the Denizli Basin and neighbouring [...]
Interpretation of low‐temperature thermochronometer ages from tilted normal fault blocks
Published: 2018-09-25
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Low-temperature thermochronometry is a widely-used tool for dating the timing and rate of slip on normal faults. Rates are often derived from suites of footwall thermochronometer samples, but simple 2D regression of age vs. structural depth fails to account for the fact that rocks collected at similar elevations today experienced curved particle trajectories and variable velocities during fault [...]
Controls of basement fabric on rift coupling and development of normal fault geometries: Insights from the Rukwa – North Malawi Rift
Published: 2018-08-19
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The Rukwa Rift and North Malawi Rift Segments (RNMRS) both define a major rift-oblique segment of the East African Rift System (EARS), and although the two young rifts show colinear approaching geometries, they are often regarded as discrete rifts due to the presence of the intervening Mbozi Block uplift located in-between. This problem has been complicated by the dominance of the Rungwe volcanic [...]
Using polygonal layer-bound normal faults as tools to delimit clastic reservoirs in the Levant Basin offshore Lebanon
Published: 2018-08-19
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Tectonics and Structure
The Levant Basin offshore Lebanon contains an array of layer-bound normal faults in the Oligo-Miocene units. The faults are believed to have nucleated in soft-grained sediments similar to polygonal fault systems worldwide, and as a result are influenced by lithological heterogeneities in the host rock unit. We used 3D seismic data and amplitude extraction from offshore Lebanon to map deepwater [...]
Zealandia 2008
Published: 2018-08-16
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Zealandia is a submerged continent in the southwest Pacific Ocean that can be regarded as a rifted part of eastern Australia and West Antarctica. Described simply, the pre-Gondwana-breakup Zealandia geological record is one of a Cambrian to Early Cretaceous Gondwana convergent margin, followed by Late Cretaceous continental rifting. Arizona Geological Society Digest 22, 227-233.
Weak and slow, strong and fast: How shear zones evolve in a dry continental crust (Musgrave Ranges, Central Australia)
Published: 2018-08-15
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The strike-slip Davenport Shear Zone in Central Australia developed during the Petermann Orogeny (~ 550 Ma) in an intracontinental lower crustal setting under dry sub-eclogite facies conditions (~ 650 °C, 1.2 GPa). This ca. 5 km wide mylonite zone encloses several large low-strain domains, allowing a detailed study of the initiation of shear zones and their progressive development. [...]
Capturing the Mesoarchean Emergence of Continental Crust in the Coorg Block, Southern India
Published: 2018-07-17
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Tectonics and Structure
The emergence of Earths continental crust above sea‐level is debated. To assess whether emergence can be observed at a regional scale, we present zircon U‐Pb‐Hf‐O isotope data from magmatic rocks of the Coorg Block, southern India. A 3.5 Ga granodiorite records the earliest felsic crust in the region. Younger phases of magmatism at 3.37‐3.27 Ga and 3.19‐3.14 Ga, comprising both reworked crust and [...]
Historical trajectories of disaster risk in Dominica
Published: 2018-07-13
Subjects: Earth Sciences, Environmental Sciences, Natural Resources Management and Policy, Physical Sciences and Mathematics, Soil Science, Tectonics and Structure, Water Resource Management
The calamitous consequences of Hurricane Maria (2017) for the Caribbean island of Dominica highlighted the acute and increasing susceptibility of the region to hazard events. Despite the increasing international attention given to disaster risk reduction, recovery from hazard events can be especially lengthy and difficult for Small Island Developing States. In this paper we build on existing [...]
Strain Localization and Weakening Processes in Viscously Deforming Rocks: Numerical Modeling Based on Laboratory Torsion Experiments
Published: 2018-07-12
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Localization processes in the viscous lower crust lead to the formation of deformation zones over a broad range of scales that may affect the mechanical response of faults in the upper crust during the entire seismic cycle. In order to gain detailed insight into the processes involved in strain localization and rheological weakening in viscously deforming rocks we conduct centimeter-scale [...]
Tectonic and oceanographic process interactions archived in the Late Cretaceous to Present deep-marine stratigraphy on the Exmouth Plateau, offshore NW Australia
Published: 2018-07-11
Subjects: Earth Sciences, Engineering, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Deep-marine deposits provide a valuable archive of process interactions between sediment gravity flows, pelagic sedimentation, and thermo-haline bottom-currents. Stratigraphic successions can also record plate-scale tectonic processes (e.g. continental breakup and shortening) that impact long-term ocean circulation patterns, including changes in climate and biodiversity. One such setting is the [...]
Coseismic extension recorded within the damage zone of the Vado di Ferruccio Thrust Fault, Central Apennines, Italy
Published: 2018-07-02
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Recent high resolution hypocentral localisation along active fault systems in the Central Apennines illuminates the activation of seismogenic volumes dipping at low angle (<30°) in extensional settings overprinting contractional deformations affecting the continental crust of the Adria microplate. Individuation of the geological structures and of the fault processes associated with these [...]
Exhumation of (U)HP/LT rocks caused by diachronous slab breakoff
Published: 2018-06-20
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Three-dimensional thermo-mechanical analogue models investigate how diachronous slab breakoff may lead to the exhumation of subducted continental crust. Slab breakoff initiates spontaneously in one location and migrates laterally along the plate boundary, causing a transient excess downward pull force on the plate boundary in front of the propagating slab tear. This pull force locally reduces the [...]
How do intra-basement fabrics influence normal fault growth? Insights from the Taranaki Basin, offshore New Zealand
Published: 2018-06-14
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Pre-existing intra-basement structures can have a strong influence on the evolution of rift basins. Although 3D geometric relationships provide some insight into how intra-basement structures determine the broad geometry and spatial development (e.g. strike and dip) of rift-related faults, little is known about the impact of the former on the detailed kinematics (i.e. nucleation and tip [...]
Is the Earth Lazy? A review of work minimization in fault evolution
Published: 2018-06-12
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The principle of work minimization has been used in various forms to account for the development of active fault systems within a wide range of tectonic settings. We review the successes, challenges and implications learned from previous applications of work minimization. Examination of the energy budget provides insight into the competing influences of different processes within fault systems [...]
New analogue materials for nonlinear lithosphere rheology, with an application to slab break-off
Published: 2018-06-07
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Stress-dependent nonlinear upper mantle rheology has a firm base in rock mechanical tests, where this nonlinearity results from dislocation creep of minerals. In the last few decades there has been some attention to nonlinear, power-law, materials for application in scaled analogue experiments for tectonic processes. However, studies describing the rheology of analogue materials with the same [...]