Preprints
Filtering by Subject: Tectonics and Structure
Active deformation and Plio-Pleistocene fluvial reorganization of the western Kura Fold-Thrust Belt, Georgia: implications for the evolution of the Greater Caucasus mountains and seismic hazard
Published: 2019-12-31
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Since the Plio-Pleistocene, southward migration of shortening in the eastern part of the Greater Caucasus (GC) into the Kura foreland basin has progressively formed the Kura-Fold Thrust belt (KFTB) and Alazani piggyback basin, which separates the KFTB from the GC. Previous work argued for an eastward propagation of the KFTB, implying that the western portion in Georgia is the oldest, but this [...]
Back-propagating super-shear rupture in the 2016 Mw7.1 Romanche transform fault earthquake
Published: 2019-12-26
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
How an earthquake rupture propagates strongly influences potentially destructive ground shaking. Complex ruptures often involve slip along multiple faults, masking information on the frictional behaviour of fault zones. Geometrically smooth ocean transform fault plate boundaries offer a favourable environment to study fault dynamics, because strain is accommodated along a single, wide fault zone [...]
Stratigraphic reservoir compartmentalization: causes, recognition, and implications for the geological storage of carbon dioxide
Published: 2019-11-23
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
The impact of carbon capture and storage (CCS) in mitigating anthropogenic emissions of greenhouse gases is potentially great, but its success is strongly dependent on identifying suitable geological storage sites. One of the key uncertainties in this regard is the degree of compartmentalization of the target storage horizon. Many studies have examined reservoir compartmentalization in oil and [...]
Ancient subducted oceans controlling the positioning of deep mantle plumes
Published: 2019-11-08
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Seismic imaging of the Earths interior reveals plumes originating from relatively hot regions of the lower mantle, surrounded by cooler material thought to be remnants of ancient subducted oceans. Based largely on geophysical data, two opposing hypotheses dominate the discussion on dynamics at the base of mantle: the large hot anomalies are thermo-chemical in nature; or, alternatively, they are [...]
Growth, overprinting, and stabilization of Proterozoic Provinces in the southern Lake Superior region
Published: 2019-11-08
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Tectonics and Structure
New geochronologic data in the southern Lake Superior region provide key information on the timing and nature of tectonic activity that pre-and post-date initial Paleoproterozoic growth of Laurentia during the geon 18 Penokean orogeny. The obducted Pembine ophiolite formed along the edge of a Paleoproterozoic ocean basin at least 30 m.y. prior to Penokean island arc/microcontinent accretion [...]
The variation and visualisation of elastic anisotropy in rock-forming minerals
Published: 2019-11-01
Subjects: Earth Sciences, Geochemistry, Geology, Geophysics and Seismology, Mineral Physics, Physical Sciences and Mathematics, Tectonics and Structure
All minerals behave elastically, a rheological property that controls their ability to support stress, strain and pressure, the nature of acoustic wave propagation and influences subsequent plastic (i.e. permanent, non-reversible) deformation. All minerals are intrinsically anisotropic in their elastic properties – that is, they have directional variations that are related to the configuration [...]
Surface faulting earthquake clustering controlled by fault and shear-zone interactions
Published: 2019-10-25
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Surface faulting earthquakes are known to cluster in time, from historical and palaeoseismic studies, but the mechanism(s) responsible for clustering, such as fault interaction, strain-storage, and evolving dynamic topography, are poorly quantified, and hence not well understood. We present a quantified replication of observed earthquake clustering in central Italy. Six active normal faults are [...]
Inheritance of penetrative basement anisotropies by extension-oblique faults: Insights from analogue experiments
Published: 2019-10-24
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
During rifting, pre-existing penetrative basement fabrics can affect new faults in cover rocks by a mechanism that does not appear to involve reactivation. This subtle form of inheritance can significantly impact fault network architecture in rift basins above laterally variable basement domains with geomechanical anisotropies. Here we use multi-layer, brittle-ductile, crustal-scale analogue [...]
Dynamic fault parameters preprint
Published: 2019-10-24
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The behavior of faults under dynamic loading reflects the response of the shape and composition of the fault to the applied mechanical loading and environmental conditions. The interaction between the fault properties and the loading system is controlled by multiple variables that may generate an inherently complex behavior. The usage of multi-parametric variables can illuminate the controlling [...]
Distributed normal faulting in the tip zone of the South Alkyonides Fault System, Gulf of Corinth, constrained using 36Cl exposure dating of Late-Quaternary wave-cut platforms.
Published: 2019-10-24
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
In order to investigate the geometry, rates and kinematics of active faulting in the region close to the tip of a major crustal-scale normal fault in the Gulf of Corinth, Greece, we have mapped faults and dated their offsets using a combination of 234U/230Th coral dates and in situ 36Cl cosmogenic exposure ages for sediments and wave-cut platforms deformed by the faults. Our results show that [...]
Pre-breakup extension in the northern North Sea defined by complex strain partitioning and heterogeneous extension rates
Published: 2019-10-24
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The early stages of continental rifting are accommodated by the growth of upper-crustal normal fault systems that are distributed relatively evenly across the rift width. Numerous fault systems define fault arrays, the kinematics of which are poorly understood due to a lack of regional studies drawing on high-quality subsurface data. Here we investigate the long-term (~150 Myr) growth of a [...]
Rotation, narrowing, and preferential reactivation of brittle structures during oblique rifting
Published: 2019-10-24
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Occurrence of multiple faults populations with contrasting orientations in oblique continental rifts and passive margins has long sparked debate about relative timing of deformation events and tectonic interpretations. Here, we use high-resolution three-dimensional thermo-mechanical numerical modeling to characterize the evolution of the structural style associated with varying geometries of [...]
Rock strength and structural controls on fluvial erodibility: implications for drainage divide mobility in a collisional mountain belt
Published: 2019-10-13
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Numerical model simulations and experiments have suggested that when migration of the main drainage divide occurs in a mountain belt, it can lead to the rearrangement of river catchments, rejuvenation of topography, and changes in erosion rates and sediment flux. We assess the progressive mobility of the drainage divide in three lithologically and structurally distinct groups of bedrock in the [...]
“Conjugate margins” – An oversimplification of the complex southern North Atlantic rift and spreading system?
Published: 2019-10-13
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The prevalence of conjugate margin terminology and studies in the scientific literature is testimony to the contribution that this concept and approach has made to the study of passive margins, and more broadly extensional tectonics. However, when applied to the complex rift, transform and spreading system of the southern North Atlantic (i.e. the passive margins of Newfoundland, Labrador, [...]
Making mountains on Earth and beyond
Published: 2019-10-13
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Many of Earth’s mountains are formed in orogenic belts aligned along plate margins. Their altitudes (reaching >8,000 m above sea level in the Himalayas) are the result of the balance between tectonic forces causing their uplift and erosive processes causing their destruction. The tectonic forces result, in part, from isostacy which is determined by the plasticity of the asthenosphere, but [...]