Preprints
Filtering by Subject: Tectonics and Structure
Transient rivers characterize evolving crustal-scale flexure in the Corinth Rift
Published: 2019-01-10
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Crustal elastic flexure on the flanks of rift-forming faults is a key feature to characterize continental rifting processes that can be resolved by means of transient river drainages on rift footwalls. Here we show that the elastic flexure dynamics of the uplifting southern shoulder of the rapidly-extending, asymmetric Corinth Rift (Greece) are recorded in 3D by its fluvial network. We explore [...]
Anticline growth by shortening during crustal exhumation of the Moroccan Atlantic margin
Published: 2019-01-10
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
It is unclear how the crustal-scale erosional exhumation of continental domains of the Moroccan Atlantic margin and the excessive subsidence of its rifted domains affected the Late Jurassic-Early Cretaceous post-rift evolution of the margin. To constrain the km-scale exhumation, we study the structural evolution of the Jbel Amsittene. This anticline is located on the coastal plain of the [...]
Structural evolution and medium-temperature thermochronology of central Madagascar: implications for Gondwana amalgamation
Published: 2019-01-06
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Madagascar occupied an important place in the amalgamation of Gondwana and preserves a record of several Neoproterozoic events that are linked to orogenesis of the East African Orogen. In this study, we integrate remote sensing, field data and thermochronology to unravel complex deformation in the Ikalamavony and Itremo domains of central Madagascar. The deformation sequence comprises a gneissic [...]
The Impact of Pre-salt Rift Topography on Salt Tectonics: a Discrete-Element Modelling Approach
Published: 2018-12-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Gravity-driven salt tectonics along passive margins is commonly depicted as domains of updip extension and downdip contraction linked by an intermediate, broadly undeformed zone of translation. This study expands on recently published physical models by applying discrete-element modelling to demonstrate how salt-related translation over pre-salt rift structures produce complex deformation and [...]
Base-Salt Relief Controls on Salt-Tectonic Structural Style, São Paulo Plateau, Santos Basin, Brazil
Published: 2018-12-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Base-salt relief influences salt flow, producing three-dimensionally complex strains and multiphase deformation within the salt and its overburden. Understanding how base-salt relief influences salt-related deformation is important to correctly interpret salt basin kinematics and distribution of structural domains, which have important implications to understand the development of key petroleum [...]
Can we relate the surface expression of dike-induced normal faults to subsurface dike geometry?
Published: 2018-12-14
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Dikes feed volcanic eruptions and drive crustal extension on Earth and other planetary bodies. Yet many dikes do not reach the surface, instead triggering normal faulting and graben formation in overlying rock. Whilst dike-induced faults provide a surficial and accessible record of active and ancient diking, unlocking these archives is difficult because we do not know how faults grow above or [...]
Episodic fluid flow in an active fault
Published: 2018-11-30
Subjects: Earth Sciences, Geology, Hydrology, Physical Sciences and Mathematics, Tectonics and Structure
We present a 250 ka record of episodic fluid flow along the Malpais fault which hosts the Beowawe hydrothermal system, Nevada, USA. The history of fluid flow was quantified using a novel combination of the apatite (U-Th)/He (AHe) thermochronometer and a model of the thermal effects of fluid flow. Samples show partial resetting of the AHe thermochronometer in a 40 m wide zone around the normal [...]
Evolving marginal terranes during Neoproterozoic supercontinent reorganisation: constraints from the Bemarivo Domain in northern Madagascar
Published: 2018-11-29
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Madagascar is important for unravelling the geodynamic evolution of the transition between the Rodinia and Gondwana supercontinents as it contains several suites of c. 850–700 Ma magmatic rocks that have been postulated to correlate with other ex-Rodinia terranes. The Bemarivo Belt of northern Madagascar contains the youngest suite of these magmatic rocks that date to c. 750–700 Ma. We present [...]
How do sea-level curves influence modeled marine terrace sequences?
Published: 2018-11-07
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Sequences of uplifted marine terraces are widespread and reflect the interaction between climatic and tectonic processes at multiple scales, yet their analysis is typically biased by the chosen sea-level (SL) curve. Here we explore the influence of Quaternary SL curves on the geometry of marine terrace sequences using landscape evolution models (LEMs). First, we modeled the young, rapidly [...]
A PCA-based framework for determining remotely-sensed geological surface orientations and their statistical quality
Published: 2018-11-07
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Planetary Geology, Planetary Sciences, Planetary Sedimentology, Statistical Methodology, Statistics and Probability, Stratigraphy, Tectonics and Structure
The orientations of planar rock layers are fundamental to our understanding of structural geology and stratigraphy. Remote-sensing platforms including satellites, unmanned aerial vehicles (UAVs), and LIDAR scanners are increasingly used to build three-dimensional models of structural features on Earth and other planets. Remotely-gathered orientation measurements are straightforward to calculate [...]
Growth folds above propagating normal faults
Published: 2018-11-07
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
Growth folds above the upper tips of normal faults are ubiquitous in extensional settings, especially during the early phases of extension and in salt-rich basins. As slip accumulates on the underlying normal fault, the geometry and size of the fold changes. These changes reflect the dip, throw, displacement and propagation rate of the underlying normal fault, as well as the thickness and [...]
Strike-slip reactivation of segmented normal faults: implications for basin structure and fluid flow
Published: 2018-11-05
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Reverse reactivation of normal faults, also termed ‘inversion’, has been extensively studied, whereas little is known about the strike-slip reactivation of normal faults. At the same time, recognizing strike-slip reactivation of normal faults in sedimentary basins is critical, as it may alter and impact basin physiography, accommodation and sediment supply and dispersal. Motivated by this, we [...]
Overpressure Transfer Through Interconnected Igneous Intrusions
Published: 2018-10-30
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Paper looking at the transference of overpressure through interconnected igneous intrusions within sedimentary basins. The manuscript highlights the current under-recognized hazard in both scientific and hydrocarbon drilling in vicinity of subsurface igneous complexes.
The deposition and alteration history of the northeast Syrtis Major layered sulfates
Published: 2018-10-15
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Ancient stratigraphy on Isidis Basins western margin records the history of water on early Mars. Noachian units are overlain by layered, basaltic-composition sedimentary rocks that are enriched in polyhydrated sulfates and capped by more resistant units. The layered sulfates – uniquely exposed at northeast Syrtis Major – comprise a sedimentary sequence up to 600-m thick that has undergone a [...]
High-temperature shear zone formation in Carrara marble: The effect of loading conditions
Published: 2018-09-26
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Rock deformation at depths in the Earth’s crust is often localized in high temperature shear zones occurring at different scales in a variety of lithologies. The presence of material heterogeneities is known to trigger shear zone development, but the mechanisms controlling initiation and evolution of localization are not fully understood. To investigate the effect of loading conditions on shear [...]