Preprints
Filtering by Subject: Tectonics and Structure
On seismicity and structural style of oceanic transform faults: a field geological perspective from the Troodos ophiolite, Cyprus
Published: 2019-09-06
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Aseismic creep accommodates the majority of displacement along active oceanic transform faults, also within their thermally defined seismogenic zone. The significant earthquakes that do occur are near periodic, and repeat in nearly constant locations. Neither of these observations is explained by current models that infer an olivine-dominated rheology and a thermally controlled seismogenic zone. [...]
Controls on variations in minibasin geometries: Lower Congo Basin, offshore Angola
Published: 2019-08-30
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
In passive margin salt basins, the distinct tectonic domains of thin-skinned extension and contraction exert important controls on the geometry and evolution of minibasins. In this study, we use a semi-regional 3D seismic dataset from the Lower Congo Basin to investigate the spatial and temporal evolution of a network of salt-related minibasins and intervening salt walls and diapirs during [...]
Subduction history reveals Cretaceous slab superflux as a possible cause for the mid-Cretaceous plume pulse and superswell events
Published: 2019-08-29
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Subduction is a fundamental mechanism of material exchange between the planetary interior and the surface. Despite its significance, our current understanding of fluctuating subducting plate area and slab volume flux has been limited to a range of proxy estimates. Here we present a new detailed quantification of subduction zone parameters from the Late Triassic to present day (230 – 0 Ma). We use [...]
Review paper: The 2nd June 1979 Mw 6.1 Cadoux surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 2nd June 1979 moment magnitude (Mw) 6.1 Cadoux earthquake caused a complex, multi-fault surface rupture consisting of six mapped scarps: (from south to north) the 8 km long west dipping Robb scarp, 3 km long south dipping Cumming scarp, the Lone Tree, Carter and Tank scarps (which together define an east-dipping arcuate rupture) and the 2.5 km long southwest-dipping Kalajzic scarp. Surface [...]
Review paper: The 10th March 1970 Mw 5.0 Calingiri surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 10th March 1970 moment magnitude (Mw) 5.0 Calingiri earthquake surface rupture is 3.3 km long with a maximum vertical displacement of 0.4 m. The fault as defined by surface measurements is a shallow-dipping reverse fault (~ 20° east) with a probable shallow hypocentre (< 1 km). This is consistent with published hypocentral depths, though large uncertainties exist within the seismological [...]
Review paper: The 30th March 1986 Mw 5.7 Marryat Creek surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 30th March 1986 Mw 5.7 Marryat Creek earthquake produced a highly arcuate 13 km long surface rupture with maximum vertical displacement of 0.9 m. Sinistral displacement on the NE-SW limb, dextral displacement on the NNE-SSW limb, and maximum vertical displacement in the central apex of rupture supports SW over NE movement of a hanging-wall block. Epicentre locations are poorly constrained and [...]
Review paper: The 14th October 1968 Mw 6.6 Meckering surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 14th October 1968 MW 6.6 Meckering earthquake surface rupture is comprised of a main 37 km long concave Meckering scarp (with a 1.5 km wide dextral step-over along the Burges en-echelon rupture complex) and a minor 9 km long rupture on the Meckering scarp foot-wall (the Splinter scarp, also with a 1.5 km dextral step-over). We recommend a total surface rupture length of 44.4 km for [...]
Review paper: The 20th May 2016 Mw 6.1 Petermann surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 20th May 2016 Mw 6.1 Petermann earthquake produced a 21 km long surface rupture with a maximum vertical offset of 0.9 m. Geological and geophysical data provide strong evidence that rupture occurred along a mylonite foliation plane with an orientation defined by deformation from the nearby Woodroffe Thrust, a major Neoproterozoic terrane suture. The most geologically and seismologically [...]
Review paper: The 23rd March 2012 Mw 5.2 Pukatja surface rupturing earthquake, Australia
Published: 2019-08-17
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The 23rd March 2012 Mw 5.2 Pukatja earthquake produced an arcuate surface rupture 1.6 km long with a maximum vertical offset of 0.48 m. We reclassify its length to 1 km based on application of orientation and kinematic criteria used previously to measure other historic Australian surface ruptures. Epicentres are poorly constrained and inaccurate, located up to 17 km from the surface rupture with [...]
The influence of structural inheritance and multiphase extension on rift development, the northern North Sea
Published: 2019-08-07
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The northern North Sea rift evolved through multiple rift phases within a highly heterogeneous crystalline basement. The geometry and evolution of syn-rift depocentres during this multiphase evolution, and the mechanisms and extent to which they were influenced by pre-existing structural heterogeneities remain elusive, particularly at the regional scale. Using an extensive database of [...]
Deep-water reservoir distribution on a salt-influenced slope, Santos Basin, offshore Brazil
Published: 2019-08-07
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Studies of near-seabed datasets show that salt tectonics controls the distribution and architecture of deep-water reservoirs in many salt-influenced basins. It is typically difficult, however, to study the distribution and stratigraphic evolution of depositional systems preserved at deeper, economically significant depths, reflecting poor seismic imaging of steeply dipping strata flanking [...]
A mechanistic erosion model for cosmogenic nuclide inheritance in fluvial single-clast exposure ages
Published: 2019-08-06
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Statistics and Probability, Tectonics and Structure
Terrestrial cosmogenic nuclides (TCNs), produced by the bombardment of Earth’s surface by cosmic rays, are widely used for age-dating and pacing surface processes. Sediments carry an inherited TCN concentration, useful for quantifying erosion and transport rates, but that must be subtracted when age-dating sedimentary landforms, such as alluvial fans. Here we present a mechanistic model of [...]
Onset of slip partitioning under oblique convergence within scaled physical models
Published: 2019-08-04
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Oblique convergent margins host slip partitioned faults with simultaneously active strike-slip and reverse faults. Such systems defy energetic considerations that a single oblique-slip fault accommodates deformation more efficiently than multiple faults. To investigate the development of slip partitioning, we record deformation throughout scaled experiments of wet kaolin over a low convergence [...]
The Byers Basin: Jurassic-Cretaceous tectonic and depositional evolution of the forearc deposits of the South Shetland Islands and its implications for the northern Antarctic Peninsula
Published: 2019-07-31
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
This paper addresses the Jurassic–Cretaceous stratigraphic evolution of fore-arc deposits exposed along the west coast of the northern Antarctic Peninsula. In the South Shetland Islands, Upper Jurassic deep-marine sediments are uncomformably overlain by a Lower Cretaceous volcaniclastic sequence that crops out on Livingston, Snow and Low islands. U-Pb zircon ages are presented for the upper [...]
The Gondwanan margin in West Antarctica: insights from Late Triassic magmatism of the Antarctic Peninsula
Published: 2019-07-31
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Triassic orthogneisses of the Antarctic Peninsula provide evidence for the Palaeozoic and Mesozoic geological evolution of southern Gondwana within Pangaea. These rocks are sporadically exposed in southeastern Graham Land and northwestern Palmer Land, although reliable geochronological, geochemical and isotopic data are sparse. We combine new geochronological (LA-ICP-MS zircon U-Pb), geochemical, [...]