Preprints
Filtering by Subject: Tectonics and Structure
Deglaciation-enhanced mantle CO2 fluxes at Yellowstone imply positive climate feedback
Published: 2021-06-25
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Glaciology, Tectonics and Structure, Volcanology
The generation of mantle melts in response to decompression by glacial unloading has been linked to enhanced volcanic activity and volatile release in Iceland and in global eruptive records. However, it is unclear whether this process is also important in magmatically-active systems that do not show evidence of enhanced eruption rates. For example, the deglaciation of the Yellowstone ice cap did [...]
Rift kinematics preserved in deep-time erosional landscape below the northern North Sea
Published: 2021-06-25
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Our understanding of continental rifting is, in large parts, derived from the stratigraphic record. This record is, however, incomplete as it does not often capture the geomorphic and erosional signal of rifting. New 3D seismic reflection data reveals a Late Permian-Early Triassic landscape incised into the pre-rift basement of the northern North Sea. This landscape, which covers at least 542 [...]
An autonomous petrological database for geodynamic simulations of magmatic systems
Published: 2021-06-24
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Tectonics and Structure, Volcanology
Self-consistent modelling of magmatic systems is challenging as the melt continuously changes its chemical composition upon crystallization, which may affect the mechanical behaviour of the system. Melt extraction and subsequent crystallization create new rocks while depleting the source region. As the chemistry of the source rocks changes locally due to melt extraction, new calculations of the [...]
Insights into the compositional evolution of crustal magmatic systems from coupled petrological-geodynamical models
Published: 2021-06-24
Subjects: Geology, Geophysics and Seismology, Tectonics and Structure, Volcanology
The evolution of crustal magmatic systems is incompletely understood, as most studies are limited either by their temporal or spatial resolution. Exposed plutonic rocks represent the final stage of a long-term evolution punctuated by several magmatic events with different chemistry and generated under different mechanical conditions. Although the final state can be easily described, the nature of [...]
Paleomagnetism from multi-orogenic terranes is "not a simple game": Pyrenees' Paleozoic warning
Published: 2021-06-21
Subjects: Geophysics and Seismology, Tectonics and Structure
Paleomagnetism is a versatile tool in the Earth sciences: it provides critical input to geological time scales and plate tectonic reconstructions. Despite its undeniable perks, paleomagnetism is not without complications. Remagnetizations overprinting the original magnetic signature of rocks are frequent, especially in orogens which tend to be the areas with better rock exposure. Unraveling the [...]
Bayesian population correlation: A probabilistic approach to inferring and comparing population distributions for detrital zircon ages
Published: 2021-06-18
Subjects: Geochemistry, Probability, Statistical Methodology, Tectonics and Structure
Populations of detrital zircons are shaped by geologic factors such as sediment transport, erosion mechanisms, and the zircon fertility of source areas. Zircon U-Pb age datasets are influenced both by these geologic factors and by the statistical effects of sampling. Such statistical effects introduce significant uncertainty into the inference of parent population age distributions from detrital [...]
Microstructure and fluid flow in the vicinity of basin bounding faults in rifts – the Dombjerg Fault, NE Greenland rift system
Published: 2021-06-17
Subjects: Earth Sciences, Geology, Sedimentology, Tectonics and Structure
Faults commonly form loci for high fluid flux in sedimentary basins, where fluids, rocks and deformation processes frequently interact. Here, we elucidate the interaction of fluid flow, diagenesis and deformation near basin-bounding faults in sedimentary basins through a study in the vicinity (0-3.5 km) of the Dombjerg Fault in the NE Greenland rift system. Due to fault-controlled fluid [...]
Syn-Depositional Halokinesis in the Zechstein Supergroup (Lopingian) Controls Triassic Minibasin Genesis and Location
Published: 2021-06-03
Subjects: Geology, Sedimentology, Tectonics and Structure
Salt tectonics is typically caused by the flow of mobile evaporites in response to post-depositional gravity gliding and/or differential loading by overburden sediments. This situation is considerably more complex near the margins of salt basins, where carbonate and clastic rocks may be deposited at the same time and interbedded with more mobile evaporitic strata. In these cases, syn-depositional [...]
Tectonic Studies Group Equality Diversity and Inclusion report 2021
Published: 2021-05-28
Subjects: Earth Sciences, Geology, Tectonics and Structure
In 2021, the TSG Annual Meeting was held online due to the coronavirus pandemic. To build on our 2019 gender diversity report, we wanted to begin gathering diversity data proactively and anonymously. This will enable us to be more inclusive of marginalised genders, avoid mis-gendering participants and to collect a wider range of diversity data. We ran a survey of the presenters and session chairs [...]
Kinematic interaction between stratigraphically discrete salt layers; the structural evolution of the Corrib gas field, offshore NW Ireland
Published: 2021-05-27
Subjects: Tectonics and Structure
The kinematic interaction of thin salt layers during basin evolution has received little attention to date, despite there being several basins which contain multiple thin salt layers across NW Europe. This study utilises high-quality 3D seismic reflection data coupled with borehole data to investigate the evolution of the structure containing the Corrib gas field which is composed of two distinct [...]
Inferring rheology and geometry of subsurface structures by adjoint-based inversion of principal stress directions
Published: 2021-05-21
Subjects: Geology, Geophysics and Seismology, Tectonics and Structure
Imaging subsurface structures, such as salt domes, magma reservoirs, or subducting plates, is a major challenge in geophysics. Seismic imaging methods are, so far, the most precise methods to open a window into the Earth. However, the methods may not yield the exact depth or size of the imaged feature and may become distorted by phenomena such as seismic anisotropy, fluid flow, or compositional [...]
Tectonostratigraphy of the northern Okavango Delta and Rift Zone, Botswana
Published: 2021-05-21
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The Okavango Rift Zone (ORZ) and Okavango Delta in Northwest Botswana are Earth’s youngest continental rift system and largest inland delta. The delta and its underlying sediments record the effects of incipient rifting on the geomorphology and stratigraphy within the (incipient) southwestern arm of the East African Rift System in Botswana. Three open questions that we use river-borne [...]
Exhuming the Canadian Shield: preliminary interpretations from low-temperature thermochronology and significance for the sedimentary succession of the Hudson Bay Basin
Published: 2021-05-20
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
The geological history of the Canadian Shield is difficult to constrain because the sedimentary record is missing in those areas where Precambrian basement is exposed at the surface. This study presents preliminary results and interpretations of new apatite fission-track (AFT) analyses to elucidate the low-temperature (< 120 °C) history across Canada. The AFT modelling of samples from Southampton [...]
Influence of variable decoupling between vertically separated fault populations on structural inheritance – The Laminaria High, NW Shelf of Australia
Published: 2021-05-13
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
When extension events are greatly separated in time, older faults may be buried and stratigraphically separated from newly developing faults at shallower depths. During rifting, the buried structures may reactivate and propagate upwards to be expressed within the shallow system. The degree of linkage between structural levels determines the influence that the deeper structures can exert over the [...]
Structural Inheritance Controls Strain Distribution During Early Continental Rifting, Rukwa Rift
Published: 2021-05-13
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Little is known about rift kinematics and strain distribution during the earliest phase of extension due to the deep burial of the pre-rift and earliest rift structures beneath younger, rift-related deposits. Yet, this exact phase of basin development ultimately sets the stage for the location of continental plate divergence and breakup. Here, we investigate the structure and strain distribution [...]