Preprints
Filtering by Subject: Geology
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 [...]
30-year record of Himalaya mass-wasting reveals landscape perturbations by extreme events
Published: 2021-06-18
Subjects: Earth Sciences, Geology, Geomorphology
In mountainous environments, quantifying the drivers of mass-wasting is fundamental for understanding landscape evolution and improving hazard management. Here, we quantify the magnitudes of mass-wasting caused by the Asia Summer Monsoon (ASM), extreme rainfall and earthquakes in the Nepal Himalayas. Using a newly compiled 30-year mass-wasting inventory, we establish empirical relationships [...]
Characteristics of landslide path dependency revealed through multiple resolution landslide inventories in the Nepal Himalaya
Published: 2021-06-18
Subjects: Earth Sciences, Geology, Geomorphology
Recent research in Umbria, Italy, has shown that landslide susceptibility is controlled by a process called path-dependency, which describes how past landslides control the locations of future landslides. To date, landslide path-dependency has only been characterised in Italy. This raises the question of whether this process occurs in other geomorphic settings, and thus whether path-dependency [...]
Channel, dune and sand sheet architectures of strait-adjacent deltas, Rifian Corridor, Morocco
Published: 2021-06-17
Subjects: Earth Sciences, Geology, Sedimentology, Stratigraphy
Sea strait geographies amplify tidal currents, which can result in the formation of tidal strait deposits with a symmetrical facies arrangement. It can be problematic to distinguish such confined tidal strait deposits from strait systems that developed in less constricted settings. To push a more robust differentiation between the confined tidal strait model and a model for less constricted tidal [...]
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 [...]
Spatial and morphometric relationships of submarine landslides offshore west and southwest Iberia
Published: 2021-06-08
Subjects: Earth Sciences, Geology, Geomorphology, Sedimentology, Stratigraphy
Submarine landslides are ubiquitous geohazards in marine environments occurring at multiple scales. Increasing efforts have been made to catalogue and categorise submarine landslides in comprehensive databases, aiming to better understand their preconditioning and trigger factors. Using the recently compiled, open-access MAGICLAND dataset, we investigate the distribution and morphometric trends [...]
Spatial characteristics and kinematics of floodplain aggradation cycles in the lower Eocene Willwood Formation of the Bighorn Basin, Wyoming, USA
Published: 2021-06-07
Subjects: Geology, Sedimentology, Stratigraphy
Interaction of allogenic and autogenic forcing in building alluvial stratigraphy remains a complex subject that is critical for paleoenvironmental and paleoclimate reconstruction and subsurface rock property prediction. Autogenic processes may act at similar vertical and lateral scales at which astronomical climate forcing drives alluvial stratigraphic deposition, making it difficult to [...]
Interphase misorientation as a tool to study metamorphic reactions and crystallization in geological materials
Published: 2021-06-07
Subjects: Geology, Mineral Physics, Other Earth Sciences
Interphase boundaries are planar defects that separate two different minerals, which in general have different compositions and/or crystalline structures and may play an important role as a pathway for fluids in rocks and affect their physical properties. For the proper characterization of interphase boundaries, one needs to define the misorientation between adjacent grains and the orientation of [...]
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 [...]
Ductile deformation during carbonation of serpentinized peridotite
Published: 2021-06-01
Subjects: Geology
Carbonated serpentinites (listvenites) in the Oman Ophiolite record mineralization of several GT of CO2, but the mechanisms providing permeability for continued reactive fluid flow are unclear. Samples of the Oman Drilling Project show that listvenites with a penetrative foliation have abundant microstructures related to crystal growth and indicate that the carbonation reaction occurred during [...]
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 [...]
Deep-water syn-rift stratigraphy as archives of Early-Mid Pleistocene palaeoenvironmental signals and controls on sediment delivery
Published: 2021-05-27
Subjects: Earth Sciences, Geology, Geomorphology, Sedimentology, Stratigraphy
The timing and character of coarse siliciclastic sediment delivered to deep-water environments in active rift basins is governed by the complicated interactions of tectonics, climate, eustasy, hinterland geology, and shelf process regime. The stratigraphic archives of deep-water syn-rift basin-fills provide records of palaeoenvironmental changes (e.g. climate and vegetation) in onshore [...]
Meteorites that produce K-feldspar-rich ejecta blankets correspond to mass extinctions.
Published: 2021-05-24
Subjects: Applied Statistics, Atmospheric Sciences, Earth Sciences, Geology, Other Planetary Sciences, Paleontology, Physical Sciences and Mathematics
Meteorite impacts load the atmosphere with dust and cover the Earth‘s surface with debris. They have long been debated as a trigger of mass extinctions through Earth‘s history. Impact winters generally last <100 years, whereas ejecta blankets persist for 10^3-10^5 years. Here we show that only meteorite impacts that emplaced ejecta blankets rich in K-feldspar (Kfs) correlate to Earth system [...]
What sets aeolian dune height?
Published: 2021-05-23
Subjects: Climate, Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Earth's major sand seas are often populated with giant dunes, up to hundreds of meters in height and kilometers in wavelength. These massive sediment piles, visible from space on our planet and across the Solar System, indicate that conditions for sand transport have persisted for millenia. Unraveling how giant dunes form therefore has implications for understanding atmospheric flows and climatic [...]