Preprints
Filtering by Subject: Geology
Self-replicating subduction zone initiation by polarity reversal
Published: 2022-03-15
Subjects: Earth Sciences, Geology, Tectonics and Structure
Subduction zones have recurrently formed on Earth. Previous studies have, however, suggested that they are unlikely to start in the interior of a pristine ocean. Instead, they seem to be more likely to form from another pre-existing subduction zone. One widely cited conceptual model to start new subduction zones is polarity reversal, resulting from the shutdown of a pre-existent subduction zone [...]
The development of the eastern Orpheus rift basin, offshore eastern Canada: A case study of the interplay between rift-related faulting and salt deposition and flow
Published: 2022-03-12
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The salt-rich Orpheus rift basin, part of the eastern North American (ENAM) rift system, formed during the Late Triassic to Early Jurassic prior to opening of the Atlantic Ocean. Using a dense grid of 2D seismic-reflection lines, data from nearby wells, and information from adjacent ENAM rift basins, we have established a tectonostratigraphic framework, identified key structural elements, and [...]
Paleocene to Miocene southern Tethyan carbonate factories of the Southwestern and Western Central Asia
Published: 2022-03-11
Subjects: Geology, Paleobiology, Paleontology, Sedimentology
One hundred and forty-four sections of shallow-water carbonates, deposited between the Paleocene and the Miocene, from the Levant to the Himalaya, have been investigated to analyze the distribution of carbonate facies and carbonate producing organisms. Large benthic foraminifera resulted the volumetrically most important group of carbonate producers during the whole period, with a peak in [...]
Inverting passive margin stratigraphy for marine sediment transport dynamics over geologic time
Published: 2022-03-09
Subjects: Geology, Geomorphology, Sedimentology, Stratigraphy
Passive margin stratigraphy contains time-integrated records of landscapes that have long since vanished. Quantitatively reading the stratigraphic record using coupled landscape evolution and stratigraphic forward models (SFMs) is a promising approach to extracting information about landscape history. However, there is no consensus about the optimal form of simple SFMs because there has been a [...]
Geodynamics of continental rift initiation and evolution
Published: 2022-03-07
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Tectonics and Structure
A rift is a nascent plate boundary where continental lithosphere is extended and possibly broken. In the geologic past, rifting played a major role in shaping the surface of our planet, while at present, continental rifts are of societal relevance by hosting key georesources such as geothermal energy and ore deposits. This Review discusses fundamental rift processes, geodynamic forces and their [...]
Magma chamber detected beneath an arc volcano with high-resolution velocity images
Published: 2022-03-05
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Volcanology
Arc volcanoes are underlain by complex systems of molten-rock reservoirs ranging from melt-poor mush zones to melt-rich magma chambers. Petrological and satellite data indicate that eruptible magma chambers form in the topmost few kilometres of the crust. However, very few chambers have ever been definitively located, suggesting that most are too short-lived or too small to be imaged, which has [...]
Origin and kinematics of a basin-scale, non-polygonal, layer-bound normal fault system in the Levant Basin, eastern Mediterranean
Published: 2022-02-28
Subjects: Geology, Tectonics and Structure
Polygonal, layer-bound normal faults can extend over very large areas (>2,000,000 km2) of sedimentary basins. Best developed in very fine-grained rocks, these faults are thought to form during early burial in response to a range of diagenetic processes, including compaction and water expulsion. Local deviations from this idealised polygonal pattern are common; however, basin-scale, layer-bound [...]
Fault slip-rates and Coulomb stress interactions in the intersection zone of the Hope, Kelly and Alpine Faults, South Island, New Zealand
Published: 2022-02-24
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
The Hope Fault is a major strike-slip plate boundary fault in the Marlborough Fault Zone of New Zealand’s South Island that transfers slip between the Alpine Fault and Hikurangi subduction zone. We use lidar-based geomorphic and fault mapping, and optically stimulated luminescence (OSL; quartz) and infrared stimulated luminescence (IRSL; feldspar) dating of fault-proximal sedimentary deposits to [...]
Along-Dip Segmentation of the Slip Behavior and Rheology of the Copiapó Ridge Subducted in North-Central Chile
Published: 2022-02-24
Subjects: Geology, Geophysics and Seismology, Tectonics and Structure
We studied the along-dip influence of the Copiapó ridge subduction in the Atacama region, North-Central Chile by building a new seismicity catalog, including similar events and non-volcanic tremors (NVTs). We also obtained a 3-D tomographic model for P- and S-waves velocity (and the implied Vp/Vs ratio). We identify down-dip segmentation involving 4 distinct segments: a locked seismogenic zone [...]
Early evolution of the Adelaide Superbasin
Published: 2022-02-17
Subjects: Earth Sciences, Geochemistry, Geology, Sedimentology, Stratigraphy, Tectonics and Structure
Continental rifts have a significant role in supercontinent breakup, and the development of sedimentary basins. The Australian Adelaide Superbasin is one of the largest and best-preserved rift systems that initiated during the breakup of Rodinia, yet substantial challenges still hinder our understanding of its early evolution and place within the Rodinian supercontinent. In the past decade, our [...]
PyMelt: An extensible Python engine for mantle melting calculations
Published: 2022-02-13
Subjects: Earth Sciences, Geochemistry, Geology, Geophysics and Seismology, Volcanology
Modelling the melting of Earth’s mantle is crucial for understanding the distribution of volcanic activity on Earth and for testing models of mantle convection and mantle lithological heterogeneity. PyMelt is a new open-source Python library for calculating the melting behaviour of multi-lithology mantle and can be used to predict a number of geophysical and petrological observations, including [...]
Macrostratigraphy of the Ediacaran System in North America
Published: 2022-02-11
Subjects: Earth Sciences, Geochemistry, Geology, Paleontology, Sedimentology, Stratigraphy, Tectonics and Structure
Ediacaran sediments record the termination of Cryogenian ‘Snowball Earth’ glaciations, preserve the first occurrences of macroscopic metazoans, and contain one of the largest known negative δ13C excursions (the Shuram-Wonoka). The rock record for the transition between the Proterozoic and Phanerozoic in North America is also physically distinct, with much of the continent characterized by a wide [...]
Indian Plate paleogeography, subduction, and horizontal underthrusting below Tibet: paradoxes, controvercies, and opportunities
Published: 2022-02-06
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology, Tectonics and Structure, Volcanology
The India-Asia collision zone is the archetype to calibrate geological responses of continent-continent collision, but hosts a paradox: there is no orogen-wide geological record of oceanic subduction after initial collision around 60-55 Ma, yet thousands of kilometers of post-collisional subduction occurred before arrival of unsubductable continental lithosphere that currently horizontally [...]
Timing of the last deglaciation phases in the southern Baltic area inferred from Bayesian age modeling
Published: 2022-02-03
Subjects: Earth Sciences, Geology, Geomorphology
A new chronology of the last Scandinavian Ice Sheet retreat in the southern Baltic basin is proposed. Based on Bayesian age modeling, we show that the most likely ages of particular deglaciation phases are 16.5 ± 0.5 ka for the Gardno Phase, 15.6 ± 0.6 ka for the Słupsk Bank Phase, and 13.9 ± 0.5 ka for the Southern Middle Bank Phase. The Gardno moraines are correlated with the Halland Coastal [...]
Seismic Geomorphology of a Late Cretaceous Turbidite Channel system in Deepwater Kribi/Campo sub-basin, offshore Cameroon
Published: 2022-01-28
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
In this study, a seismic reflection dataset and well-log data were integrated to investigate the geometry and internal configuration of a turbidite channel system within the Late Cretaceous interval of the deep-water Kribi-Campo sub-basin, offshore Cameroon. This interval is characterized by a well-developed submarine channel system consisting of an early and a late-stage channel. [...]