Preprints
Filtering by Subject: Geology
Salt-detached strike-slip faulting, Outer Kwanza Basin, Offshore Angola
Published: 2022-05-25
Subjects: Geology, Geophysics and Seismology, Stratigraphy, Tectonics and Structure
We here use a 3D seismic reflection dataset from Outer Kwanza Basin, offshore Angola to examine the structure and growth of salt-detached strike-slip faults. The faults occur in four, up to 13.8 km-long, NE-trending arrays that are physically linked by restraining bend and releasing stepovers, and which presently overlie Aptian salt and base-salt relief related to pre-salt faulting. We suggest [...]
Using Synthetic Data Trained Convolutional Neural Network For Predicting Sub-Resolution Thin Layers From Seismic Data
Published: 2022-05-19
Subjects: Artificial Intelligence and Robotics, Geology, Geophysics and Seismology
Numerous studies have demonstrated the capability of supervised deep learning techniques for predicting geological features of interest from seismic sections, including features that are difficult to identify using traditional interpretation methods. However, successful application of these techniques in practice has been limited by the difficulty of obtaining large training dataset where seismic [...]
A very unconventional hydrocarbon play: the Mesoproterozoic Velkerri Formation of Northern Australia
Published: 2022-05-16
Subjects: Geochemistry, Geology, Sedimentology, Stratigraphy, Tectonics and Structure
The ca. 1.5–1.3 Ga Roper Group of the greater McArthur Basin is a component of one of the most extensive Precambrian hydrocarbon-bearing basins preserved in the geological record, recently assessed as containing 429 million barrels of oil and eight trillion cubic feet of gas (in place). It was deposited in an intra-cratonic sea, referred to here as the McArthur-Yanliao Gulf. The Velkerri [...]
Hydraulic fracturing: Laboratory evidence of the brittle-to-ductile transition with depth
Published: 2022-05-13
Subjects: Earth Sciences, Engineering, Geology, Petroleum Engineering
Understanding the propagation of hydraulic fracture (HF) is essential for effectively stimulating the hydrocarbon production of unconventional reservoirs. Hydraulic fracturing may induce distinct failure modes within the formation, depending on the rheology of the solid and the in-situ stresses. A brittle-to-ductile transition of HF is thus anticipated with increasing depth, although only scarce [...]
Complex fault system revealed from 3-D seismic reflection data with deep learning and fault network analysis
Published: 2022-05-13
Subjects: Artificial Intelligence and Robotics, Geology, Geophysics and Seismology, Tectonics and Structure
Understanding where normal faults are is critical to an accurate assessment of seismic hazard, the successful exploration for and production of natural (including low-carbon) resources, and for the safe subsurface storage of CO2. Our current knowledge of normal fault systems is largely derived from seismic reflection data imaging intra-continental rifts and continental margins. However, [...]
The CREp 36Cl exposure age calculator: development version “dev”
Published: 2022-05-04
Subjects: Geochemistry, Geology, Geomorphology, Glaciology, Sedimentology, Tectonics and Structure, Volcanology
Chlorine-36 (36Cl) is currently the only in situ cosmogenic nuclide applicable in carbonates, Ca- and K-rich feldspars and aphyric silicate rocks. Because the production reactions of 36Cl are more numerous and complex than those of other cosmogenic nuclides (e.g. 10Be, 3He), comprehensive and user-friendly calculators are essential for routine application of 36Cl to Earth surface research [...]
Arctic sediment routing during the Triassic - sinking the Arctic Atlantis
Published: 2022-05-02
Subjects: Geology
Opening of the Arctic Ocean has been the subject of much debate, and the placement of terranes in Early Mesozoic remains a crucial part of this important discussion. Several continental terranes complicate the paleogeographic reconstruction. One such terrane is Crockerland, which has been inferred to explain sediment distribution in the Arctic throughout the Mesozoic. However, the Triassic [...]
Magnetic fabrics reveal three-dimensional flow processes within elongate magma fingers at the margin of the Shonkin Sag laccolith (MT, USA)
Published: 2022-04-29
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Unravelling magma flow in ancient sheet intrusions is critical to understanding how magma pathways develop and feed volcanic eruptions. Analyzing the shape preferred orientation of minerals in intrusive rocks can provide information on magma flow, because crystals may align parallel to the primary flow direction. Anisotropy of magnetic susceptibility (AMS) is an established method to quantify [...]
HYDROGEN-INDUCED CALCITE DISSOLUTION IN AMALTHEENTON FORMATION CLAYSTONES: IMPLICATIONS FOR UNDERGROUND HYDROGEN STORAGE CAPROCK INTEGRITY
Published: 2022-04-22
Subjects: Geology, Physical Sciences and Mathematics
With the rising potential of underground hydrogen storage (UHS) in depleted oil and gas reservoirs or deep saline aquifers, questions remain regarding changes to geological units due to interaction with injected hydrogen. Of particular importance is the integrity of potential caprocks/seals with respect to UHS. The results of this study show significant dissolution of calcite fossil fragments in [...]
Late Glacial and Holocene Palaeolake History of the Última Esperanza Region of Southern Patagonia
Published: 2022-03-29
Subjects: Earth Sciences, Geochemistry, Geology, Geomorphology, Glaciology, Hydrology, Paleobiology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Volcanology
We undertook multiproxy analyses on two sediment cores from Lago Pato, a small lake basin at 51°S topographically separated from Lago del Toro in Torres del Paine (TdP), to provide insights into glacier dynamics and lake level change in the TdP and Última Esperanza region over the last ~30,000 cal a BP (30 ka). Lago Pato is situated in a region overridden by the Southern Patagonian Icefield [...]
Coastal River Response to Transgression: A New Look at the Trinity Incised Valley Using Multi-Resolution Seismic Imaging
Published: 2022-03-29
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Sedimentology
Modern lowland river systems show transitions in flow characteristics near coastlines that lead to systematic changes in sediment deposition and stratigraphic architecture. Sensitivity of fluvial morphodynamics to base-level has important implications for the prediction and interpretation of fluvial stratigraphy, particularly in deposits formed during periods of relative sea-level rise such as [...]
CCC - integrated multiscale study of salt cavern abandonment in the Netherlands
Published: 2022-03-24
Subjects: Geology, Geophysics and Seismology, Materials Science and Engineering, Mineral Physics, Mining Engineering, Other Earth Sciences, Tectonics and Structure
The KEM-17 project of the Dutch State Supervision of Mines presented a critical review of concepts of cavern abandonment and related science. It recommended that analyses of cavern abandonment are done as an integrated project, addressing (i) micro-scale physical processes, (ii) cavern scale models based on field scale experiments and numerical models, (iii) the salt dome scale, to model the far [...]
Geochronology and formal stratigraphy of the Sturtian Glaciation in the Adelaide Superbasin
Published: 2022-03-24
Subjects: Earth Sciences, Geochemistry, Geology, Sedimentology, Stratigraphy
The glaciogenic nature of the Yudnamutana Subgroup was first identified over a century ago, and its global significance was recognised shortly after, eventually culminating with the global Sturtian Glaciation and Snowball Earth theory. Much debate on the origin and timing of these rocks, locally and globally, has ensued in the years since. A significant corpus of research on the lithology, [...]
Late Tonian development and provenance of the Adelaide Superbasin
Published: 2022-03-22
Subjects: Earth Sciences, Geochemistry, Geology, Sedimentology, Stratigraphy, Tectonics and Structure
The late Tonian sequences of the Adelaide Superbasin were witness to the birth of the proto-Pacific Ocean during the breakup of Rodinia. Understanding the sedimentology and provenance of these rocks from across the basin is key to understanding both their deposition over ~70 million years, the local palaeogeography, and leads to a better understanding of the early development of the proto-Pacific [...]
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 [...]