Preprints
Filtering by Subject: Geology
Influence of reef isostasy, dynamic topography, and glacial isostatic adjustment on sea-level records in Northeastern Australia
Published: 2022-08-05
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics
Understanding sea level during the warmest peak of the Last Interglacial (125,000 yrs ago; Marine Isotope Stage 5e) is important for assessing future ice-sheet dynamics in response to climate change, and relies on the measurement and interpretation of paleo sea-level indicators, corrected for post-depositional vertical land motions. The coasts and continental shelves of northeastern Australia [...]
Mud redeposition during river incision as a factor affecting authigenic 10Be/9Be dating: Early Pleistocene large mammal fossil-bearing site Nová Vieska, eastern Danube Basin
Published: 2022-07-29
Subjects: Earth Sciences, Geology, Geomorphology, Sedimentology, Stratigraphy
This study examines the suitability of the authigenic 10Be/9Be dating method to the dating of the deposits of an incising river, taking as an example the Nová Vieska river terrace, which accumulated during the neotectonic inversion of the Danube Basin (western Slovakia). The succession was formed by a wandering river with minor preservation of proximal floodplain muds. The frequent occurrence of [...]
Water discharge variations control fluvial stratigraphic architecture in the Middle Eocene Escanilla formation, Spain
Published: 2022-07-27
Subjects: Earth Sciences, Geology, Geomorphology, Hydrology, Sedimentology, Stratigraphy
Ancient fluvial deposits typically display repetitive changes in their depositional architecture such as alternating intervals of coarse-grained highly amalgamated (HA), laterally-stacked, channel bodies, and finer-grained less amalgamated (LA), vertically-stacked, channels encased in floodplain deposits. Such patterns are usually ascribed to slower, respectively higher, rates of base level rise [...]
Barren ground depressions, natural H2 and orogenic gold deposits: spatial link and geochemical model
Published: 2022-07-11
Subjects: Earth Sciences, Ecology and Evolutionary Biology, Geochemistry, Geology, Geomorphology, Soil Science
A review of the localities in continental rocks where H2-rich gases have been reported, showed that they are mainly located near gold deposits. Two types of geomorphological features known as markers of gas venting in sedimentary basins were also systematically observed near orogenic gold deposits on satellite images. They consist in both barren ground depressions and high densities of small (< [...]
The Eighth Wonder of the World in New Zealand─ the third, Black Terrace
Published: 2022-06-29
Subjects: Geology, Geomorphology, Other Earth Sciences, Other Environmental Sciences, Other Planetary Sciences, Stratigraphy, Volcanology
The greatest tourism and geoscience attraction in the southern hemisphere, in the nineteenth century were the siliceous Pink and White Terraces, the lost Eighth Wonder of the World in New Zealand. In 1886, the Mount Tarawera eruption buried the terraces. In the absence of any government survey or evidence of their locations or destruction; debate over their survival continued until the 1940s. [...]
Controls on grain size distribution in an ancient sand sea
Published: 2022-06-25
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
Grain size distribution in deserts is driven by a combination of autogenic controls such as grain abrasion and sorting due to wind transport and allogenic controls such as provenance and spatial changes in wind-direction. Downwind grain-size trends in present day sand seas display contrasting results. For example, the Namib and Hexi Corridor sand seas show broad downwind fining and sorting [...]
Pervasive carbonation of peridotite to listvenite (Semail Ophiolite, Sultanate of Oman): clues from iron partitioning and chemical zoning
Published: 2022-06-22
Subjects: Geochemistry, Geology
Earth’s long-term cycling of carbon is regulated from mid-ocean ridges to convergent margins by mass transfers involving mantle rocks. Here we examine the conversion of peridotite into listvenite (magnesite+quartz) occurring along the basal thrust of the Semail Ophiolite (Fanja, Sultanate of Oman). At the outcrop scale, this transformation defines reaction fronts, from serpentinized peridotites, [...]
Ascent rates of 3D fractures driven by a finite batch of buoyant fluid
Published: 2022-06-20
Subjects: Fluid Dynamics, Geology, Glaciology, Mechanics of Materials, Volcanology
Propagation of fluid-filled fractures by fluid buoyancy is important in a variety of settings, from magmatic dykes and veins to water-filled crevasses in glaciers. Industrial hydro-fracturing utilises fluid-driven fractures to increase the permeability of rock formations, but few studies have quantified the effect of buoyancy on fracture pathways in this context. Analytical approximations for the [...]
Friction law for earthquake nucleation: size doesn’t matter
Published: 2022-06-17
Subjects: Geology, Geophysics and Seismology
A central question in modeling induced and natural earthquake nucleation is whether fault frictional properties measured in the laboratory are applicable to nature. A laboratory fault is generally just a few centimeters in length-width scale, while natural faults can be hundreds of meters to kilometers in extent. It is unknown whether laboratory fault friction data are applicable even to mesh [...]
Understanding Sampling Bias in the Global Heat Flow Compilation
Published: 2022-06-17
Subjects: Databases and Information Systems, Earth Sciences, Geology, Tectonics and Structure
Geothermal heat flow is commonly inferred from the gradient of temperature values in boreholes. Such measurements are expensive and logistically challenging in remote locations and, therefore, often targeted to regions of economic interest. As a result, measurements are not distributed evenly. Some tectonic, geologic and even topographic settings are overrepresented in global heat flow [...]
Diagenetic priming of submarine landslides in ooze-rich substrates
Published: 2022-05-30
Subjects: Earth Sciences, Geology, Sedimentology
Oozes are the most widespread deep-sea sediment in the global ocean, but very little is known about how changes in their physical properties during burial impact slope stability and related geohazards. Here, we use 3D seismic reflection, geochemical, and petrophysical data acquired both within and adjacent to 13 large (in total c. 6330 km2) submarine slides on the Exmouth Plateau, NW Shelf, [...]
Paleoclimate controls on lithium enrichment in Great Basin Pliocene-Pleistocene lacustrine clays
Published: 2022-05-30
Subjects: Climate, Earth Sciences, Environmental Sciences, Geochemistry, Geology, Natural Resources and Conservation, Other Environmental Sciences, Sedimentology
Terminal lakes are important archives of continental hydroclimate and in some cases contain important economic resources. Here, we present an ∼2.9 m.y. lacustrine carbonate carbon and oxygen stable isotope record from a Great Basin continental drill core. We paired these measurements with bulk lithium concentrations to reveal a relationship between past climate and lithium enrichment in [...]
How to drain a megalake: Comments on a study by Palcu et al. (2021) Scientific Reports 11, Art. Nr.: 11471.
Published: 2022-05-28
Subjects: Earth Sciences, Geology, Oceanography, Paleobiology, Paleontology, Sedimentology, Stratigraphy, Tectonics and Structure
In a recent paper by Palcu et al. (2021: Scientific Reports 11, Art. Nr.: 11471), the Cape Panagia section on the Taman peninsula (Russian Black Sea) was dated using magnetostratigraphy, in order to calibrate the timing of previously published regressions of the Paratethys megalake. The authors of the paper claim that this “largest megalake in the geological record” experienced four major [...]
Salt-detached strike-slip faulting, Outer Kwanza Basin, Offshore Angola
Published: 2022-05-26
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: 2022-05-20
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 [...]