Filtering by Subject: Sedimentology
Published: 2022-09-15
Subjects: Geochemistry, Geology, Sedimentology, Stratigraphy
Cyclostratigraphy and astrochronology are now at the forefront of geologic timekeeping. While this technique heavily relies on the accuracy of astronomical calculations, solar system chaos limits how far back astronomical calculations can be performed with confidence. High-resolution paleoclimate records with Milankovitch imprints now allow reversing the traditional cyclostratigraphic approach: [...]
Published: 2022-08-31
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Paleodischarge estimation is largely undertaken within fluvial settings, and there are limited paleodischarge estimates specifically from delta deposits, despite their significance globally. Making water paleodischarge estimates for deltas using catchment-based approaches developed using data from fluvial settings requires estimation of parameters from the rock record (e.g. paleotemperature, [...]
Published: 2022-08-31
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Quantifying paleodischarge from geological field observations have been for decades, and remains, a key research challenge. Several paleodischarge scaling relationships have been developed for fluvial environments, such as BQART, Fulcrum and regional hydraulic geometry or for river deltas by precluding the role of wave and tide. In deltas where marine (wave, tide) energy causes bidirectional [...]
Published: 2022-08-07
Subjects: Sedimentology, Software Engineering, Stratigraphy
Stratigraphic correlation of geophysical well logs is one of the most important - and most time-consuming - tasks that applied geoscientists perform on a daily basis. Using the dynamic time warping (DTW) algorithm, automated correlation of two wells is a fairly simple task; DTW can also be used to correlate a large number of wells along a single path. However, errors accumulate along a path and [...]
Published: 2022-08-04
Subjects: Geology, Sedimentology, Tectonics and Structure
Deformation on shale-rich continental margins is commonly associated with thin-skinned extension above mobile shales. Normal faulting and shale mobilization are widespread on such margins, being associated with and controlled by progradation and gravitational failure of deltaic sedimentary wedges. However, due to limitations in our ability to seismically imaging these mobile shales, our [...]
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 [...]
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 laterally-stacked, high-amalgamation (HA) channels, and floodplain-dominated intervals with vertically-stacked, low-amalgamation (LA) channels. Such patterns are usually ascribed to slow and high rates of base-level rise respectively, but “upstream” factors such as [...]
Published: 2022-07-25
Subjects: Biogeochemistry, Environmental Sciences, Geochemistry, Sedimentology
Laminated sediments can record seasonal changes in sedimentation of material from anoxic waters, including minerals of the redox-sensitive elements Fe, Mn, and S that form under varying oxygen levels, mineral saturation conditions, and from microbial metabolism. However, preserving both the oxygen-sensitive minerals for identification is challenging when preservation of the spatial arrangement of [...]
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 [...]
Published: 2022-05-29
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, [...]
Published: 2022-05-29
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 ~3.6 Myr lacustrine carbonate carbon and oxygen stable isotope record from a Great Basin continental drill core. We pair these measurements with bulk lithium concentrations to reveal a relationship between past climate and lithium enrichment in authigenic [...]
Published: 2022-05-27
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 [...]
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 [...]
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 [...]
Published: 2022-04-20
Subjects: Computational Engineering, Sedimentology
Microfossil fish teeth, known as ichthyoliths, provide a key constraint on the depositional age and environment of deep-sea sediments, especially pelagic clays where siliceous and calcareous microfossils are rarely observed. However, traditional methods for the observation of ichthyoliths require considerable time and manual labor, which can hinder their wider application. In this study, we [...]