Preprints
Filtering by Subject: Sedimentology
The impact of Holocene deglaciation and glacial dynamics on the landscapes and geomorphology of Potter Peninsula, King George Island (Isla 25 Mayo), NW Antarctic Peninsula
Published: 2022-10-19
Subjects: Earth Sciences, Geology, Geomorphology, Glaciology, Physical Sciences and Mathematics, Sedimentology
The timing and impact of deglaciation and Holocene readvances on the terrestrial continental margins of the Antarctic Peninsula have been well-studied but are still debated. Potter Peninsula on King George Island (Isla 25 de Mayo), South Shetland Islands (SSI), NW Antarctic Peninsula has a detailed assemblage of glacial landforms and stratigraphic exposures for constraining deglacial landscape [...]
Geochemical mapping by unmixing alluvial sediments: An example from northern Australia
Published: 2022-10-01
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Geochemistry, Geomorphology, Natural Resource Economics, Sedimentology, Soil Science, Water Resource Management
Alluvial sediments have long been used in geochemical surveys as their compositions are assumed to be representative of areas upstream. Overbank and floodplain sediments, in particular, are increasingly used for regional to continental-scale geochemical mapping. However, during downstream transport, sediments from heterogeneous source regions are carried away from their source regions and mixed. [...]
North Atlantic Drift Sediments Constrain Eocene Tidal Dissipation and the Evolution of the Earth-Moon System
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: [...]
Down-delta hydraulic geometry and its application to the rock record
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, [...]
Practical sampling criteria for using delta channel width to estimate paleodischarge in the rock record
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 [...]
Automated stratigraphic correlation and model building using chronostratigraphic principles
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 [...]
Extensional Deformation of a Shale-dominated Delta: Tarakan Basin, Offshore Indonesia
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 [...]
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 [...]
Evaluation of preservation protocols for oxygen-sensitive minerals within laminated aquatic sediments
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 [...]
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 [...]
Diagenetic priming of submarine landslides in ooze-rich substrates
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, [...]
Paleoclimate controls on lithium enrichment in Great Basin Pliocene-Pleistocene lacustrine clays
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 ∼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: 2022-05-27
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 [...]
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 [...]