Filtering by Subject: Sedimentology
Published: 2021-04-20
Subjects: Geology, Sedimentology
This study investigates the Provenance of the Barremian-Aptian fluvial clastics exposed in the Essaouira-Agadir Basin which bears an important potential in terms of offshore feeding of reservoir sands. Thin section petrography and SEM, heavy minerals analysis, and detrital zircon dating were conducted and integrated with a large dataset of published low-temperature thermochronology studies to [...]
Published: 2021-04-15
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Geophysics and Seismology, Geotechnical Engineering, Physical Sciences and Mathematics, Sedimentology
The orientation of and contacts between grains of sand reflect the processes that deposit the sands. Grain orientation and contact geometry also influence mechanical properties. Quantifying and understanding sand microstructure thus provide an opportunity to understand depositional processes better and connect microstructure and macroscopic properties. We compare naturally-deposited beach sands [...]
Published: 2021-04-07
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology
Submarine canyons incise continental shelves and slopes, and are important conduits for the transport of sediment, nutrients, organic carbon and pollutants from continents to oceans. Submarine canyons bear morphological similarities to subaerial valleys, such as their longitudinal (long) profiles. Long profiles record the interaction between erosion and uplift, making their shape, or concavity, a [...]
Published: 2021-03-19
Subjects: Biogeochemistry, Geology, Paleobiology, Plant Sciences, Research Methods in Life Sciences, Sedimentology, Soil Science
Correlative imaging provides a method of investigating complex systems by combining analytical (chemistry) and imaging (tomography) information across dimensions (2D-3D) and scales (centimetres-nanometres). We studied weathering processes in a modern cryptogamic ground cover (CGC) from Iceland, containing early colonizing, and evolutionary ancient, communities of mosses, lichens, fungi, and [...]
Published: 2021-03-18
Subjects: Earth Sciences, Geology, Sedimentology, Stratigraphy, Tectonics and Structure
The Plio-Pleistocene Lichi Mélange in the Coastal Range of eastern Taiwan offers an excellent opportunity to study processes of mélange development at the continent-ocean interface of an active arc-continent collision. This paper presents new results of detailed geologic mapping, lithofacies analysis, magneto-biostratigraphy, paleocurrent, and paleoslope analyses in the southern Coastal Range to [...]
Published: 2021-03-17
Subjects: Earth Sciences, Geochemistry, Geology, Sedimentology, Stratigraphy
Stable carbon isotope curves are used as a precise stratigraphic tool in the Paleozoic, even though they are commonly based on shallow-water carbonate record, characterized by low stratigraphic completeness. Identification of episodes of large-scale redeposition and erosion may improve δ13Ccarb-based correlations. Here, a series of at least three episodes of high-energy onshore redeposition are [...]
Published: 2021-03-17
Subjects: Earth Sciences, Geology, Geomorphology, Paleontology, Sedimentology, Stratigraphy, Tectonics and Structure
The occurrence of km-scale exhumations during syn- and post-rift stages has been documented along Atlantic continental margins, which are also characterised by basins undergoing substantial subsidence. The relationship between the exhuming and subsiding domains is poorly understood. In this study, we reconstruct the evolution of a 50 km long transect across the Moroccan rifted margin from the [...]
Published: 2021-03-12
Subjects: Earth Sciences, Geochemistry, Geology, Sedimentology, Stratigraphy
The Trezona carbon isotope excursion is recorded on five different continents in platform carbonates deposited prior to the end-Cryogenian Marinoan glaciation (>635 Ma) and represents a change in carbon isotope values of 16-18 per mill. Based on the spatial and temporal reproducibility, the excursion previously has been interpreted as tracking the carbon isotopic composition of dissolved [...]
Published: 2021-03-01
Subjects: Climate, Earth Sciences, Geology, Geomorphology, Hydrology, Longitudinal Data Analysis and Time Series, Other Earth Sciences, Sedimentology, Statistical Methodology, Stratigraphy
Changes in lake status are often interpreted as palaeoclimate indicators due to their dependence on precipitation and evaporation. The Global Lake Status Database (GLSDB) has since long provided a standardised synopsis of qualitative lake status over the last 30,000 14C years. Potential sources of uncertainty however are not recorded in the GLSDB. Here we present an updated and improved [...]
Published: 2021-02-26
Subjects: Earth Sciences, Geology, Paleobiology, Paleontology, Sedimentology, Stratigraphy
Stratigraphic changes in the clustering of first or last taxon occurrences are a joint expression of evolutionary, ecological, taphonomic, and sedimentological processes. Sedimentation rates control the degree of sedimentary dilution and condensation and thus alter the time contained in a given thickness of sediment. However, it remains poorly explored quantitatively how distinct the [...]
Published: 2021-02-25
Subjects: Climate, Earth Sciences, Geology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Paleontology, Sedimentology, Stratigraphy
This study proposes that sandstone layers exposed in the Fez-Meknes region of Northern Morocco (Ben Allou (Sidi Chaded) and El Adergha localities), have been misinterpreted as unique examples of geostrophically-driven, deep marine (150 - 400 m water depth) sandy contourites. Instead, our independent paleontological, sedimentological, and stratigraphic analyses show that these sandstones represent [...]
Published: 2021-02-15
Subjects: Earth Sciences, Geology, Geomorphology, Sedimentology, Stratigraphy, Tectonics and Structure
The area of the Offshore NW Sulawesi lies between eastern Sundaland (Borneo) and the North Arm of Sulawesi. Possible influences on the basins include Paleogene rifting in the Celebes Sea and Makassar Strait, Neogene subsidence and uplift in Borneo, late Neogene subduction at the present-day North Sulawesi Trench, and displacements related to the Palu-Koro Fault. This study presents the results of [...]
Published: 2021-02-14
Subjects: Civil and Environmental Engineering, Computer Sciences, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Geology, Geomorphology, Glaciology, Hydrology, Numerical Analysis and Scientific Computing, Other Environmental Sciences, Physical Sciences and Mathematics, Sedimentology, Soil Science, Stratigraphy
Computational modelling occupies a unique niche in Earth environmental sciences. Models serve not just as scientific technology and infrastructure, but also as digital containers of the scientific community's understanding of the natural world. As this understanding improves, so too must the associated software. This dual nature---models as both infrastructure and hypotheses---means that [...]
Published: 2021-02-02
Subjects: Biogeochemistry, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Multivariate Analysis, Oil, Gas, and Energy, Other Earth Sciences, Paleobiology, Paleontology, Sedimentology
Ordination is the name given to a group of methods used to analyze multiple variables without preceding hypotheses. Over the last few decades the use of these methods in Earth science in general, and notably in analyses of sedimentary sources, has dramatically increased. However, with limited resources oriented towards Earth scientists on the topic, the application of ordination analysis is at [...]
Published: 2021-01-29
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Geomorphology, Hydraulic Engineering, Physical Sciences and Mathematics, Sedimentology
Upper Mississippi River flow and sediment characteristics downstream of St. Louis are presented in this study. Available and measured data were used to assess a harbor siltation case and dredging needs. Such data are also useful to researchers and engineers conducting work in the Mississippi River and large rivers in general. Flows were characterized in terms of the mean annual hydrograph, flow [...]