Sediment-routing controls on sandstone bulk petrographic composition and texture across an ancient shelf: Example from Cretaceous Western Interior Basin, Utah and Colorado, U.S.A.

2020 ◽  
Vol 90 (10) ◽  
pp. 1389-1409
Author(s):  
Janifar H. Lupin ◽  
Gary J. Hampson
Keyword(s):  
Grain Size ◽  
Thin Section ◽  
Sediment Supply ◽  
Maximum Diameter ◽  
Sand Transport ◽  
Petrographic Composition ◽  
Sediment Routing ◽  
Mean Grain Size ◽  
Western Interior Basin ◽  
Change In Mean

ABSTRACT Sediment-routing controls on sandstone texture and bulk petrography have been evaluated in linked alluvial–coastal–shelfal deposits of the Upper Cretaceous Castlegate Sandstone, Blackhawk Formation, Star Point Sandstone, and Mancos Shale (Western Interior Basin, Utah and Colorado, USA) using thin-section analysis of representative outcrop samples in the context of a high-resolution sequence stratigraphic and paleogeographic framework. The studied strata record deposition from two styles of sediment-routing system within an overfilled foredeep and contiguous intra-continental seaway. First, multiple transverse drainages supplied sand to fluvial, shoreline, and shelf segments of sediment-routing systems characterized by down-dip transport distances of 150–450 km and significant strike-oriented sediment transport along the shoreline. Second, the distal shoreline–shelf segment of an axially supplied sediment-routing system was characterized by sand transport for a distance of c. 300 km. Bulk petrographic composition indicates that transverse sediment-routing systems were sourced from catchments that supplied quartz-rich sand with a subordinate lithic component, while the large axial sediment-routing system was sourced from a catchment(s) supplying slightly more feldspathic sand. Thin-section measurements of mean grain size, sorting, skewness, and ratio of minimum-to-maximum diameter (a proxy for sphericity) are similar for sandstones deposited in fluvial, shoreline, and shelf segments of the transverse sediment-routing systems and in the shoreline–shelf segment of the axial sediment-routing systems, although hydrodynamic sorting is important in locally segregating grain-size populations within each segment. Further, textural analysis of detrital quartz, feldspar, and lithic sand-grain populations shows little evidence of relative change in mean grain size or apparent grain sphericity with downsystem distance, implying that sand-grain populations of different petrographic composition did not undergo significant differential mechanical breakdown during transport. Instead, the textural characteristics of these sand-grain populations are inferred to have been controlled mainly by bedrock lithology and recycling in source catchments. The textural signal of sediment-source areas then propagated downsystem in the sand fraction of detrital sediment supply. This inference is supported by the fine- to medium-grained, well- to very well-sorted character of all sandstone samples, consistent with recycling of sandstones and quartzites from the Sevier fold-and-thrust belt.

Upstream versus downstream changes in a natural sediment routing system from source to sink

2020 ◽  
Author(s):  
Nikhil Sharma ◽  
Jean Vérité ◽  
Stephen Watkins ◽  
Luis Valero ◽  
Alex Whittaker ◽  
...  
Keyword(s):  
Grain Size ◽  
Middle Eocene ◽  
Flow Direction ◽  
Water Discharge ◽  
3D Models ◽  
Sediment Supply ◽  
Aerial Photographs ◽  
Natural Sediment ◽  
Sediment Routing ◽  
South Central

<p>The Middle Eocene Climatic Optimum (MECO) represents an episode of widespread warming occurring ~40 million years ago. It is characterized by gradual warming over a period of 500,000 years, leading to a rise in ocean temperatures of about 5° C in the mid and high-latitudes (Sluijs et al., 2013). Contrary to the traditional understanding and consensus that accommodation space or downstream factors control stratigraphic architecture in fluvial successions, we test the hypothesis that upstream factors, rather than downstream factors, control fluvial architecture through changes in the median grain size, sediment supply and water discharge with paleoslope being a measurable proxy to quantify these changes. We test our hypothesis utilizing the natural system of the Escanilla sediment routing system, encompassing the Middle Eocene Climatic Optimum. The Escanilla system is an overall prograding system, consisting of 1000 m thick alluvial and fluvial deposits at the southern-margin of the Tremp-Graus Basin in the south/central Pyrenees, Spain. Multiple lateral measurements for grain size distributions and cross-set measurements, flow direction and channel geometry are taken close to the source (Coll de Vent), at an intermediate location (Lascuarre), and at a distal part (Olson) of the system for paleohydraulic reconstructions. Drone flight missions are also undertaken to capture aerial photographs of the field area, which are required for the construction of 3D photogrammetric models. At Olson, alternating sequences of laterally continuous amalgamated channel bodies and several small sequences of vertically stacked isolated channel bodies have been identified. Preliminary results show distinct values of median grain size, dune height, flow depth and paleoslope for the amalgamated and vertically stacked isolated channel sequences across the MECO; the addition of our 3D models provide further insight into the lateral connectivity of the amalgamated units. Our results suggest different paleohydraulic conditions during the deposition of amalgamated and nonamalgamated units. This data will also be supported by numerical simulations carried out to better understand the response of fluvial systems to changes in upstream factors.</p>

Sedimentological and Biological Changes Associated with the Construction of the Oil Terminal of Antifer, France

1984 ◽  
Vol 16 (3-4) ◽  
pp. 399-406
Author(s):  
Y Monbet
Keyword(s):  
Grain Size ◽  
Environmental Changes ◽  
Biological Effects ◽  
Standing Stock ◽  
Natural Populations ◽  
Benthic Fauna ◽  
Field Investigations ◽  
Mean Grain Size ◽  
To Receive ◽  
Principal Species

A study was conducted to gain insight on actual sedimentological and biological effects associated with the construction of an oil Terminal designed to receive 500 000 d.w.t. tankers. Field investigations and subsequent laboratory analyses were organized to evaluate the nature and magnitude of environmental changes on benthic macrofauna, three years after the end of the construction. Sediments were found to decrease dramatically in medium grain size in area sheltered by the newly built breakwater. Increase of percentage of silt and clays (90 % against 20 %) was observed leeward of the jetty. The benthic fauna showed significant modifications. Although the same community (Pectinaria kareni Abra alba) recolonized the bottom after the dredging of up to 30 × 106 m3 of sediments, increase in abundance occured. Biomass remained at a constant level and decrease of diversity was observed. Considering the rate of siltation, and assuming a constant siltation rate equal to the rate observed from 1975 to 1978, a simple regressive model relating biomass to mean grain size of sediments has been developped. This model allowed the prediction of biomass and production of the two principal species for the period 1978 – 1981. Continuous siltation within the harbor leads to a maximum of biomass from years after the end of the construction, followed by a decrease of standing stock. This process may be explained by the respective tolerance of the two principal species to increase silt contant and also probably by the accumulation of organic matter which may impede the development of natural populations.

scholarly journals Preparation of high-entropy carbides by different sintering techniques

2021 ◽  
Vol 56 (19) ◽  
pp. 11237-11247 ◽  
Author(s):  
Johannes Pötschke ◽  
Manisha Dahal ◽  
Mathias Herrmann ◽  
Anne Vornberger ◽  
Björn Matthey ◽  
...  
Keyword(s):  
Grain Size ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Vacuum Sintering ◽  
X Ray ◽  
High Entropy ◽  
Mean Grain Size ◽  
The Mean ◽  
Gas Pressure Sintering ◽  
Hardness Values

AbstractDense (Hf, Ta, Nb, Ti, V)C- and (Ta, Nb, Ti, V, W)C-based high-entropy carbides (HEC) were produced by three different sintering techniques: gas pressure sintering/sinter–HIP at 1900 °C and 100 bar Ar, vacuum sintering at 2250 °C and 0.001 bar as well as SPS/FAST at 2000 °C and 60 MPa pressure. The relative density varied from 97.9 to 100%, with SPS producing 100% dense samples with both compositions. Grain size measurements showed that the substitution of Hf with W leads to an increase in the mean grain size of 5–10 times the size of the (Hf, Ta, Nb, Ti, V,)C samples. Vacuum-sintered samples showed uniform grain size distribution regardless of composition. EDS mapping revealed the formation of a solid solution with no intermetallic phases or element clustering. X-ray diffraction analysis showed the structure of mostly single-phase cubic high-entropy carbides. Hardness measurements revealed that (Hf, Ta, Nb, Ti, V)C samples possess higher hardness values than (Ta, Nb, Ti, V, W)C samples.

Holocene sedimentation in the Hupo Trough of the southwestern East Sea (Japan Sea) and development of the East Korea Warm Current

The Holocene ◽  
2021 ◽  
pp. 095968362110032
Author(s):  
Boo-Keun Khim ◽  
Sunghan Kim ◽  
Yu-Hyeon Park ◽  
Jongmin Lee ◽  
Sangbeom Ha ◽  
...  
Keyword(s):  
Grain Size ◽  
Japan Sea ◽  
East Sea ◽  
Eastern Coast ◽  
Size Change ◽  
Sediment Properties ◽  
Warm Current ◽  
The Holocene ◽  
Mean Grain Size ◽  
East Korea Warm Current

Various sediment properties, such as mean grain size, total organic carbon, total nitrogen, C/N ratio, CaCO3, and biogenic opal content, were analyzed for a box core (BC02; 45 cm long) and a gravity core (GC02; 628 cm long), which were collected from the western margin of the Hupo Trough located off the eastern coast of Korea. The study area has been affected by the East Korea Warm Current (EKWC), a branch of the Tsushima Warm Current (TWC). The analytical results obtained for BC02 and the upper part of GC02 were in agreement, affirming the core-top preservation of GC02. Based on the corrected calibrated AMS 14C dates, the sedimentation rate of GC02 changed abruptly at ~8.2 ka from ~4.0–10.2 cm/kyr in the lower part to ~56.6–91.0 cm/kyr in the middle to upper part. This corresponds to the lithologic change from sandy mud to mud sediments showing the mean grain size change from 6.9 to 46.0 μm. Diverse paleoceanographic proxies representing the surface water condition exhibited varying degree of change at ~8.2 ka, after which all the properties remain almost unchanged, implying stable and continuous depositional conditions following the complete development of the EKWC. Furthermore, it indicated that the sediment depositional conditions in the Hupo Trough in response to the EKWC might have stabilized at ~8.2 ka since the opening of the Korea Strait during the Holocene sea level rise. Moreover, microfossil data from previous studies on the establishment of the TWC in the East Sea (Japan Sea) support our interpretation that the sediment properties revealed the Holocene development of the EKWC in the Hupo Trough.

The Use of Closely Spaced Vickers Indentations to Model Erosion of Polycrystalline α-Al2O3

2004 ◽  
Vol 843 ◽  
Author(s):  
Adolfo Franco Júnior ◽  
Steve G. Roberts
Keyword(s):  
Grain Size ◽  
Impact Velocity ◽  
Erosive Wear ◽  
Significant Loss ◽  
Crack Coalescence ◽  
Good Correspondence ◽  
Mean Grain Size ◽  
Static Indentation ◽  
Α Al2o3 ◽  
Wear Maps

ABSTRACTArrays of closely spaced quasi-static indentation were made on specimens of polycrystalline α-Al2O3, mean grain size G=1.2, 3.8 and 14.1 μm. The critical indentation spacing to produce crack coalescence between indentations, and thus significant loss of material from the surface, was determined. These data are compared to results for low-impact-velocity wet erosive wear on the same materials; a good correspondence is found. The indentation data can be used to produce “wear maps”, which provide a guideline for predicting the low-impact-velocity erosive wear resistance of brittle materials.

scholarly journals Fabrication of (SiC-AlN)/ZrB2 Composite with Nano-Micron Hybrid Microstructure via PCS-Derived Ceramics Route

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 334
Author(s):  
Aidong Xia ◽  
Jie Yin ◽  
Xiao Chen ◽  
Zhengren Huang ◽  
Xuejian Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Raw Materials ◽  
Secondary Phase ◽  
Pressing Temperature ◽  
Xrd Pattern ◽  
Mean Grain Size ◽  
The Mean

In this work, a (SiC-AlN)/ZrB2 composite with outstanding mechanical properties was prepared by using polymer-derived ceramics (PDCs) and hot-pressing technique. Flexural strength reached up to 460 ± 41 MPa, while AlN and ZrB2 contents were 10 wt%, and 15 wt%, respectively, under a hot-pressing temperature of 2000 °C. XRD pattern-evidenced SiC generated by pyrolysis of polycarbosilane (PCS) was mainly composed by 2H-SiC and 4H-SiC, both belonging to α-SiC. Micron-level ZrB2 secondary phase was observed inside the (SiC-AlN)/ZrB2 composite, while the mean grain size (MGS) of SiC-AlN matrix was approximately 97 nm. This unique nano-micron hybrid microstructure enhanced the mechanical properties. The present investigation provided a feasible tactic for strengthening ceramics from PDCs raw materials.

Modeling shelter abundance for juvenile Atlantic salmon in a residual flow reach of a hydro power plant using SSIIM 2

2021 ◽  
Author(s):  
Spyros Pritsis ◽  
Nils Ruther ◽  
Kordula Schwarzwälder ◽  
Anastasios Stamou
Keyword(s):  
Grain Size ◽  
Atlantic Salmon ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Sediment Supply ◽  
Substrate Composition ◽  
Juvenile Atlantic Salmon ◽  
River Reach ◽  
Bed Changes ◽  
Shelter Availability

<p>Nowadays, the aquatic biodiversity is highly under pressure due to anthropogenic changes of the rivers such hydraulic structures changing the diversity of flow and aquatic fauna as well as sediment continuity. This can have severe consequences on the fish population in the river reach. Fish are strongly depending on a certain substrate composition throughout all their life stages. Juveniles for example are depending on a certain availability of shelter in the substrate in order to survive this stage.</p><p>Therefore, we investigate the effects of changes in the sediment composition at a hydropower plant in Switzerland on the availability of potential shelter for juvenile fish. By utilizing the observed correlation between parameters describing the fine tail of a riverbed’s grain size distribution and shelter abundance for juvenile Atlantic salmon, we predict the available shelter in a river reach by using a 3D hydrodynamic numerical model directly coupled to a morphodynamic model. The initial substrate composition was assumed to be spatially uniform, its parameters based on a grain size distribution curve derived from collected sediment samples.</p><p>This model can now be used for habitat improvement scenario modeling. Based on the assumption that a specific mixture of sediment coming from upstream travelling through the river reach will positively influence the potential shelter availability, different scenarios can be investigated. The baseline for comparison was the simulation of the bed changes without any sediment supply from upstream. The baseline discharge was set to 100 m<sup>3</sup> /s and was applied for 24 hours. The resulting bed changes create a map of the potential shelter availability of this grain size mixture. Then, two scenarios with sediment inflow from the upstream boundary were simulated. One coarse and one fine mixture of sediment were chosen as inputs, with the goal of investigating their impact on shelter abundance. The former designed to have a positive effect while the latter expected to reduce interstitial voids in the substrate and have a negative effect on available shelter.</p><p>The investigation is conducted as part of the EU Horizon 2020 funded project FIThydro (funded under 727830)</p>

The Study on the Fabrication of Nano-Structured Steel by Cold Rolling and Annealing of Martensite

2013 ◽  
Vol 634-638 ◽  
pp. 1807-1810
Author(s):  
Guang Xu ◽  
Jing Yang ◽  
Tao Xiong ◽  
Peng Deng ◽  
Long Fei Cao
Keyword(s):  
Grain Size ◽  
Cold Rolling ◽  
High Strength ◽  
Total Elongation ◽  
Plain Carbon Steel ◽  
Mean Grain Size ◽  
Cold Rolling And Annealing ◽  
The Mean ◽  
Martensite Microstructure ◽  
Very High

Sub-nano structured steel was obtained by cold rolling and annealing martensite microstructure for a plain carbon steel. The mean grain size is several hundreds nanometer. The steel has very high strength and also good total elongation.

Sediment slugs: large-scale fluctuations in fluvial sediment transport rates and storage volumes

1995 ◽  
Vol 19 (4) ◽  
pp. 500-519 ◽  
Author(s):  
A.P. Nicholas ◽  
P.J. Ashworth ◽  
M.J. Kirkby ◽  
M.G. Macklin ◽  
T. Murray
Keyword(s):  
Sediment Transport ◽  
Sediment Supply ◽  
Fluvial Systems ◽  
Event Scale ◽  
Fluvial Sediment ◽  
Sediment Routing ◽  
Basin Scale ◽  
Wide Range ◽  
And Storage ◽  
Fluvial Sediment Transport

Variations in fluvial sediment transport rates and storage volumes have been described previously as sediment waves or pulses. These features have been identified over a wide range of temporal and spatial scales and have been categorized using existing bedform classifications. Here we describe the factors controlling the generation and propagation of what we term sediment slugs. These can be defined as bodies of clastic material associated with disequilibrium conditions in fluvial systems over time periods above the event scale. Slugs range in magnitude from unit bars (Smith, 1974) up to sedimentary features generated by basin-scale sediment supply disturbances (Trimble, 1981). At lower slug magnitudes, perturbations in sediment transport are generated by local riverbank and/or bed erosion. Larger-scale features result from the occurrence of rare high- magnitude geomorphic events, and the impacts on water and sediment production of tectonics, glaciation, climate change and anthropogenic influences. Simple sediment routing functions are presented which may be used to describe the propagation of sediment slugs in fluvial systems. Attention is drawn to components of the fluvial system where future research is urgently required to improve our quantitative understanding of drainage-basin sediment dynamics.

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