Complex permittivity and clay mineralogy of grain-size fractions in a wet silt soil

Geophysics ◽  
2008 ◽  
Vol 73 (3) ◽  
pp. J1-J13 ◽  
Author(s):  
Steven Arcone ◽  
Steven Grant ◽  
Ginger Boitnott ◽  
Benjamin Bostick
Keyword(s):  
Grain Size ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Complex Permittivity ◽  
Mineral Content ◽  
Size Fraction ◽  
Clay Mineralogy ◽  
Free Water ◽  
Size Fractions ◽  
Grain Size Fractions

We determined the complex permittivity and clay mineralogy of grain-size fractions in a wet silt soil. We used one clay-size fraction and three silt-size fractions, measured permittivity with low error from [Formula: see text] with time-domain spectroscopy, and estimated mineral weight percentages using X-ray diffraction (XRD). The volumetric water contents were near 30%, and the temperature was [Formula: see text]. For the whole soil, standard fractionation procedures yielded 2.4% clay-size particles by weight, but XRD showed that the phyllosilicate clay minerals kaolinite, illite, and smectite made up 17% and were significantly present in all fractions. Above approximately [Formula: see text], all real parts were similar. Below approximately [Formula: see text], the real and imaginary permittivities increased with decreasing grain size as frequency decreased, and the imaginary parts became dominated by direct-current conduction. Similarly, below approximately [Formula: see text], the measured permittivity of montmorillonite, a common smectite, dominated that of the other clay minerals. Total clay mineral and smectite mass fractions consistently increased with decreasing grain size. Below [Formula: see text], a model with progressively increasing amounts of water and parameters characteristic of montmorillonite matches the data well for all fractions, predicts permittivities characteristic of free water in smectite structural galleries, and shows that the similar real parts above [Formula: see text] are caused by a small suppression of the high-frequency static value of water permittivity by the smectite. We conclude that the clay mineral content, particularly smectite, appears to be responsible for permittivity variations between grain-size fractions. Small model mismatches in real permittivity near the low-frequency end and the greater fractions of kaolinite and illite suggest that the total clay mineral content might have been important for the coarser fractions.

A mineralogical and geochemical study of turbidite sandstones and interbedded shales, Mam Tor, Derbyshire, UK

Clay Minerals ◽  
1981 ◽  
Vol 16 (4) ◽  
pp. 333-345 ◽  
Author(s):  
D.A. Spears ◽  
M.A. Amin
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Clay Mineral ◽  
Mixed Layer ◽  
Clay Mineralogy ◽  
Lateral Variation ◽  
Size Fractions ◽  
Shore Line ◽  
Geochemical Study ◽  
Size Sorting

AbstractEleven shales and fourteen turbidite sandstones from the Mam Tor Beds were analysed chemically and by XRD. The ratio of kaolinite to illite plus mixed-layer clay was higher in the sandstones than in the shales, size fractions demonstrating that this ratio decreased as the grain size decreased. Shales more basinal in character than those of the Mam Tor Beds contain more illite and mixed-layer clay and less kaolinite and it is suggested that there was a lateral variation in clay mineralogy with distance from the shore line due to particle size sorting and that the character of the clay mineral fraction was retained as the turbidity current transported sediment from a nearshore environment deeper into the basin. Support for this model was obtained from the geochemistry which showed that the sandstone matrix differed compositionally from the shales. Systematic variations occurred in the turbidite sandstones but not in the shales which are therefore considered to be non-turbiditic. Only minor mineralogical changes appear to have occurred during diagenesis.

scholarly journals Quantitative clay mineralogy as a tool for lithostratigraphy of Neogene Formations in Belgium: a reconnaissance study

2020 ◽  
Vol 23 (3-4) ◽  
Author(s):  
Rieko ADRIAENS ◽  
Noël VANDENBERGHE
Keyword(s):  
Detailed Analysis ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Natural Radioactivity ◽  
Mineral Content ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Soil Material ◽  
Lithostratigraphic Units ◽  
Borehole Logs

Although the main stratigraphic frame of the Neogene in North Belgium is well established still several issues remain. This is in particular the case at the boundaries of lithostratigraphic units and where lateral facies have developed. Not only are more biostratigraphic data needed but also the commonly used geophysical well logging needs a better information on the precise influence of the variable mineralogy in the sediments. In particular glauconite, muscovite and clay mineralogy need a detailed analysis. Such an analysis is carried out on the Antwerp Member of the Berchem Formation, the Diest Formation, the Kasterlee Formation and the Mol Formation with particular emphasis on the boundary intervals between these units. Clay minerals, glauconite, feldspars and muscovite are analyzed. Interstratified glauconite/smectite appears to be common in the low abundant dispersed clay fraction of sand rich in glauconite pellets. Marine units generally consist of detrital smectite-rich assemblages while kaolinite becomes more abundant in units under more continental influence. The presence of Fe-rich vermiculite in a clayey top facies of the Diest Formation indicates the influx of soil material containing weathered glauconite. It is common to find that the basal sediments of a new unit contain the mineralogical heritage of the underlying unit. The clay mineral content has helped to differentiate between units, to locate the boundaries between units and to understand the reworking that occurred at the base of new stratigraphic units. The mineralogical information can also be used to interpret the natural radioactivity and resistivity signals in the borehole logs.

A study of clay mineralogy and particle size

1957 ◽  
Vol 8 (1) ◽  
pp. 45 ◽  
Author(s):  
JS Hosking ◽  
ME Neilson ◽  
AR Carthew
Keyword(s):  
Particle Size ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Mineral Content ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Coarse Sand ◽  
Reverse Effect ◽  
Chemical Alteration ◽  
Intermediate Particle

A study of the mineralogy of the clay, silt, and sand fractions of 24 soils has shown that the clay minerals are distributed through all fractions of the soils. In granitic and other soils which are characterized by kaolinite, with mica, illite, or montmorillonoids sometimes present though subsidiary, the clay mineral content of the silts may be as high as in the clay fraction though on the average it is about 50 per cent.; in the sands, however, clay minerals are negligible. In basaltic or basic soils which are characterized by halloysite or nontronite or both, with other types subsidiary, the clay mineral content of the silts is somewhat less than that in granitic soils, but persists a t an average of 20 per cent, in the sands. The higher concentration of kaolinite in the silt fractions reflects the larger particle size of this mineral. The concentration of halloysite or nontronite in the sand fractions, and even the concentrations reached in the silts of soils containing these minerals, reflect their fibrous nature which allows the formation of stable interlaced aggregates. Overall the two types of mineral, altered (authigenic) and residual (allogenic), vary continuously with particle size; the former, constituting the bulk of the colloids, decrease to small amounts in the coarse sand, while the latter necessarily show the reverse effect. The silts contain both types of mineral in about equal amounts and thus represent the intermediate particle size of mechanical breakdown and chemical alteration.

Dating Bulk Sediments from Limnic Deposits Using a Grain-Size Approach

Radiocarbon ◽  
2013 ◽  
Vol 55 (2) ◽  
pp. 943-950 ◽  
Author(s):  
Leo Rothacker ◽  
Alexander Dreves ◽  
Frank Sirocko ◽  
Pieter M Grootes ◽  
Marie-Josée Nadeau
Keyword(s):  
Grain Size ◽  
Acid Treatment ◽  
Size Fraction ◽  
Sediment Layer ◽  
Bulk Sediment ◽  
Volcanic Origin ◽  
Size Fractions ◽  
Lake Sediment Core ◽  
Gravel Size ◽  
Grain Size Fractions

Radiocarbon measurements on bulk subaqueous sediments typically provide ages significantly older than actual time of deposition. This is generally caused by the presence of reworked organic compounds, which are depleted in 14C. To explore this issue of age heterogeneity, we collected 4 organic-rich samples from varying depths in a lake sediment core at the Gemündener Maar (Eifel, Germany), a lake of volcanic origin. We divided each sample into 5 standard grain-size fractions: gravel, sand, silt, clay, and 1 fraction smaller than 0.45 μm. These were cleaned separately using a standard acid-alkali-acid treatment. The highly organic gravel-size fraction provided the youngest 14C ages of all grain-size fractions and seems to be associated most closely with the time of deposition. By contrast, the silt and clay fractions show significantly older ages. If the investigated limnic sediment layer does not contain any identifiable terrestrial macrofossils, extracting and measuring coarser grain-size fractions instead of measuring bulk sediment samples will provide a better approximation of the time of sedimentation.

Ti distribution in grain-size fractions of Apollo soils 10084 and 71501

Icarus ◽  
2013 ◽  
Vol 226 (1) ◽  
pp. 891-897 ◽  
Author(s):  
W.G. Kong ◽  
B.L. Jolliff ◽  
Alian Wang
Keyword(s):  
Grain Size ◽  
Size Fractions ◽  
Grain Size Fractions

scholarly journals Geochemistry and mineralogy of recent sediments of Guanabara Bay (NE sector) and its major rivers - Rio de Janeiro State - Brazil

2001 ◽  
Vol 73 (1) ◽  
pp. 121-133 ◽  
Author(s):  
MARCIA DE MELO FARIA ◽  
BRAZ A. SANCHEZ
Keyword(s):  
Heavy Metal ◽  
Grain Size ◽  
Clay Minerals ◽  
Bottom Sediments ◽  
River Sediments ◽  
Size Fraction ◽  
River Mouth ◽  
Guanabara Bay ◽  
Metal Contents ◽  
Recent Sediments

Geochemical and clay mineralogical studies of bottom sediments collected along the Macacu and Caceribu rivers and Guanabara Bay were carried out in order to investigate the relationship between major source areas and recent sediments of the bay. Clay mineralogy includes different groups with selective distribution conditioned by geomorphic features and depositional settings. Micaceous clay minerals are abundant near parent rock in the upper course, whereas kaolinite derived from varied sources is gradually concentrated towards the estuary. In the Guanabara Bay, kaolinite accumulates near river mouths, while micaceous clay minerals are converted into mixed layers in the estuary. Analyses of heavy metal contents reveal higher levels of Zn and Cu in sediments of the bay than in river sediments. Profiles along rivers indicate a downstream decrease of heavy metals, whereas in the bay geochemical trends display greater variations. In general river mouth sediments present the lowest concentrations. At the north and east of Paquetá Island anomalous areas with the highest heavy metal contents occur. Cu tends to concentrate in < 2mum grain-size fraction and indicates an association with micaceous clay minerals in the upper river course. However, Cu retention seems to be further controlled by other components of bottom sediments due to changes in physical and chemical conditions of the estuarine environment. Zn shows unstable behavior along the rivers and concentrates in the bay. Pb displays small variations from river to bay sediments, and accumulates mainly in the < 63mum grain-size fraction without any association with clay mineral. Geoaccumulation indexes of Cu, Pb and Zn classify the study area as unpolluted in both studied rivers and in the NE sector of the bay, though the enrichment factors are higher in the bay. The study does not indicate those rivers as major sources of heavy metal pollution to the bay.

scholarly journals SEDIMENTÁRNĚ-GEOLOGICKÉ STUDIUM VYBRANÝCH KVARTÉRNÍCH SEDIMENTŮ V OKOLÍ BRNĚNSKÉ PŘEHRADY

2012 ◽  
Vol 19 (1-2) ◽  
Author(s):  
Marek Mikulík ◽  
Slavomír Nehyba ◽  
František Hubatka
Keyword(s):  
Grain Size ◽  
Left Bank ◽  
Quaternary Deposits ◽  
Size Fractions ◽  
Fluvial Deposits ◽  
Arid Conditions ◽  
Loess Deposits ◽  
Surrounding Landscape ◽  
Grain Size Fractions

Outcrops of Quaternary deposits are lining banks of the Brno dam. One of them is situated on the left bank ~ 250 m NW of the Osada pier. The sedimentary profile of Pleistocene deposits is composed of fluvial deposits of the Paleo – Svratka River covered by colluvial and eolian (loess) deposits. Alternation of various facies and various grain-size fractions reveals alternation of more or less arid conditions and also evolution of the surrounding landscape.

scholarly journals Grain size distribution, clay mineralogy and chemistry of bottom sediments from the outer Thermaikos Gulf, Aegean Sea, Greece

2004 ◽  
Vol 5 (1) ◽  
pp. 43
Author(s):  
K.G. PEHLIVANOGLOU ◽  
G. TRONTSIOS ◽  
A. TSIRAMBIDES
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Clay Minerals ◽  
Grain Size Distribution ◽  
Bottom Sediments ◽  
Clay Mineralogy ◽  
Aegean Sea ◽  
Wide Range ◽  
Differential Settling ◽  
Interstratified Phase

The Thermaikos Gulf constitutes the NW part of the North Aegean Sea and is limited eastward from the Chalkidiki Peninsula and westward from the Pieria Prefecture. Its plateau covers an area of 3,500 km2. The mechanisms responsible for the grain size distribution into the Gulf, the clay mineralogy and the chemistry of some bottom sediments from the outer Thermaikos Gulf, are examined. Source mixing during transportation, flocculation, differential settling processes and organic matter appear to be the main mechanisms for the distribution of clay minerals in shallow waters. All grain size fractions studied present a wide range of values confirming the extreme variations of the discharged load and the variability in marine processes. Plagioclases predominate over K-feldspars, while quartz is the most abundant mineral present. In addition, micas, chlorites, amphiboles and pyroxenes exist as primary and/or accessory minerals in all samples. Among clay minerals, illite predominates over smectite and smectite over chlorite (+ kaolinite). The ordered interstratified phase of I/S, with 30-35% S layers, is present in the 2-0.25µm fraction. The randomly interstratified phase of I/S, with 50% S layers, is present in the <0.25& micro; m fraction. On average the clay mineral content of the studied samples is: 48% I, 23% S, 17% Ch (+K) and 12% others for the 2-0.25µm fraction and 50% I, 30% S and 20% Ch (+K) for the <0.25 µm fraction. All these minerals are the weathering products of the rocks from the drainage basins of the rivers flowing into the Gulf, as well as of the Neogene and Quaternary unconsolidated sediments of the surrounding coasts. The terrigenous input, the water mass circulation and, to a lesser extent, the quality of the discharged material and the differential settling of grains, control the grain size distribution within the outer Thermaikos Gulf. The chemical composition of the analysed samples is generally in agreement with their mineral composition and signifies their terrigenous origin presenting discretely clastic character.

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