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.

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.

Clay mineral-grain size-calcite cement relationships in the Upper Cretaceous Chalk, UK: a preliminary investigation

Clay Minerals ◽  
2014 ◽  
Vol 49 (2) ◽  
pp. 299-325 ◽  
Author(s):  
C. V. Jeans ◽  
N. J . Tosca ◽  
X. F. Hu ◽  
S. Boreham
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Trace Element ◽  
Size Distribution ◽  
Clay Mineral ◽  
Preliminary Investigation ◽  
Clay Mineralogy ◽  
Minor Amount ◽  
Dioctahedral Smectite ◽  
Calcite Cement

AbstractThe idea is tested that the evolution of the Chalk’s clay mineral assemblage during diagenesis can be deduced by examining the relationships between its clay mineralogy, particle size distribution pattern, and the timing and trace element chemistry of the calcite cement. The preliminary results from five different examples of cementation developed at different stages of diagenesis in chalks with smectite-dominated clay assemblages suggest that this is a promising line of investigation. Soft chalks with minor amount of anoxic series calcite cement poor in Mg, Fe and Mn are associated with neoformed trioctahedral smectite and/or dioctahedral nontronite and talc. Hard ground chalk with extensive anoxic series calcite cement enriched in Mg and relatively high Fe, Mn and Sr are associated with neoformed glauconite sensu lato, berthierine and dioctahedral smectite, possibly enriched in Fe. The chalk associated with large ammonites shows extensive suboxic series calcite cement enriched in Mg, Mn and Fe that show no obvious correlation with its clay mineralogy. Nodular chalks with patchy suboxic series calcite cement enriched in Fe are associated with neoformed dioctahedral smectite, possibly enriched in Al, and berthierine. Regionally hardened chalk with extensive suboxic calcite cement and relatively high trace element contents contain pressure dissolution seams enriched in kaolin and berthierine. Laser-based particle-size distribution patterns suggest that each type of lithification has a typical complex clay mineral population, indicating that subtleties in mineralogy are not being identified and that there could be some control on the size and shape of the clay crystals by the different types of cementation.

Mineralogical and chemical heterogeneity of three standard clay mineral samples

Clay Minerals ◽  
1996 ◽  
Vol 31 (3) ◽  
pp. 417-422 ◽  
Author(s):  
H. M. Köster
Keyword(s):  
Particle Size ◽  
Chemical Analysis ◽  
Clay Mineral ◽  
Chemical Heterogeneity ◽  
X Ray Diffraction ◽  
Accessory Minerals ◽  
Size Fractions ◽  
X Ray ◽  
Compositional Variations

AbstractMineralogical and chemical heterogeneity within three standard clay mineral samples have been identified by X-ray diffraction and chemical analysis of various size-fractions. This heterogeneity is partly attributed to accessory minerals, but mostly to structural and compositional variations in the 2:1 layer minerals of different particle size in the same specimen.

Grain size control of sediment composition variability still not resolved

2020 ◽  
Author(s):  
Tomas Matys Grygar ◽  
Karel Hron ◽  
Ondrej Babek ◽  
Kamila Facevicova ◽  
Reneta Talska ◽  
...  
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Compositional Data ◽  
Size Control ◽  
Chemical Extraction ◽  
Sediment Composition ◽  
Geochemical Composition ◽  
Size Fractions ◽  
Grain Size Control ◽  
Log Ratio

<p>The compositional data analysis (CoDA), unbiased interpretation of geochemical composition of sediments and soils, must correctly treat several major challenges, well-known to environmental geochemists but still improperly handled. Among them, dilution by autochthonous components, e.g., biogenic carbonates or organic matter, and grain size effects are the most relevant. These effects cannot be eliminated by sample pre-treatment, e.g. by sieving or chemical extraction of diluting components, but they can be handled by implementation of interelement relationships and particle size distribution functions. The challenges of CoDA are principally twofold: geochemical/mineralogical and mathematical/statistical. Geochemical/mineralogical challenge is that complete deciphering of sediment composition would need knowledge of mineral composition (and stoichiometry of individual minerals and their content of major and trace elements) in each grain size fraction. This information can be achieved by analysis of finely divided grain-size fractions of studied sediments, which is enormously demanding, in particular in the silt and clay size fractions; that approach can, however, be found in scientific papers. Mathematical/statistical challenge consists in need to respect nature of compositional data (relative nature, i.e. scale dependence, data closure – content of each component impacts all other components), polymodal data distributions, including the cases when “outliers” (in terms of Gaussian distribution) are a regular part of compositional datasets. Compositional data are best treated using log-ratio methodology and robust algorithms (not based on the least squares fitting methods), which are not familiar to geoscientists.</p><p>Most traditional geochemical approaches to CoDA are based on empirical knowledge, models, and assumptions which are hardly proven, e.g. a tracer conservativeness or its grain size invariance, which are not easy tested independently. Most novel mathematical/statistical tools are too abstract and computations too complicate for common geochemists. The bottleneck here is to convert geochemical tasks to formal mathematical/statistical terms and develop novel tools, having chance to become routinely used in future.</p><p>We studied composition of 483 sediment samples from floodplain and reservoir impacted by historical pollution from chemical industry in Martktredwitz, Germany. We will demonstrate mathematically/statistically correct routes to (1) distinguishing anthropogenic portion of risk elements in sediments of variable grain size and (2) characterisation of grain size control of sediment composition. Task (1) is best achieved by robust regression with log-ratios of concentrations, which still needs certain a priori geochemical expertise. Task ad (2) is best achieved by the use of a functional analysis of particle size distributions (densities) based on Bayes spaces. To support our recommendations, insufficiency of PCA to solve task (1) will be demonstrated.</p>

Clay mineralogy of the Permo-Triassic strata of the British Isles: onshore and offshore

Clay Minerals ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 309-354 ◽  
Author(s):  
C. V. Jeans
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
North Sea ◽  
Mixed Layer ◽  
Early Stage ◽  
Regional Distribution ◽  
Clay Mineralogy ◽  
British Isles ◽  
Mineral Assemblages ◽  
Red Bed

AbstractThe regional distribution, mineralogy, petrology and chemistry of the detrital and authigenic clay minerals associated with the Permo-Triassic strata (excluding the Rotliegend: see Ziegler, 2006; this volume), of the onshore and offshore regions of the British Isles are reviewed within their stratigraphical framework. The origin of these clay minerals is discussed in relation to current hypotheses on the developments of the Mg-rich clay mineral assemblages associated with the evaporitic red-bed Germanic facies of Europe and North Africa.Composite clay mineral successions are described for seven regions of the British Isles — the Western Approaches Trough; SW England; South Midlands; Central Midlands; the Cheshire Basin; NE Yorkshire; and the Central North Sea. The detrital clay mineral assemblages of the Early Permian strata are variable, consisting of mica, smectite, smectite-mica, kaolin and chlorite, whereas those of the Late Permian and the Trias are dominated by mica, usually in association with minor Fe-rich chlorite. The detrital mica consists of a mixture of penecontemporaneous ferric mica, probably of pedogenic origin, and recycled Pre-Permian mica. In the youngest Triassic strata (Rhaetian), the detrital clay assemblages may contain appreciable amounts of poorly defined collapsible minerals (irregular mixed-layer smectite-mica-vermiculite) and kaolin, giving them a Jurassic aspect. There are two types of authigenic clay mineral assemblages. Kaolin may occur as a late-stage diagenetic mineral where the original Permo-Triassic porewaters of the sediment have been replaced by meteoritic waters. A suite of early-stage diagenetic clay minerals, many of them Mg-rich, are linked to the evaporitic red-bed facies — these include sepiolite, palygorskite, smectite, irregular mixed- layer smectite-mica and smectite-chlorite, corrensite, chlorite and glauconite (sensu lato). The sandstones and mudstones of the onshore regions of the British Isles display little or no difference in their detrital and authigenic clay mineral assemblages. In contrast, the sandstones of the offshore regions (North Sea) show major differences with the presence of extensive chloritic cements containing Mg-rich and Al-rich chlorite, irregular mixed-layer serpentine-chlorite, and mica.

scholarly journals Growth Mechanism of Siliceous Cement in Tight Sandstone and Its Influence on Reservoir Physical Properties

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3133 ◽  
Author(s):  
Bo Jiu ◽  
Wenhui Huang ◽  
Jing Shi ◽  
Mingqian He
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Clay Mineral ◽  
Growth Mechanism ◽  
Forming Process ◽  
Tight Sandstone ◽  
High Quality ◽  
Factors Affecting ◽  
Reservoir Permeability ◽  
Thin Section Analysis

To investigate the effect of siliceous cementation on the densification of sandstone and the forming process of tight sandstone, based on cathodoluminescence, scanning electron microscopy and thin section analysis, the growth mechanism and characteristics of quartz particles in tight sandstone formations are explored. Meanwhile, combined with conventional core analysis and X-ray diffraction experiments, the factors affecting the crystallization of quartz particles, including the chlorite content, grain size and clay mineral, are analyzed, respectively. The entire siliceous cementation is divided into two processes. The first part is the process in which the weathered and rounded particles in the formation are restored to the hexagonal dipyramid crystal by siliceous cementation. The second part is the process of coaxial growth that the hexagonal dipyramid crystal continues to increase with the form of micro-quartz film. As siliceous cements continue to increase, the petrological characteristics of sandstones are constantly changing. The tight sandstone developed in the study area is composed of lithic sandstone and quartz lithic sandstone. Based on the analysis results, 2D and 3D evolution models are established for densification of two different lithic sandstones. When the content of siliceous cement in the study area is less than 17%, the porosity of tight sandstone increases with the increase of cement. When the content of cement is more than 17%, the porosity of tight sandstone is negatively correlated with the content of cement. When the cement content is greater than 10%, the reservoir permeability is negatively correlated with it. Furthermore, the particle size mainly affects the permeability of reservoir, and the particle size is negatively correlated with the permeability of tight sandstone. The most high-quality tight sandstone reservoir in the study area is in the first cementation stage when siliceous cements are distributed in porphyritic texture with the content of 10–15% and a grain size of 0.2–0.3 mm. In addition, the relatively high-quality reservoir is the one developing clay mineral film with a content of cementation about 5–12%.

Clay mineralogy of the Jurassic strata of the British Isles

Clay Minerals ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 187-307 ◽  
Author(s):  
C. V. Jeans
Keyword(s):  
Clay Mineral ◽  
North Sea ◽  
Mixed Layer ◽  
Clay Mineralogy ◽  
List Type ◽  
British Isles ◽  
Southern England ◽  
The North ◽  
Wide Range ◽  
Mineral Assemblages

AbstractThe nature and origin of the clay mineralogy of the Jurassic strata of the British Isles are described and discussed within their lithological and biostratigraphical framework using published and unpublished sources as well as 1800 new clay mineral analyses. Regional clay mineral variation is described systematically for the following formations or groups:England and Wales(i)Hettangian-Toarcian strata (Lias Group): Redcar Mudstone Fm.; Staithes Sandstone Fm.; Cleveland Ironstone Fm.; Whitby Mudstone Fm.; Scunthorpe Mudstone Fm.; Blue Lias Fm.; Charmouth Mudstone Fm.; Marlstone Rock Fm.; Dyrham Fm.; Beacon Limestone Fm.; Bridport Sand Fm.(ii)Aalenian-Bajocian (Inferior Oolite Group): Dogger Fm.; Saltwick Fm.; Eller Beck Fm.; Cloughton Fm.; Scarborough Fm.; Scalby Fm. (in part); Northampton Sand Fm.; Grantham Fm.; Lincolnshire Limestone Fm.; Rutland Fm. (in part); Inferior Oolite of southern England.(iii)Bathonian (Great Oolite Group): Scalby Fm. (in part); Rutland Fm. (in part); Blisworth Limestone Fm.; Great Oolite Group of southern England; Forest Marble Fm.; Cornbrash Fm. (in part).(iv)Callovian-Oxfordian: Cornbrash Fm. (in part); Kellaways Fm.; Oxford Clay Fm.; Corallian Beds and West Walton Beds; Ampthill Clay Fm.(v)Kimmeridgian-Tithonian: Kimmeridge Clay Fm.; Portland Sandstone Fm.; Portland Limestone Fm.; Lulworth Fm.; Spilsby Sandstone Fm. (in part). Scotland(vi)Hettangian-Toarcian: Broadfoot Beds, Dunrobin Bay Fm. Aalenian-Portlandian: Great Estuarine Group (Dunkulm, Kilmaluag and Studiburgh Fm.s); Staffin Shale Fm.; Brora Coal Fm.; Brora Argillaceous Fm.; Balintore Fm.; Helmsdale Boulder Beds (Kimmeridge Clay Fm.).Dominating the Jurassic successions are the great marine mudstone formations — the Lias Group, Oxford Clay, Ampthill Clay and Kimmeridge Clay. These are typically characterized by a detrital clay mineral assemblage of mica, kaolin and poorly defined mixed-layer smectite-mica-vermiculite minerals with traces of chlorite. Detailed evidence suggests that this assemblage is derived ultimately from weathered Palaeozoic sediments and metasediments either directly or by being recycled from earlier Mesozoic sediments. A potassium-bearing clay is a persistent component and formed at approximately the same time as the deposition of the host sediment, either in coeval soils or during very early diagenesis.At three periods during the deposition of the Jurassic (Bajocian-Bathonian, Oxfordian and late Kimmeridgian-Tithonian), the detrital clay assemblage was completely or partially replaced by authigenic clay mineral assemblages rich in kaolin, berthierine, glauconite or smectite minerals. Associated with these changes are major changes in the lithofacies, with the incoming of non-marine and proximal marine strata. The authigenic clay assemblages rich in kaolin and berthierine are generally restricted to the non-marine and very proximal marine beds, those rich in glauconite or smectite are typical of the marine lithofacies. Clay mineral assemblages containing vermiculite and mixed-layer vermiculite-chlorite sometimes occur in the non-marine and proximal marine facies. The causes of these major changes in lithofacies and clay mineralogy are discussed, and present evidence favours an important volcanogenic influence and not climatic control. It is suggested that the Bajocian-Bathonian, Oxfordian and Late Kimmeridgian-Tithonian were periods of enhanced volcanic activity, with centres probably located in the North Sea and linked to regional tectonic changes which caused major modifications of the palaeogeography of the British Isles. The most important of these changes was the development of the central North Sea Rift Dome during the Bajocian and Bathonian. Volcanic ash was widespread in both the non-marine and marine environments and its argillization under different conditions provided the wide range of authigenic clay mineral assemblages.Metre-scale clay mineral cyclicity is widespread in most of the Jurassic mudstone formations that have been examined in sufficient detail. The cyclicity is defined by systematic variations in the mica/ collapsible minerals (mixed-layer smectite-mica-vermiculite) ratio. This variation is unrelated to changes in lithology and its possible origins are discussed in detail using data from the Kimmeridge Clay provided by Reading University's contribution to the Rapid Global Geological Events (RGGE) Project.

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.

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