THE OCCURRENCE OF CHLORITE AND VERMICULITE IN THE CLAY FRACTION OF THREE BRITISH COLUMBIA SOILS

1959 ◽  
Vol 39 (2) ◽  
pp. 246-253
Author(s):  
A. A. Theisen ◽  
G. R. Webster ◽  
M. E. Harward
Keyword(s):  
British Columbia ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Vancouver Island ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Past ◽  
Surface Samples

The clay mineralogy of surface samples from three soils on Vancouver Island which had been used in fertility experiments was determined by X-ray diffraction. Chlorite was identified as the predominant mineral in all three soils. Vermiculite was present in discrete units in the Chemainus soil and interstratified with chlorite in the Fairbridge and Merville soils. Kaolinite may also have been a constituent; this could not be determined since the use of certain criteria, proposed in the past for the identification of kaolinite in the presence of chlorite, proved unsuccessful. It was concluded that no universal criterion, which holds true in all cases, exists for distinguishing kaolinite in the presence of chlorite.

scholarly journals Provenance and Sedimentary Context of Clay Mineralogy in an Evolving Forearc Basin, Upper Cretaceous-Paleogene and Eocene Mudstones, San Joaquin Valley, California

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Andrew Hurst ◽  
Michael Wilson ◽  
Antonio Grippa ◽  
Lyudmyla Wilson ◽  
Giuseppe Palladino ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Upper Cretaceous ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Bulk Rock ◽  
X Ray Diffraction ◽  
Arc Volcanism ◽  
X Ray ◽  
Magmatic Arc ◽  
Tropical Weathering

Mudstone samples from the Moreno (Upper Cretaceous-Paleocene) and Kreyenhagen (Eocene) formations are analysed using X-ray diffraction (XRD) and X-ray fluorescence (XRF) to determine their mineralogy. Smectite (Reichweite R0) is the predominant phyllosilicate present, 48% to 71.7% bulk rock mineralogy (excluding carbonate cemented and highly bio siliceous samples) and 70% to 98% of the <2 μm clay fraction. Opal CT and less so cristobalite concentrations cause the main deviations from smectite dominance. Opal A is common only in the Upper Kreyenhagen. In the <2 μm fraction, the Moreno Fm is significantly more smectite-rich than the Kreyenhagen Fm. Smectite in the Moreno Fm was derived from the alteration of volcaniclastic debris from contemporaneous rhyolitic-dacitic magmatic arc volcanism. No tuff is preserved. Smectite in the Kreyenhagen Fm was derived from intense sub-tropical weathering of granitoid-dioritic terrane during the hypothermal period in the early to mid-Eocene; the derivation from local volcanism is unlikely. All samples had chemical indices of alteration (CIA) indicative of intense weathering of source terrane. Ferriferous enrichment and the occurrence of locally common kaolinite are contributory evidence for the intensity of weathering. Low concentration (max. 7.5%) of clinoptilolite in the Lower Kreyenhagen is possibly indicative of more open marine conditions than in the Upper Kreyenhagen. There is no evidence of volumetrically significant silicate diagenesis. The main diagenetic mineralisation is restricted to low-temperature silica phase transitions.

THE CLAY MINERALS IN SOME BRITISH COLUMBIA SUBSOILS

1962 ◽  
Vol 42 (2) ◽  
pp. 296-301 ◽  
Author(s):  
J. S. Clark ◽  
J. E. Brydon ◽  
H. J. Hortie
Keyword(s):  
British Columbia ◽  
Diffraction Analysis ◽  
Clay Minerals ◽  
Clay Mineralogy ◽  
X Ray Diffraction ◽  
The South ◽  
Parent Materials ◽  
X Ray ◽  
Northeastern Part ◽  
Montmorillonitic Clay

X-ray diffraction analysis was used to identify the clay minerals present in fourteen subsoil samples that were selected to represent some more important clay-bearing deposits in British Columbia. The clay mineralogy of the subsoils varied considerably but montmorillonitic clay minerals tended to predominate in the water-laid deposits of the south and illite in the soil parent materials of the Interior Plains region of the northeastern part of the Province.

THE OCCURRENCE OF GIBBSITE IN A BRITISH COLUMBIA SOIL

1978 ◽  
Vol 58 (4) ◽  
pp. 529-533
Author(s):  
N. M. MILES ◽  
G. C. SCOTT ◽  
A. J. GREEN
Keyword(s):  
British Columbia ◽  
Vancouver Island ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Identity ◽  
Ir Bands

Gibbsite occurs in all horizons of an Orthic Dystric Brunisol near Port Alberni, Vancouver Island. The structural identity of gibbsite was established by (i) X-ray diffraction maxima at 4.85, 4.38 and 2.38 Å, which disappeared at 260 °C, (ii) principal IR bands at 3,615, 3,520, 3,428 and 3,380 cm−1 and (iii) a DTA endotherm near 300 °C.

Some aspects of the genesis of an alpine humus soil

Soil Research ◽  
1973 ◽  
Vol 11 (1) ◽  
pp. 1 ◽  
Author(s):  
R Brewer ◽  
AD Haldane
Keyword(s):  
Sudden Change ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Soil Formation ◽  
Mineral Weathering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Humus Soil ◽  
In Situ Weathering

An alpine humus soil profile has been examined in the field, in thin section and by X-ray diffraction. The presence of a stone line and the sudden change in characteristics across the stone line, including particle size distribution, degree of exfoliation of the micas, major mineral composition, and clay mineralogy suggest that this is a polygenetic profile consisting of two soil stratigraphic units. There has been little pedological reorganization within either unit, soil formation consisting essentially of in situ weathering, removal of soluble constituents, and accumulation of organic matter, with some biological activity, in the upper unit. It is shown that gibbsite derived from weathering of feldspar is a major component of the clay fraction, especially in the lower unit. The clay mineralogy is considered in relation to proposed mineral weathering sequences and weathering in a yellow podzolic soil.

Clay minerals in the agricultural surface soils in the Central United States

Clay Minerals ◽  
2001 ◽  
Vol 36 (3) ◽  
pp. 277-294 ◽  
Author(s):  
B. Velde
Keyword(s):  
United States ◽  
Clay Minerals ◽  
Agricultural Soils ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Parent Material ◽  
X Ray Diffraction ◽  
Charge Site ◽  
X Ray ◽  
Central United States

AbstractA survey of the clay fraction at the surface of 86 loam and silt loam agricultural soils from the Central United States was undertaken to observe the possible influences of climate and parent material (dominantly phyllosilicates in this study) on the clay mineralogy of the upper portions of the soils, for the most part in Mollisol–Alfisol order soils.Decomposed X-ray diffraction spectra show that the most abundant clay minerals are two disordered illite-smectite (I-S) minerals, one with ∼50% smectite layers and another, less abundant, disordered I-S phase with 20% smectite. These minerals usually co-exist in the same samples. The charge site in both of these I-S minerals is both beidellitic and montmorillonitic in the expanding layers. A relatively large proportion of these smectite layers (up to 20%) are of high charge.There seems to be a convergence in mineralogy towards mixed-layer phases formed under a range of mid-Continent climates from a range of phyllosilicate parent materials.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

RNA polymerase: Preparation and structural analysis of helical polymers

1984 ◽  
Vol 42 ◽  
pp. 152-153
Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi
Keyword(s):  
Structural Analysis ◽  
Rna Polymerase ◽  
Molecular Level ◽  
X Ray Diffraction ◽  
Helical Polymers ◽  
X Ray ◽  
E Coli ◽  
The Past ◽  
Ordered Arrays ◽  
Low Ionic Strength

While DNA-dependent RNA polymerase represents one of the key enzymes involved in transcription and ultimately in gene expression in procaryotic and eucaryotic cells, little progress has been made towards elucidation of its 3-D structure at the molecular level over the past few years. This is mainly because to date no 3-D crystals suitable for X-ray diffraction analysis have been obtained with this rather large (MW ~500 kd) multi-subunit (α2ββ'ζ). As an alternative, we have been trying to form ordered arrays of RNA polymerase from E. coli suitable for structural analysis in the electron microscope combined with image processing. Here we report about helical polymers induced from holoenzyme (α2ββ'ζ) at low ionic strength with 5-7 mM MnCl2 (see Fig. 1a). The presence of the ζ-subunit (MW 86 kd) is required to form these polymers, since the core enzyme (α2ββ') does fail to assemble into such structures under these conditions.

Strain Measurement by X-ray Diffraction Methods

1949 ◽  
Vol 1 (3) ◽  
pp. 211-224
Author(s):  
G. B. Greenough
Keyword(s):  
Strain Measurement ◽  
Plastic Anisotropy ◽  
Stress And Strain ◽  
Routine Method ◽  
X Ray Diffraction ◽  
Strain Measurements ◽  
X Ray ◽  
The Past ◽  
Polycrystalline Metals ◽  
The Individual

SummaryMany papers have been written on the measurement of strain by X-ray diffraction methods and on the interpretation of these strains in terms of stresses. Whereas, during the past few years, the experimental methods of determining the strains have. remained largely unchanged, research has shown that the older techniques for calculating stresses from strains are not always valid.In this paper an attempt is made to describe some of the principles of strain measurement by X-ray diffraction methods to those who are unfamiliar with the methods. The types of stress and strain systems which may exist in polycrystalline metals are then considered, particular attention being paid to the effect of the elastic and plastic anisotropy of the individual crystals. Some indication is given as to how the earlier methods of interpreting X-ray strain measurements should be modified, but no rigid routine method is proposed for use in a general case.

scholarly journals The Occurrence of Authigenic Clay Minerals in Alkaline-Saline Lakes, Pantanal Wetland (Nhecolândia Region, Brazil)

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 718
Author(s):  
Isis Armstrong Dias ◽  
Leonardo Fadel Cury ◽  
Bruno Guimarães Titon ◽  
Gustavo Barbosa Athayde ◽  
Guilherme Fedalto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Clay Minerals ◽  
Saline Lakes ◽  
Clay Fraction ◽  
Water Bodies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Fine Clay ◽  
Pantanal Wetland

Mg clay minerals are usually associated with carbonates in alkaline-saline environments, precipitated from solution and/or transformation from other minerals. The aim of this research is to identify the mineralogy and geochemistry of clay minerals in different alkaline lakes in the Nhecolândia region, the southernmost region of the Pantanal wetland (Brazil). Sediment samples were analyzed by X-ray diffraction, X-ray fluorescence, scanning electron microscopy and transmission electron microscopy. Water samples were analyzed, determining their main cations and anions, in order to understand their relationship with the clays. The analyses allowed classifying the water bodies as saline, oligosaline and freshwater lakes. The sediments are composed mainly of quartz and a fine-clay fraction, dominated by illite, kaolinite and smectite. The XRD results showed illite and smectite mixed-layered in the saline lakes at Barranco Alto farm, whereas at Nhumirim farm, trioctahedral smectite was only observed in one lake. The smectite minerals were normally identified coupled with calcite at the top of the sequences, associated with exopolymeric substances (EPS) in the lakes, suggesting that these minerals are precipitating due to the physical-chemical and biological conditions of the water bodies.

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