scholarly journals Clay mineral investigation of the Rhaetic - Jurassic - Lower Cretaceous sediments of the B0rglum 1 and Uglev 1 wells, Denmark

1985 ◽  
Vol 34 ◽  
pp. 97-110
Author(s):  
Birthe J. Schmidt
Keyword(s):  
Clay Mineral ◽  
Lower Cretaceous ◽  
Rapid Change ◽  
Early Diagenesis ◽  
Burial Diagenesis ◽  
X Ray Diffraction ◽  
Geochemical Environment ◽  
X Ray ◽  
Mineral Assemblages ◽  
Scanning Electron

The clay mineral assemblages of the Rhaetic -Jurassic - Lower Cretaceous sequences from the Borglum 1 and U glev 1 wells have been investigated to evaluate the diagenesis of the sediments. Besides grain size analyses, the methods include X-ray diffraction analyses and scanning electron microscopy in combination with energy dispersive analyses. The distribution of clay minerals essentially shows a rapid change from smectite to kaolinite dominance with increasing depth. Kaolinite dominates the older sediments below the lower part of the Haldager For­mation, including the Fjerritslev and Gassum Formations, while smectite dominates the younger sedi­ments above the upper part of the Haldager Formation, which includes Bream and Vedsted Formations. This change is primarily attributed to differences in the composition of the mineralogy and geochemical environment rather than to burial diagenesis. While some early diagenesis has taken place to form authi­genic kaolinite, thorough depth-dependent diagenesis can hardly be detected.

A hydrothermal clay mineral assemblage at the Late Proterozoic unconformity in the Buenos Aires Complex – La Tinta Formation, Barker area, Tandilia Ranges (Argentina)

Clay Minerals ◽  
2010 ◽  
Vol 45 (2) ◽  
pp. 209-224 ◽  
Author(s):  
J. C. Martínez ◽  
J. A. Dristas ◽  
H.-J. Massonne ◽  
T. Theye
Keyword(s):  
Clay Mineral ◽  
White Mica ◽  
X Ray Diffraction ◽  
Aluminium Phosphate ◽  
X Ray ◽  
Late Proterozoic ◽  
Eu Anomaly ◽  
Rapid Changes ◽  
Mineral Assemblages ◽  
First Time

AbstractA general alteration pattern of two transitional clay mineral assemblages was determined by petrography and X-ray diffractometry studies at the Tandilia Late Proterozoic unconformity zone, around the Barker locality: (1) K-white mica + chlorite + calcite ± anatase-rutile ± secondary quartz (farther from the unconformity) and (2) pyrophyllite + K-white mica + Ti-rich hematite ± aluminium phosphate-sulphate minerals ± tourmaline ± anatase-rutile (closer to the unconformity). The local occurrence of Na in K-white micas and K-Na in pyrophyllite is described for the first time. Possible interlayering with intermediate K-Na mica and paragonite is indicated by detailed X-ray diffraction analyses. A negative Eu anomaly (Eu/Eu* = 0.24), strongly positive Eu anomaly (Eu/Eu* =11.7) and positive Ce anomaly characterized rapid changes from an unaltered basement to the most altered basement and sedimentary rocks at the unconformity. Aluminium phosphate-sulphate minerals dominate patterns of LREE. A model of hydrothermal alteration comparable to that of unconformity-related uranium deposits is presented.

scholarly journals An Investigation on the Effect of Solvent and Heat to Clay Minerals in Shaly Sandstone

2020 ◽  
Vol 20 (6) ◽  
pp. 1230
Author(s):  
Wan Zairani Wan Bakar ◽  
Ismail Mohd Saaid ◽  
Mohd Riduan Ahmad ◽  
Husna Hayati Jarni ◽  
Siti Qurratu’ Aini Mahat
Keyword(s):  
Clay Mineral ◽  
Direct Contact ◽  
Molecular Level ◽  
X Ray Diffraction ◽  
X Ray ◽  
Effect Of Solvent ◽  
Direct Exposure ◽  
Shaly Sand ◽  
Shaly Sandstone ◽  
Scanning Electron

Core cleaning could be complicated for samples that contain a high amount of clays. Some clays are delicate and exposure to solvent and heat would damage or alter its properties. In this study, we investigated the effect of direct exposure of solvent and heat to clay mineral properties based on petrographical data from X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-Ray (EDX). Experiments were performed on sidewall core samples taken in a shaly sand zone. The FTIR data did not show any changes at the molecular level to the clay mineral after direct contact with the selected solvent. The FESEM images showed some illite floccules collapse in the samples exposed to oven-drying at 60 °C.

Authigenic palygorskite in Miocene sediments in Linxia basin, Gansu, northwestern China

Clay Minerals ◽  
2007 ◽  
Vol 42 (1) ◽  
pp. 45-58 ◽  
Author(s):  
H. L. Hong ◽  
N. Yu ◽  
P. Xiao ◽  
Y. H. Zhu ◽  
K. X. Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Clay Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Particles ◽  
Transmission Electron ◽  
Mineralogical Characteristics ◽  
Linxia Basin ◽  
Hydrolysis Of ◽  
Scanning Electron

AbstractThe mineralogical characteristics of authigenic palygorskite occurring with chlorite and illite in Miocene sediments in Linxia basin were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). The XRD results suggest that the mineral composition of the sediments includes mainly quartz, chlorite, illite, calcite, plagioclase, orthoclase, minor palygorskite and small amounts of gypsum and ankerite. Two kinds of palygorskite were observed in the sediments, relatively straight fibrous particles found in matted, felted masses associated with platy chlorite and silky aggregates found in the void spaces. The former probably replaces chlorite grains, growing from the edges or the fissures of chlorite particles. Chlorite grains exhibit bay-shaped or rounded edges, with ambiguous felted boundaries between chlorite particles, indicative of an intensive dissolution process and the growth of palygorskite at the expense of chlorite. Palygorskite is also observed as inclusions within calcite, sprouting from or coating calcite surfaces, suggesting that palygorskite crystallized from solution. The textural relations of palygorskite and the occurrence of ankerite and the characteristically Fe-bearing palygorskite in the sediments suggest the destruction and hydrolysis of chlorite. The ankerite seems to be preferentially present in the void spaces, closely associated with chlorite and illite; fibrous palygorskite crystallizes at the edges of these clay mineral particles and the platy clay mineral particles are gradually replaced by fibrous palygorskite crystals, suggesting that alteration of chlorite to palygorskite involves an interaction with water during the diagenetic process.

Occurrence of chloritic intergrades in the Recent sediments of the Arno River (Italy)

Clay Minerals ◽  
1979 ◽  
Vol 14 (1) ◽  
pp. 47-65 ◽  
Author(s):  
F. Sartori ◽  
R. Riffaldi ◽  
R. Levi-Minzi
Keyword(s):  
Diffraction Pattern ◽  
Clay Mineral ◽  
Depositional Environments ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Treatments ◽  
Mineral Assemblages ◽  
Recent Sediments

AbstractClay mineral assemblages from a Quaternary sequence, sampled near the estuary of the Arno River, commonly contain some intergrade minerals, associated with other 14 Å phases and with illite and subordinate amounts of a kaolin mineral. The X-ray diffraction characteristics of such intergrade phases and their thermal modifications (100–600°C) are analysed and described.The effectiveness of some chemical treatments for removal of interlayer material is investigated and the results discussed on the basis of X-ray diffraction pattern and C.E.C. changes. Finally the properties of these intergrades are compared with those of the 14 Å phases present in the sediments carried by the Arno River and its tributary the Era River as well as with those of a soil from the Era watershed. Hypotheses are expressed about the probable relationships between degree of chloritization and characteristics of the depositional environments.

scholarly journals Kaolinization processes in the phyolitic rocks of Kefalos, Kos island, Aegean Sea, Greece

2001 ◽  
Vol 34 (3) ◽  
pp. 867 ◽  
Author(s):  
D. PAPOULIS ◽  
P. TSOLIS - KATAGAS
Keyword(s):  
Electron Microscopy ◽  
Aegean Sea ◽  
Chemical Analyses ◽  
Bulk Rock ◽  
Secondary Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Assemblages ◽  
Analytical Scanning Electron Microscopy ◽  
Scanning Electron

Kaolin occurrences in the South Kefalos peninsula, Kos island, Aegean sea, Greece, are products of hydrothermal alteration of rocks of rhyolitic composition. The chemical, mineralogical and textural characteristics of kaolin occurrences were investigated by X-Ray diffraction (XRD), Analytical scanning electron microscopy (SEM) and bulk rock chemical analyses. Attempts have been made to correlate the primary with secondary mineral assemblages and to establish the factors controlling the stepwise character of the transition from the fresh rhyolitic to kaolinized rocks. The kaolinization processes follows two main alteration pathways: I) Kfeldspar —» Mixed-layer kaolinite-smectite —» kaolinite —> dickite. II) Na-plagioclase —> kaolinite —> dickite

scholarly journals Application of the capillary method in micro X-ray diffractometry (µ-XRD): A useful technique for the characterization of small amounts of clay minerals

2020 ◽  
Author(s):  
Ivett Kovács ◽  
Tibor Németh ◽  
Gabriella B. Kiss ◽  
Zsolt Benkó
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Rapid Preparation ◽  
Thin Sections ◽  
X Ray ◽  
Capillary Method ◽  
Mineral Assemblages ◽  
Ph Conditions

AbstractThe laboratory micro X-ray diffraction (μ-XRD) technique is a suitable method to study minerals in-situ in whole-rock specimens without any sample preparation or in polished thin sections, and even in small amounts in powdered form. The micro X-ray diffraction method uses the conventional, closed-tube X-ray generator, but modifications were needed in the diffraction column, sample holder and detector in order to achieve μ-XRD capability.In this paper, we present a case study of the capillary method used in µ-XRD on hydrothermal clay mineral assemblages that formed in the Velence Mts (Hungary). The capillary method in µ-XRD has many advantages in the investigation of small amounts of clay minerals: (1) easy and rapid preparation of randomly oriented, powdered samples; (2) rapid measurements; (3) accurate diffraction patterns. By using the capillary method, the formation of preferred orientation can be eliminated; thus the (hkl) reflection of the clay minerals can be precisely measured. Illite polytype quantification and the investigation of (060) reflection of clay minerals can be used satisfactorily in µ-XRD.Hydrothermal clay mineral assemblages are indicative of temperature and pH. Their examination can determine the physicochemical parameters of the hydrothermal fluids that interacted with the host granite in the Velence Mts. The analyzed hydrothermal clay minerals from the western part of the mountains suggest lower temperatures (150–200 °C) and intermediate pH conditions. In contrast, the clay mineral assemblages' characteristics for the eastern part of the mountains indicate more intense argillization and higher temperatures (∼220 °C) and intermediate pH conditions.

scholarly journals Investigation of the Orientation of Ions in the Interlayer of CTAB Pillared Montmorillonite

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Semra Karaca ◽  
Ahmet Gürses ◽  
Mehtap Ejder Korucu
Keyword(s):  
Clay Mineral ◽  
Interlayer Space ◽  
Contact Angles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pillared Montmorillonite ◽  
Zeta Potentials ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Scanning Electron

The orientation of CTA+in the interlayer of organic pillared montmorillonite prepared by adding different amounts of surfactant corresponding to the CEC of the pristine clay mineral has been studied using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectra. Morphology of the samples was examined by scanning electron microscopy (SEM). The results are supported by the measurements of zeta potentials and contact angles of pristine clay and organoclay samples. From the XRD results, a series of arrangement models of CTA+in the interlayer of montmorillonite have been proposed as lateral-bilayer, pseudotrilayer, paraffin-type-monolayer and pseudotrilayer, paraffin-type-bilayer and pseudotrilayer for 0.5, 1, 1.5, and 2.0 CEC, respectively. FTIR spectrum and contact angle measurements of pristine montmorillonite and organoclays indicated the incorporation of surfactant and the changing of hydrophility in the different OMts. This study demonstrates that not only the arrangement model of surfactant, but also the morphology of organoclay strongly depends on the surfactant packing density within the montmorillonite interlayer space. In addition, it can be also proposed that, the magnitude of surface charge or its distribution on clay mineral might be an important factor for expansion characteristics of organoclay.

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.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

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