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.

Two-step mode of clay formation in the extensional basins: Cambrian–Ordovician clastic rocks of the Antalya unit, SW Turkey

Clay Minerals ◽  
2017 ◽  
Vol 52 (3) ◽  
pp. 365-389 ◽  
Author(s):  
Ö. Bozkaya ◽  
H. Yalçin ◽  
P.A. Schroeder
Keyword(s):  
Spatial Relations ◽  
White Mica ◽  
Chemical Characteristics ◽  
Burial History ◽  
X Ray Diffraction ◽  
X Ray ◽  
Clastic Rocks ◽  
Sw Turkey ◽  
Mineral Assemblages ◽  
Clay Formation

AbstractOrdovician clastic rocks of the Antalya unit in SW Turkey bear mineralogical/geochemical evidence of Triassic extensional rift timing and spatial relations. The crystal chemistry of the phyllosilicate assemblages (illite, chlorite, kaolinite, mixed-layer illite-smectite, chlorite-vermiculite and chlorite-smectite) is consistent with the rock experiencing a multi-generational burial history. The appearance of kaolinite and illite-smectite-bearing rocks in the Antalya unit is characteristic of diagenetic-anchimetamorphic conditions and is of higher grade than their anchi-epizonal equivalents in other regions of the Tauride belt. Illites and chlorites are of both detrital and authigenic origin, whereas I-S and kaolinites are authigenic. Detrital micas have been altered to chlorite and K-white mica stacks in which relicts suggest the chlorites were derived from detrital biotites. The broad X-ray diffraction illite peaks show that they are composed both of illite and illite-smectite. Na,K-mica and paragonite occur within the chlorite-mica stacks as replacements of muscovite, probably driven by Na-rich solutions. The authigenic clays were formed within the microporous matrix and the interplanar spaces of {001} planes of chlorite-mica stacks, with textures independent of the bedding and foliation planes of the rocks. The authigenic chlorites exhibit higher Si and Fe and lower Mg contents than their detrital counterparts. Authigenic chlorite thermometry indicates rift-related temperatures of 50–150°C, whereas pre-rift detrital chlorites formed at temperatures of  >200°C. Authigenic illite and illite-smectite are phengitic in composition and contain more Si, Mg, Fe and Ca and less Al and K than detrital K-white micas. The textural, mineralogical and chemical characteristics support the hypothesis that the mineral assemblages were a result of a two-step mode of formation with diagenetic overprints of previously anchizonal rocks in extensional basin conditions.

Occurrence, composition and paragenesis of the zeolites and associated minerals in the alkaline basalt of a maar-type volcano at Haláp Hill, Balaton Highland, Hungary

2011 ◽  
Vol 75 (6) ◽  
pp. 2869-2885 ◽  
Author(s):  
P. Kónya ◽  
S. Szakáll
Keyword(s):  
Energy Dispersive Spectrometry ◽  
Hydrothermal Activity ◽  
Volcanic Field ◽  
Alkaline Basalt ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wavelength Dispersive Spectrometry ◽  
Mineral Assemblages ◽  
First Time ◽  
Mn Oxides

AbstractHaláp Hill is an eroded remnant of young (∼3 Ma) alkaline basalt in the western part of the Bakony–Balaton Highland Volcanic Field, Tapolca, Hungary. Cavities in the basalt contain miarolitic minerals (augite, apatite, magnetite, plagioclase and sanidine), zeolites (analcime, chabazite-Ca, chabazite-Na, garronite, gismondine, gmelinite-Ca, gmelinite-Na, gobbinsite, gonnardite-Na, natrolite, mesolite, phillipsite-Ca, phillipsite-K, phillipsite-Na and scolecite) and other secondary minerals (calcite, smectite-group minerals, goethite and Mn-oxides). Chabazite-Na, gmelinite-Ca, gonnardite-Na, phillipsite-Na and phillipsite-K are reported from Haláp Hill for the first time. The Ca-rich and Na-rich zeolites and abundant calcite were produced by hydrothermal alteration. Mineral assemblages were characterized by X-ray diffraction, differential thermal analysis, energy-dispersive spectrometry and wavelength-dispersive spectrometry. The secondary mineral assemblages were probably formed as a result of low-temperature hydrothermal activity at 50—100°C. Miarolitic minerals crystallized first in cavities in the basalt; they were followed by zeolite-group minerals and calcite. Analcime and phillipsite with or without chabazite/gmelinite/garronite or gobbinsite were the first zeolite-group minerals to crystallize; gonnardite-Na and natrolite crystallized later from Na-rich fluids. Calcite and smectite-group minerals crystallized continually. This paragenetic sequence is similar to others which have been reported in basalt from other localities in the Balaton Highland, Iceland and Northern Ireland.

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 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.

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.

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.

scholarly journals Quartz Crystallite Size and Moganite Content as Indicators of the Mineralogical Maturity of the Carboniferous Chert: The Case of Cherts from Eastern Asturias (Spain)

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallite Size ◽  
Archaeological Sites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Infrared And Raman Spectroscopy ◽  
First Time ◽  
Geological Formations

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.

scholarly journals First Report on the Geologic Occurrence of Natural Na–A Zeolite and Associated Minerals in Cretaceous Mudstones of the Paja Formation of Vélez (Santander), Colombia

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Carlos Alberto Ríos-Reyes ◽  
German Alfonso Reyes-Mendoza ◽  
José Antonio Henao-Martínez ◽  
Craig Williams ◽  
Alan Dyer
Keyword(s):  
Natural Zeolite ◽  
Scanning Electron Micrographs ◽  
Total Sulfur ◽  
Zeolite A ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Phases ◽  
The World ◽  
Porosity And Permeability ◽  
First Time

This study reports for the first time the geologic occurrence of natural zeolite A and associated minerals in mudstones from the Cretaceous Paja Formation in the urban area of the municipality of Vélez (Santander), Colombia. These rocks are mainly composed of quartz, muscovite, pyrophyllite, kaolinite and chlorite group minerals, framboidal and cubic pyrite, as well as marcasite, with minor feldspar, sulphates, and phosphates. Total organic carbon (TOC), total sulfur (TS), and millimeter fragments of algae are high, whereas few centimeters and not biodiverse small ammonite fossils, and other allochemical components are subordinated. Na–A zeolite and associated mineral phases as sodalite occur just beside the interparticle micropores (honeycomb from framboidal, cube molds, and amorphous cavities). It is facilitated by petrophysical properties alterations, due to processes of high diagenesis, temperatures up to 80–100 °C, with weathering contributions, which increase the porosity and permeability, as well as the transmissivity (fluid flow), allowing the geochemistry remobilization and/or recrystallization of pre-existing silica, muscovite, kaolinite minerals group, salts, carbonates, oxides and peroxides. X-ray diffraction analyses reveal the mineral composition of the mudstones and scanning electron micrographs show the typical cubic morphology of Na–A zeolite of approximately 0.45 mμ in particle size. Our data show that the sequence of the transformation of phases is: Poorly crystalline aluminosilicate → sodalite → Na–A zeolite. A literature review shows that this is an unusual example of the occurrence of natural zeolites in sedimentary marine rocks recognized around the world.

scholarly journals The Effect of Surfactant-Modified Montmorillonite on the Cross-Linking Efficiency of Polysiloxanes

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2623
Author(s):  
Monika Wójcik-Bania ◽  
Jakub Matusik
Keyword(s):  
Total Pore Volume ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Cross ◽  
Chain Lengths ◽  
First Time ◽  
Substituent Influence ◽  
Benzyl Substituent

Polymer–clay mineral composites are an important class of materials with various applications in the industry. Despite interesting properties of polysiloxanes, such matrices were rarely used in combination with clay minerals. Thus, for the first time, a systematic study was designed to investigate the cross-linking efficiency of polysiloxane networks in the presence of 2 wt % of organo-montmorillonite. Montmorillonite (Mt) was intercalated with six quaternary ammonium salts of the cation structure [(CH3)2R’NR]+, where R = C12, C14, C16, and R’ = methyl or benzyl substituent. The intercalation efficiency was examined by X-ray diffraction, CHN elemental analysis, and Fourier transform infrared (FTIR) spectroscopy. Textural studies have shown that the application of freezing in liquid nitrogen and freeze-drying after the intercalation increases the specific surface area and the total pore volume of organo-Mt. The polymer matrix was a poly(methylhydrosiloxane) cross-linked with two linear vinylsiloxanes of different siloxane chain lengths between end functional groups. X-ray diffraction and transmission electron microscopy studies have shown that the increase in d-spacing of organo-Mt and the benzyl substituent influence the degree of nanofillers’ exfoliation in the nanocomposites. The increase in the degree of organo-Mt exfoliation reduces the efficiency of hydrosilylation reaction monitored by FTIR. This was due to physical hindrance induced by exfoliated Mt particles.

scholarly journals A novel and potentially scalable CVD-based route towards SnO2:Mo thin films as transparent conducting oxides

2021 ◽  
Author(s):  
Tianlei Ma ◽  
Marek Nikiel ◽  
Andrew G. Thomas ◽  
Mohamed Missous ◽  
David J. Lewis
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Mixed Valence ◽  
Chemical Vapour ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conducting Oxides ◽  
Valence States ◽  
3 Omega ◽  
First Time

AbstractIn this report, we prepared transparent and conducting undoped and molybdenum-doped tin oxide (Mo–SnO2) thin films by aerosol-assisted chemical vapour deposition (AACVD). The relationship between the precursor concentration in the feed and in the resulting films was studied by energy-dispersive X-ray spectroscopy, suggesting that the efficiency of doping is quantitative and that this method could potentially impart exquisite control over dopant levels. All SnO2 films were in tetragonal structure as confirmed by powder X-ray diffraction measurements. X-ray photoelectron spectroscopy characterisation indicated for the first time that Mo ions were in mixed valence states of Mo(VI) and Mo(V) on the surface. Incorporation of Mo6+ resulted in the lowest resistivity of $$7.3 \times 10^{{ - 3}} \Omega \,{\text{cm}}$$ 7.3 × 10 - 3 Ω cm , compared to pure SnO2 films with resistivities of $$4.3\left( 0 \right) \times 10^{{ - 2}} \Omega \,{\text{cm}}$$ 4.3 0 × 10 - 2 Ω cm . Meanwhile, a high transmittance of 83% in the visible light range was also acquired. This work presents a comprehensive investigation into impact of Mo doping on SnO2 films synthesised by AACVD for the first time and establishes the potential for scalable deposition of SnO2:Mo thin films in TCO manufacturing. Graphical abstract

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