Journal ArticleDOI
Further investigations of a conversion series of dioctahedral mica/smectites in the shinzan hydrothermal alteration area, northeast japan
Atsuyuki Inoue,Minoru Utada +1 more
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A complete conversion series for mica/smectites was found in a hydrothermal alteration envelope around Kuroko-type ore deposits at the Shinzan area, Akita Prefecture, Northeast Japan as discussed by the authors.Abstract:
A complete conversion series for mica/smectites was found in a hydrothermal alteration envelope around Kuroko-type ore deposits at the Shinzan area, Akita Prefecture, Northeast Japan. The minerals are an alteration product of volcanic glass of Miocene age and are commonly associated with zeolites and silica minerals. Degrees of ordering of interstratification of the minerals change discontinuously from Reichweite g = 0 (100–55% expandable layers) to g = 1 (45–20% expandable layers), and from g = 1 to g = 2 (<20% expandable layers). This pattern of conversion differs from the behavior of mica/smectites during burial diagenesis which undergo a continuous change in ordering type, and from the behavior of rectorite which displays a constant expandability and ordering (45–55%) over a wide range of conditions. Differences between these minerals were also found in the relationships between expandability and total layer charge, and between expandability and number of non-exchangeable interlayer cations. In mica/smectites from the Shinzan area, chemical changes in the interlayers and tetrahedral and octahedral sites are consistent with a reaction in which K-enrichment and K-fixation in the interlayers are controlled by an increase in negative layer charge. This conversion occurred in response to a steep geothermal gradient and migrating hydrothermal solutions.read more
Citations
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Journal ArticleDOI
An experimentally derived kinetic model for smectite-to-illite conversion and its use as a geothermometer
TL;DR: In this paper, the authors investigated the kinetics for the con- version of a Na-saturated montmorillonite (SWy-1) to a mixed-layer smectite/iUite as a function of KC1 concentration.
Journal ArticleDOI
Hydrothermal Minerals and Precious Metals in the Broadlands-Ohaaki Geothermal System: Implications for Understanding Low-Sulfidation Epithermal Environments
TL;DR: In this paper, the authors show how peripheral alteration by CO 2 -rich waters relate with propylitic alteration in the presence of a deeply derived chloride water containing ~1,000 mg/kg Cl and ~26,400 mg/ kg CO 2.
Journal ArticleDOI
Transmission and Analytical Electron Microscopy of the Smectite-To-Illite Transition
Juno Ho Ahn,Donald R. Peacor +1 more
TL;DR: In this article, the authors studied the smectite to illite reaction in argillaceous sediments from depths of 1750, 2450, and 5500 m in a Gulf Coast well.
Journal ArticleDOI
Comparison of structural models of mixed-layer illite/smectite and reaction mechanisms of smectite illitization
TL;DR: In this paper, the authors compare the mineralogical and geochemical consequences of several reaction mechanisms for smectite illitization: 1) solid-state transformation (SST), 2) dissolution and crystallization (DC), and 3) Ostwald ripening (OR).
Book ChapterDOI
Formation of Clay Minerals in Hydrothermal Environments
TL;DR: In this article, the formation of clay minerals in such dynamic processes of hydrothermal alteration is discussed, where a pre-existing rock-forming mineral assemblage is altered to a new set of minerals which are more stable under the conditions of temperature, pressure, and fluid composition.
References
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Journal ArticleDOI
Mechanism of burial metamorphism of argillaceous sediment: 1. Mineralogical and chemical evidence
TL;DR: In this paper, a detailed mineralogical and chemical investigation of shale cuttings from a well (Case Western Reserve University Gulf Coast 6) in Oligocene-Miocene sediment of the Gulf Coast of the United States was made by x-ray diffraction.
Book
The chemistry of clay minerals
Charles E. Weaver,Lin D. Pollard +1 more
TL;DR: Rich as mentioned in this paper discusses the relationship of composition to structure of layer silicates of clay and the relationship between weathering and electrochemica reactions to a smal degree in a series of books called "Developments in Sedimentology".
Journal ArticleDOI
Diagenesis of Gulf Coast Clayey Sediments and Its Possible Relation to Petroleum Migration
TL;DR: In this article, the authors established reference intervals in the subsurface on the basis of apparent systematic interlayer water loss of swelling clay minerals, which are present at sufficiently shallow depths to be evident within oil-bearing strata of the Gulf Coast.
Journal ArticleDOI
Burial Diagenesis in Gulf Coast Pelitic Sediments
TL;DR: In this paper, the authors examined surface samples of shales ranging in age from Pleistocene to Eocene obtained from five Gulf Coast oil wells to determine the nature and extent of burial diagenesis in pelitic sediments.
Journal ArticleDOI
The Nature of Interlayering in Mixed-Layer Illite-Montmorillonites
TL;DR: In this paper, the authors investigated the interstratification of mixed-layer illite-montmorillonites by comparison of diffraction patterns with calculated one-dimensional diffraction profiles, taking into account the effects of particle size distribution, chemical composition, and convolution factors.
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