Geochemistry and halmyrolysis of clay minerals, Rio Ameca, Mexico
TL;DR: In this article, a study of the chemical interactions between river clays and sea water was conducted for the purpose of studying the properties of the major cations of the river clay and its interaction with sea water.
About: This article is published in Geochimica et Cosmochimica Acta.The article was published on 1970-08-01. It has received 78 citations till now. The article focuses on the topics: Clay minerals & Illite.
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TL;DR: The relationship between the redox state of deposition, early diagenesis, and pore water chemistry is investigated in this paper, where a diagenetic model is used to predict the measured interstitial water concentrations of alkalinity, ammonia and phosphate from reactions involving the decomposition of organic material by the reduction of pore waters SO42− and the authigenic precipitation of CaCO3.
280 citations
TL;DR: In this article, it was shown that most of the dolomite formed within a few tens of meters of the sea floor within the zone of microbial sulfate reduction, and the distribution coefficient of strontium in Dolomites was determined to have an average value of 0.06.
Abstract: Dolomite is presently forming throughout a large part of the oceans in continental margin marine sediments accumulating at rates less than 500 m/m.y. and having organic carbon contents greater than 0.5 wt. %. At higher sedimentation rates, the dolomite content of the sediments is greatly diluted. At lower organic carbon content, the porewater chemistry precludes dolomite formation. The reactants for dolomite formation have the following sources: magnesium supplied from overlying seawater, calcium supplied by the dissolution of calcium carbonate, and carbon supplied from carbonate dissolution and organic carbon oxidation. The rate of dolomite formation appears to be limited by the rate of calcium carbonate dissolution. This rate can be quantitatively calculated from the magnesium diffusional and advective fluxes. Conversely, in ancient sediments the depth and timing of dolomite formation can be calculated from the amount of dolomite and the sedimentation rate. In dolomite-rich sediments these calculations demonstrate that most of the dolomite formed within a few tens of meters of the sea floor within the zone of microbial sulfate reduction. Such dolomites have ne ative values of ^dgr13C. Dolomite in dolomite-poor sediments may form at greater burial depth, below the zone of sulfate reduction, resulting in positive values of ^dgr13C. The distribution coefficient of strontium in dolomite has been determined to have an average value of 0.06. Using this value, predicted strontium contents for submarine dolomites range from 150 ppm in dolomite-rich sections to 1,290 ppm in dolomite-poor sections.
248 citations
TL;DR: In this paper, the mild 1% Na2CO3 alkaline leach procedure commonly used to estimate biogenic silica was modified to include an initial mild leach step with 0.1N HCl to remove metal oxide coatings and to activate poorly crystalline authigenic phases for alkaline dissolution.
230 citations
TL;DR: Water adsorption on kaolinite, illite, and montmorillonite clays was studied as a function of relative humidity at room temperature using horizontal attenuated total reflectance (HATR) Fourier transform infrared (FTIR) spectroscopy equipped with a flow cell and it was suggested that different properties drive water Adsorption under different adsorptive regimes resulting in the broad variability of water uptake mechanisms.
Abstract: Water adsorption on kaolinite, illite, and montmorillonite clays was studied as a function of relative humidity (RH) at room temperature (298 K) using horizontal attenuated total reflectance (HATR) Fourier transform infrared (FTIR) spectroscopy equipped with a flow cell. The water content as a function of RH was modeled using the Brunauer, Emmett, and Teller (BET) and Freundlich adsorption isotherm models to provide complementary multilayer adsorption analysis of water uptake on the clays. A detailed analysis of model fit integrity is reported. From the BET fit to the experimental data, the water content on each of the three clays at monolayer (ML) water coverage was determined and found to agree with previously reported gravimetric data. However, BET analysis failed to adequately describe adsorption phenomena at RH values greater than 80%, 50%, and 70% RH for kaolinite, illite, and montmorillonite clays, respectively. The Freundlich adsorption model was found to fit the data well over the entire range of...
202 citations
TL;DR: Within compacting mudstone sequences several depth zones can be recognized in which distinctive diagenetic reactions take place as discussed by the authors, most striking are those involving carbonate precipitation or replacement, and these reactions drastically modify the permeability of both potential source and reservoir rocks.
Abstract: Within compacting mudstone sequences several depth zones can be recognised in which distinctive diagenetic reactions take place. Most striking are those involving carbonate precipitation or replacement. The major carbon source is organic matter which is degraded by various microbiological and inorganic reactions to bicarbonate as one product. Other reactions involving silicates and sesquioxides introduce cations to the porewater system and carbonates are precipitated. Their chemical and isotopic composition can be linked with temperature and depth of formation. Analysis of some of the literature of sandstone diagenesis suggests that carbonate cements in sandstones often originate in mudstones, and that precipitation may take place far from the site of solute generation. Vast volumes of porewater excluded from mudstones during compaction are channelled into and travel great distances within sand units. Early diagenetic reactions drastically modify the permeability of both potential source and reservoir rocks. The component of horizontal flow is greatly increased and this must affect later migration of liquid hydrocarbons.
189 citations
References
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Book•
01 Jan 1958
TL;DR: I: Geochemistry of Crystal Phases 1: Elemental Properties and Crystal Chemistry 2: Concepts of Chemical Thermodynamics 3: Thermochemistry of Crystalline Solids 4: Some Concepts of Defect Chemistry 5: Silicates II: Geochemical of Silicate Melts 6: SilicateMelts 7: Introduction to Petrogenetic Systems III: Geochemics of Fluids 8: Geography of Aqueous Phases 9: Chemical Chemistry of Gaseous Phasing IV: Methods 10: Trace Element Geochemistry 11: Isotope Geochemistry Appendix 1:
Abstract: I: Geochemistry of Crystal Phases 1: Elemental Properties and Crystal Chemistry 2: Concepts of Chemical Thermodynamics 3: Thermochemistry of Crystalline Solids 4: Some Concepts of Defect Chemistry 5: Silicates II: Geochemistry of Silicate Melts 6: Thermochemistry of Silicate Melts 7: Introduction to Petrogenetic Systems III: Geochemistry of Fluids 8: Geochemistry of Aqueous Phases 9: Geochemistry of Gaseous Phases IV: Methods 10: Trace Element Geochemistry 11: Isotope Geochemistry Appendix 1: Constants, Units and Conversion Factors Appendix 2: Review of Mathematics
2,060 citations
TL;DR: In this article, the relative abundances of montmorillonite, illite, kaolinite, chlorite, gibbsite, pyrophyllite, mixed-layer clay minerals, feldspars, and dolomite were determined.
Abstract: Semiquantitative mineral analysis has been done by X-ray diffraction on the < 2 μ- and 2–20 μ-size fractions of approximately five hundred Recent deep-sea core samples from the Atlantic, Antarctic, western Indian Oceans, and adjacent seas. Relative abundances of montmorillonite, illite, kaolinite, chlorite, gibbsite, quartz, amphibole, clinoptilolite-heulandite(?), and pyrophyllite(?) were determined. Mixed-layer clay minerals, feldspars, and dolomite were also observed but not quantitatively evaluated. From the patterns of mineral distribution, the following conclusions appear warranted:
Most Recent Atlantic Ocean deep-sea clay is detritus from the continents. The formation of minerals in situ on the ocean bottom is relatively unimportant in the Atlantic but may be significant in parts of the southwestern Indian Ocean.
Mineralogical analysis of the fine fraction of Atlantic Ocean deep-sea sediments is a useful indicator of sediment provenance. Kaolinite, gibbsite, pyrophyllite, mixed-layer minerals, and chlorite contribute the most unequivocal provenance information because they have relatively restricted loci of continental origin.
Topographic control over mineral distribution by the Mid-Atlantic Ridge in the North Atlantic Ocean precludes significant eolian transport by the jet stream and emphasizes the importance of transport to and within that part of the deep-sea by processes operative at or near the sediment-water interface.
Transport of continent-derived sediment to the equatorial Atlantic is primarily by rivers draining from South America and by rivers and wind from Africa.
The higher proportion of kaolinite and gibbsite in deep-sea sediments adjacent to small tropical South American rivers reflects a greater intensity of lateritic weathering than is observed near the mouths of the larger rivers. This may be explained by a greater variety of pedogenic conditions in the larger drainage basins, resulting in an assemblage with proportionately less lateritic material in the detritus transported by the larger rivers despite their quantitatively greater influence on deep-sea sediment accumulation.
In the South Atlantic Ocean, the fine-fraction mineral assemblage of surface sediment in the Argentine Basin is sufficiently unlike that adjacent to the mouth of the Rio de la Plata to preclude it as a major Recent sediment source for that basin. The southern Argentine Continental Shelf, the Scotia Ridge, and the Weddell Sea arc mineralogically more likely immediate sources. Transport from the Weddell Sea by the Antarctic Bottom Water may be responsible for the northward transport of fine-fraction sediment along parts of the western South Atlantic as far north as the Equator.
2,001 citations
TL;DR: In this article, the relative amounts of chlorite, montmorillonite, kaolinite and illite in the less than 2 micron size fraction of pelagic sediments are related to the sources and transport paths of solid phases from the continents to the oceans and to injections of volcanic materials to the marine environment.
555 citations