Weathering of the primary rock-forming minerals: processes, products
Banfield, J.F. & Murakami, T. (1998) Atomic resolution transmission electron microscope evidence for the mechanism by which chlorite weathers to 1:1 semir e g u l a r chlorite–vermiculite. American Mineralogist, 83, 348–357.CrossRef Google Scholar
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Weathering of Chlorite in a Quartz-Chlorite Schist: I.
The transformation of chlorite to vermiculite is chemically characterized by an Fe and Mg loss with a slight decrease in the Al/Si ratio. Mg continues to be released throughout the weathering. Fe minerals formed through chlorite weathering are located between chlorite and vermiculite domains (a few μm in size) at first, and then …
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Does calcium carbonate influence clay mineral …
The studied soils did not contain mica-vermiculite minerals, which indicated that dioctahedral vermiculite formed rather at the expense of chlorite than mica. Formation of vermiculite at the expense of chlorite is a commonly reported process for trioctahedral species (e.g., Adams and Kassim 1983; Argast 1991; Bain 1977; Murakami …
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The Geology of Vermiculite Occurrences | Clays and Clay …
Vermiculite in mixed-layer association with biotite, phlogopite, and chlorite is likewise believed to be of supergene origin. Article PDF. Download to ... (this volume) Formation of dioctahedral vermiculite in ia soils: This volume. Ross, C. S. and Shannon, E. V. (1926) Nickeliferous vermiculite and serpentine from Webster, North Carolina ...
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Vermiculite | SpringerLink
Vermiculite is a hydrous 2:1 phyllosilicate similar in structure to mica, but has a lower layer charge, and contains hydrated exchangeable cations in the interlayers versus "non …
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Experimental alteration of Mg-vermiculite under
The hydrothermal reactivity of a Mg-vermiculite from Santa Olalla (Spain) was studied experimentally at 150 and 300°C, 75 and 100 bars, respectively, in (Na, K, Ca, Mg) chloride and sulphate solutions (liquid/solid ratio = 10). The formation of mixed-layer clays is demonstrated by FT-IR spectroscopy, X-ray diffraction (XRD) and electron ...
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Weathering of Chlorite and Vermiculite in Ultramafic …
Chloritic veins in serpentinite and their weathering products were analyzed by X-ray powder diffraction (XRD) and X-ray fluorescence spectrometry (XRF). Chlorite formed during the Hercynian-age orogenesis had apparently been partly transformed to high-charge vermiculite during subsequent metamorphism of the rocks. The idealized structural …
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Chlorite (Mineral)
Clay Mineralogy and Chemistry. William Bleam, in Soil and Environmental Chemistry (Second Edition), 2017. 3.4.5 Layer Structure of Chlorite Group Minerals. X-ray diffraction identifies two clay minerals with a characteristic 1.4 nm layer spacing: the chlorite mineral group and a hydroxy-interlayered vermiculite or smectite.Hydroxy- interlayered smectite …
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Clay Mineralogy | SpringerLink
Fine-grained illite, chlorite, and vermiculite can be formed via mild weathering of primary aluminosilicate minerals, whereas kaolinite and residual metal oxides/hydroxides are typically produced by intense weathering . Intermediate weathering conditions lead to formation of smectite (montmorillonite ).
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Weathering of Chlorite: II. Reactions and Products in …
Weathering of chlorite adjacent to macro- and micro-passages (fissures) in regolith units has been studied to determine the alteration mechanisms and products and compare them to those that prevail at a distance from the open passages. The micro-fissures in the saprolith units evolve as a function of weathering with an increase in micro …
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Weathering of chlorite from grain to watershed: The role …
Experimental Alteration of a Chlorite into a Regularly Interstratified Chlorite-Vermiculite by Chemical Oxidation journal, January 1976. Ross, G. J. Clays and Clay Minerals, Vol. 24, Issue 4; ... (Marcellus Formation) in the Ridge and Valley Appalachians in Pennsylvania, U.S.A. Consistent with the low erosion rate of the landscape, we ...
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Weathering Studies. 1. New Data on Vermiculite
portant change in vermiculite occurs gradually, becoming quite marked above 3000; this change leads to a redistribution of the mica-layer Mg21 and the formation of a "chlorite …
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Distinction of Vermiculite, Chlorite and Montmorillonite in …
Abstract. THE frequency with which vermiculitic and chloritic minerals as well as montmorillonites probably occur in soil-clays makes it necessary to have a clear-cut method for distinguishing ...
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Complexity of clay mineral formation during 120,000 …
Irrespective of site age, mica and chlorite were the dominant clay minerals. During weathering, a remarkable suite of transitional …
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10.5: Clay Minerals
Some other T-O-T clays include smectite, talc and chlorite. Figure 10.5.3 A Representation of the Tetrahedral-Octahedral-Tetrahedral Structure of the 2:1 Clay Mineral Illite The potassium cations (K + ) of illite are held in place because the upper and lower surface of each layer is saturated with oxygen ions (O -2 ) giving these surfaces a ...
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WEATHERING OF CHLORITE AND VERMICULITE IN …
1985) of soil formation on serpentinite in Cabo Ortegal (northwestern Spain), macroscopic chlorite was found ... mation of chlorite/vermiculite was the result of chem- 263 . 264 Buurman, Meijer, ...
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Vermiculite
The heating test can be used to detect vermiculite in the presence of chlorite. ... Formation and Properties of Clay-Polymer Complexes. B.K.G. Theng, in Developments in Clay Science, 2012. 1.1.2.3 Mica, Illite and Chlorite. Like vermiculite, macroscopic forms of (true) mica and chlorite are rarely found in soils, if at all. However, fine ...
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Randomly interstratified illite–vermiculite from weathering of …
As shown by many examples in the literature, biotite is the primary phyllosilicate most vulnerable against vermiculitization which passes through interstratified chlorite-vermiculite into ...
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Chlorite Vermiculitization and Pyroxene Etching in an …
Weathering has etched and deeply-denticulated the constituent orthopyroxenes, and chlorite has been transformed to vermiculite in the upper 3 m of …
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Clay mineral
For interstratified structures of three component layers, structures consisting of illite/chlorite/smectite and illite/vermiculite/smectite have been reported. Because certain interstratified structures are known to be stable under relatively limited conditions, their occurrence may be used as a geothermometer or other geoindicator.
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Smectite group | SpringerLink
Smectite, also known as "swelling clay", is a diverse group of clay minerals with a 2:1 layer silicate structure that can expand and contract upon wetting and drying. All 2:1 layer silicates (which also include illite/mica, chlorite, and vermiculite groups) have 2 tetrahedral sheets surrounding a central octahedral sheet. Smectite 2:1 ...
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TEM image of chlorite weathering from saprock. (a) Chlorite
The formation of such ferruginous clay nodules is explained by alteration of biotite to vermiculite with goethite [112] or alteration of biotite to chlorite/vermiculite [114], and alteration of ...
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Experimental Alteration of a Chlorite into a Regularly
A IIb orthochlorite (brunsvigite), from the chloritic metabasalt in the Middletown Valley of Maryland, was altered to a regularly interstratified chlorite—vermiculite after four months reaction in saturated bromine water on the steambath. The artificial weathering product resembles the regularly interstratified chlorite—vermiculite in a soil in Adams …
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10.5: Clay Minerals
Vermiculite: 2:1 (Mg, Fe 2+, Fe 3+) 3 ((Al, Si) 4 O 10)(OH) 2 ∙ 4H 2 O : Talc: 2:1: Mg 3 Si 4 O 10 (OH) 2 : Chlorite: 2:1 (Mg, Fe) 3 (SI, Al) 4 O 10 (OH) 2 ∙ (Mg, Fe) 3 …
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Weathering of chlorite and some associations of trace elements …
Many mineralogists studied its weathering pathways under different geochemical environments. One common pathway was the dissolution of chlorite to leave either no solid products or only noncrystalline silica (Adams et al., 1971; Bain, 1977; Berthelin and Belgy, 1979), another route was its alteration to vermiculite accompanied …
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Clay-Mineral Formation in Soils Developed in the …
The formation of both vermiculite and smectite at the expense of chlorite was observed in the soils studied. The transformation probably led to smectite formation via intermediate stages of mixed-layer minerals (i.e. chlorite-vermiculite, chlorite-smectite, and/or vermiculite-smectite). The process of chlorite dissolution took place ...
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Weathering of Chlorite: I. Reactions and Products in …
The alteration of chlorite to vermiculite was characterized by the loss of Mg and Fe and minor Al, all ions considered to be lost from the brucite-like sheet of chlorite. ... Cho, H.D. and Mermut, A.R. (1992) Evidence for halloysite formation from weathering of ferruginous chlorite. Clays and Clay Minerals, 40, 608–619. Article Google Scholar
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Evidence for Halloysite Formation from Weathering of Ferruginous Chlorite
Evidence of chlorite weathering to halloysite appears to be limited. Trioctahedral ferruginous chlorite occurring in granitic rocks and in situ altered phases isolated from the horizons of two soils in southern Korea were studied by scanning and transmission electron microscope (SEM, TEM), chemical, and X-ray diffraction (XRD) …
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Experimental alteration of Mg-vermiculite under …
Experimental alteration of Mg-vermiculite under hydrothermal conditions: formation of mixed-layered saponite-chlorite minerals - Volume 38 Issue 3 ... vermiculite chlorite saponite XRD microprobe data FT-IR. Type Research Article. Information Clay Minerals, Volume 38, Issue 3, September 2003, pp. 303 - 314.
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USGS OFR01-041: Mixed-layer clays
Commonly described mixed-layer clays include: illite-vermiculite, illite-smectite, chlorite-vermiculite (corrensite), chlorite-smectite, and kaolinite-smectite. Mixed-layer clays can form by weathering involving the …
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