Origin of Clays

Clays and clay minerals occur under a fairly limited range of geologic conditions. The environments of formation include soil horizons, continental and marine sediments, geothermal fields, volcanic deposits and weathering rock formations. Most clay minerals form where rocks are in contact with water, air or steam. For example, weathering boulders on a hillside, sediments on sea or lake bottoms, deeply buried sediments containing pore water, and rocks in contact with water heated by magma. Extensive alteration of rocks to clay minerals can produce relatively pure clay deposits that are of economic interest. 

Erosion The transport and deposition of clays and clay minerals produced by 

Sedimentary Low energy Low temperature Medium energy Low temperature High energy Low temperature 

Weathering Low energy Medium temperature Medium energy Medium temperature High energy Medium temperature 

Diagenetic- Low energy Medium energy High energy 

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McMurtry G. M., Wang C.-H., and Yeh H.-W. (1983) Chemical and isotopic investigations into the origin of clay minerals from the Galapagos hydrothermal mounds field. Geochim. Cosmochim. Acta 47, 475-489. 

Righi D. and Meunier A. (1995) Origin of clays by rock weathering. In Origin and Mineralogy of Clays (ed. B. Velde). Springer, pp. 43-161 (334pp.). 

Hillier, S., 1995. Erosion, sedimentation and sedimentary origin of clays. In Velde, B. (ed) Origin and mineralogy of clays. Springer Verlag, Berlin, Heidelberg, New York, pp 162-219. 

Cherniak DJ (2001) Rare earth element diffusion in apatite. Geochim Cosmochim Acta 64 3871-3885 Cherniak DJ, Watson EB, Harrison TM, Grove M (2000) Pb diffusion in monazite A progress report on a combined RBS/SIMS study. EOS Trans Am Geophys Union 8LS25 Copeland RA, Frey FA, Wones DR (1971) Origin of clay nunerals in a mid-Atlantic ridge sediment. Earth Planet Sci Lett 10 186-192... 

To understand the role of clays in nature and their beneficial effects, it is important to have the preliminary knowledge about origin of clays and their transformation in nature. 

Velde, B., and A. Meunier. 2008. The Origin of Clay Minerals in Soils and Weathered Rocks. Berlin Springer. 

The genetic heritage and origin of clay minerals have been described by many research groups, including Esquevin (1958), Millot (1970), Velde (1977), and Eberl (1984) and, most recently, Velde and Meunier (2008). Three basic genetic mechanisms were found to be operational inheritance neoformation and transformation ... 

Velde, B. (1977) Clays and Clay Minerals in Natural and Synthetic Systems. Developments in Sedimentology, vol. 21, Elsevier, Amsterdam, Oxford, New York Velde, B. and Meunier, A. (2008) The Origin of Clay Minerals in Soils and Weathered Rocks, Springer, Heidelberg, New York, ISBN 978-3-540-75633-0. 406 pp. von Chiari, B. and Hennicke, H.W. (1986) Das Trockenverhalten plastischer keramischer Massen, Teil 1. Keram. Z.,... 

Because the crystal structure of clay minerals plays a very large role in determining the way a clay will interact with aqueous solutions, a review of clay mineral surface chemistry must, by necessity, begin with a brief outline of the chemical origins of clay mineral structures. From this basis we will outline the role of edge-site chemical interactions and, subsequently, the controls on ion exchange. This overview of clay chemistry will conclude with a survey outlining how the various site interactions determine the macroscopic behavior of a number of elays in natural systems. 

The original acid—clay developers have been largely replaced by phenohc compounds, such as para-substituted phenohc novolaks. The alkyl group on the phenohc ring is typically butyl, octyl, nonyl, or phenyl. The acidity is higher than that of a typical unsubstituted novolak because of the high concentration of 2,2 -methylene bridges. 

The original pillared clays were made by (/) mixing smectite with a polymeric cationic hydroxy metal complex such as aluminum chlorhydrol (2) allowing a minimal amount of time for the cationic hydroxy metal complex to exchange with the interlayer cations and (7) calcining the resulting material to decompose the hydroxy metal complex (110). A number of newer methods have been developed to make pillared clays (111—117). 

W. D. KeUer, "Processes of Origin of the Clay Minerals," Proceedings of the Soil Clay Mineral Institute, Virginia Polytechnic Institute, Blacksburg, Va., 1962. 

Ore deposits associated with volcanic rocks generally exhibit polymetallic (Cu, Pb, Zn, Sn, W, Au, Ag, Mo, Bi, Sb, As and In) mineralization. Sulfur isotopic values of sulfides from these deposits are close to 0%o, suggesting a deep-seated origin of the sulfide sulfur. Clay deposits (pyrophyllite, sericite and kaolinite) are associated with both felsic volcanic rocks and ilmenite-series granitic rocks of late Cretaceous age in the San-yo Belt. 

Shimoda, S., Kohyama, N. and Ichikawa, Y. (1974) Some problem on the origin of interstratified mica clay minerals. J. Mineral. Soc. Japan, 11, 169-179. 

Rare earth abundance patterns, particularly of the clay fraction, may also help determine the origin of the terrestrial components. Rare earth patterns in clay fractions of sediments tend to inherit the patterns of the rocks from which they originated [24]. In figure 2 are shown several samples of the rare earth abundance patterns of nitric-acid-insoluble residues from the Danish boundary layer and the limestones above and below. Such patterns along with the other chemical data may indicate the... 

Polyelectrolytes provide excellent stabilisation of colloidal dispersions when attached to particle surfaces as there is both a steric and electrostatic contribution, i.e. the particles are electrosterically stabilised. In addition the origin of the electrostatic interactions is displaced away from the particle surface and the origin of the van der Waals attraction, reinforcing the stability. Kaolinite stabilised by poly(acrylic acid) is a combination that would be typical of a paper-coating clay system. Acrylic acid or methacrylic acid is often copolymerised into the latex particles used in cement sytems giving particles which swell considerably in water. Figure 3.23 illustrates a viscosity curve for a copoly(styrene-... 

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