Argillation of Three Silicate Rocks Expressed in Terms of Ion Transfer
The transfer of ions during the weathering of a Medford diabase, a granite from British Guiana, and of the Cheto Arizona tuff is traced by recasting the analyses of the fresh rocks and their altered counterparts into 160-oxygen rock cells, and by comparing algebraically the products of the weathering reaction with the original reactants.
Hydrolysis and hydration are the first steps in the reaction. H ions were added in the weathering environment of the diabase and granite, but Mg ions were added in the change of tuff to bentonite.
Silica and alkali metal ions are dissolved and removed during weathering of the diabase and granite, presumably under acid conditions, but it appears that the Cheto tuff was formed under a non-acid environment where Mg was added. During the hydrolysis of silicate rocks, H ions are concentrated temporarily in the clay minerals on land, while OH ions go to the ocean.
More examples of ion transfer during weathering than the three given herein are needed to define the reactions occurring in the many environments of alteration which rocks encounter.
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- Frederickson, A. F., and Cox, J. E. (1954) “Solubility” of albite in hydrothermal solutions: Am. Mineral., vol. 39, pp. 738–750.Google Scholar
- Harrison, J. B. (1933) The katamorphism of igneous rocks under humid tropical conditions: Imperial Bureau of Soil Science, Rothamstead Experimental Station, Harpenden, England.Google Scholar
- Haseman, J. F., and Marshall, C. E. (1945) The use of heavy minerals in studies of the origin and development of soils: Univ. Mo. Agr. Exp. Sta. Research Bull. 387, 75 pp.Google Scholar
- Keller, W. D. (1952) Analcime in the Popo Agie member of the Chugwater formation: Jour. Sed. Pet., pp. 70–82.Google Scholar
- Keller, W. D. (1955) The principles of chemical weathering: Lucas Brothers, Columbia, Mo., 88 pp.Google Scholar
- Leith, C. K., and Mead, W. J. (1915) Metamorphic geology: Henry Holt & Co., New York, 337 pp.Google Scholar
- Millot, Georges (1949) Relations entre la constitution et la genèse des roches sédimentaires argileuses: Bull. L’Assoc. Ingén. Géol., Univ. Naticy, Tome III, 352 pp.Google Scholar
- Nutting, P. G. (1943a) Adsorbent clays: Their distribution, properties, production, and uses: U.S. Geol. Sur. Bull., vol. 928, pp. 127–221.Google Scholar
- Nutting, P. G. (1943b) The action of some aqueous solutions on clays of the montmorillonite group: U.S. Geol. Sur. Prof. Paper 197-F, pp. 217–233.Google Scholar
- Ross, C. S. (1943) Clays and soils in relation to geologic processes: Jour. Wash. Acad. Sci., vol. 33, pp. 225–235.Google Scholar