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Replacement of Quartz by Opaline Silica during Weathering of Petrified Wood

Published online by Cambridge University Press:  02 April 2024

A. L. Senkayi
Affiliation:
Department of Soil and Crop Sciences Texas Agricultural Experiment Station, Texas A&M University, College Station, Texas 77843
J. B. Dixon
Affiliation:
Department of Soil and Crop Sciences Texas Agricultural Experiment Station, Texas A&M University, College Station, Texas 77843
L. R. Hossner
Affiliation:
Department of Soil and Crop Sciences Texas Agricultural Experiment Station, Texas A&M University, College Station, Texas 77843
B. P. K. Yerima
Affiliation:
Department of Soil and Crop Sciences Texas Agricultural Experiment Station, Texas A&M University, College Station, Texas 77843
L. P. Wilding
Affiliation:
Department of Soil and Crop Sciences Texas Agricultural Experiment Station, Texas A&M University, College Station, Texas 77843
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Abstract

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A mineralogical investigation by X-ray powder diffraction and optical, scanning, and transmission electron microscopy of partially weathered petrified wood in the Yegua Formation (Eocene) of east-central Texas revealed that microcrystalline quartz present in the unaltered petrified wood has been gradually dissolved and replaced by disordered silica polymorphs (mainly opal-CT) as a result of weathering. This replacement suggests that the reaction sequence: opal-A → opal-CT → quartz, which has been described elsewhere to occur during diagenetic alteration of petrified wood, is apparently reversed when the petrified wood is exposed to low-energy weathering conditions. The relatively high rate of dissolution of the quartz in the petrified wood appears to be related to its small crystallite size. The silica released by the dissolution of the quartz is subsequently reprecipitated as disordered cristobalite-tridymite (opal-CT) and poorly crystalline silica (opal-A) that, in turn, probably converts to opal-CT on aging. Opal-CT is the major silica phase in the completely altered powdery material enclosing the partially weathered petrified wood. The intermediate zone between the altered and unaltered zones contains both quartz and opal-CT.

Type
Research Article
Copyright
Copyright © 1985, The Clay Minerals Society

References

Berg, R. R. and Berg, R. R., 1970 Stratigraphy of the Claiborne Group Claiborne Outcrops in the Brazos Valley, Southwest Texas 1316.Google Scholar
Buurman, P., 1972 Mineralization of fossil wood Scripta Geol. 12 143.Google Scholar
Jackson, M. L., 1974 Soil Chemical Analysis-Advanced Course 2nd Madison, Wisconsin published by the author.Google Scholar
Jones, J. B. and Segnit, E. R., 1971 The nature of opal. I. Nomenclature and constituent phases Geol. Soc. Aust. J. 18 5768.CrossRefGoogle Scholar
Jones, J. B. and Segnit, E. R., 1972 Genesis of cristobalite and tridymite at low temperatures Geol. Soc. Aust. J. 18 419422.CrossRefGoogle Scholar
Kovnurko, G. M., 1970 Calcite, a-cristobalite and quartz in zoned chert concretions Dokl. Akad. Nauk 195 169170.Google Scholar
Lidstrom, L. (1968) Surface and bond-forming properties of quartz and silicate minerals and their application in mineral processing techniques: Acta Polytech. Scand. Chem. Includ. Metall. Ser. 75, 149 pp.Google Scholar
Mathews, A. L. (1950) Geology of Brazos County, Texas: Texas A&M College, Eng. Exp. Station, Res. Rept. 14, 14 pp.Google Scholar
Mizutani, S., 1977 Progressive ordering of cristobalitic silica in the early stage of diagenesis Contrib. Mineral. Petrol. 61 129140.CrossRefGoogle Scholar
Pollard, C. O. Jr. and Weaver, C. E., 1973 Opaline spheres: loosely packed aggregates from silica nodule in diatoma-ceous Miocene fuller’s earth J. Sediment. Petrol. 43 10721076.Google Scholar
Scurfield, G. and Segnit, E. R., 1984 Petrifaction of wood by silica minerals Sediment. Geol. 39 149167.CrossRefGoogle Scholar
Senkayi, A. L., Dixon, J. B., Hossner, L. R., Abder-Ruhman, M. and Fanning, D. S., 1984 Mineralogy and genetic relationships of tonstein, bentonite, and lignitic strata in the Eocene Yegua Formation of east-central Texas Clays & Clay Minerals 32 259271.CrossRefGoogle Scholar
Stein, C. L., 1982 Silica recrystallization in petrified wood J. Sediment. Petrol. 52 12771282.Google Scholar
Wilding, L. P., Smeck, N. E., Drees, L. R., Dixon, J. B. and Weed, S. B., 1977 Silica in soils: quartz, cristobalite, tridymite, and opal Minerals in Soil Environments Madison, Wisconsin Soil Sci. Soc. Amer. 471552.Google Scholar