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Microstructures, Formation Mechanisms, and Depth-Zoning of Phyllosilicates in Geothermally Altered Shales, Salton Sea, California

Published online by Cambridge University Press:  02 April 2024

Yu-Chyi Yau ,
Donald R. Peacor ,
Richard E. Beane ,
Eric J. Essene  and
S. Douglas Mcdowell
Yu-Chyi Yau
Affiliation:
Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109
Donald R. Peacor
Affiliation:
Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109
Richard E. Beane*
Affiliation:
Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109
Eric J. Essene
Affiliation:
Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109
S. Douglas Mcdowell
Affiliation:
Department of Geology and Geological Engineering, Michigan Technological University, Houghton, Michigan 49931
*
4Present address: St. Joe American Corporation, 2002 N. Forbes Blvd., Tucson, Arizona 85745.
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Abstract

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Scanning, transmission, and analytical electron microscopy studies of shales from the Salton Sea geothermal field revealed that phyllosilicates progress through zones of illite-muscovite (115°−220°C), chlorite (220°−310°C), and biotite (310°C). These phyllosilicates occur principally as discrete, euhedral to subhedral crystals which partly fill pore space. The structural and chemical heterogeneity, which is typical of phyllosilicates in shales subject to diagenesis, is generally absent. Textures and microstructures indicate that the mineral progression involves dissolution of detrital phases, mass transport through interconnecting pore space, and direct crystallization of phyllosilicates from solution.

Phyllosilicate stability relations indicate that either increase in temperature or changing ion concentrations in solutions with depth are capable of explaining the observed mineral zoning. Textural and compositional data suggest that the observed mineral assemblages and the interstitial fluids approach equilibrium relative to the original detrital suites. The alteration process may have occurred in a single, short-lived, episodic hydrothermal event in which the original detrital phases (smectite, etc.) reacted directly to precipitate illite, chlorite, or biotite at different temperatures (depths) without producing intermediate phases.

Keywords

ChloriteElectron microscopyFluid-mineral equilibriaGeothermal fieldUliteSalton SeaSmectiteTexture
Type
Research Article
Information
Clays and Clay Minerals , Volume 36 , Issue 1 , February 1988 , pp. 1 - 10
Copyright
Copyright © 1988, The Clay Minerals Society

Footnotes

1

Contribution No. 433 from the Mineralogical Laboratory, Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109.

References

Ahn, J. H. and Peacor, D. R., 1985 Transmission electron microscopic study of diagenetic chlorite in Gulf Coast argillaceous sediments Clays & Clay Minerals 33 228 – 237.CrossRefGoogle Scholar
Ahn, J. H. and Peacor, D. R., 1986 A transmission and analytical electron microscopic study of the smectite to illite transition Clays & Clay Minerals 34 165 – 180.Google Scholar
Beane, R. E. and Titley, S. R., 1981 Porphyry copper deposits. Part II. Hydrothermal alteration and mineralization Econ. Geol. 75 238 – 269.Google Scholar
Bird, D.K. and Norton, D.L., 1981 Theoretical predictions of phase relations among aqueous solution and minerals: Salton Sea geothermal system Geochim. Cosmochim. Acta 45 1479 – 1493.CrossRefGoogle Scholar
Bird, D. K., SchifFman, P., Elders, W. A., Williams, A. E. and McDowell, S. C., 1984 Calc-silicate mineralization in active geothermal systems Econ. Geol. 79 671 – 695.CrossRefGoogle Scholar
Bowers, T. S., Jackson, K. J. and Helgeson, H. C., 1984 Equilibrium Activity Diagrams for Coexisting Minerals and Aqueous Solutions at Pressures and Temperatures to 5 Kbar and 600°C New York Springer-Verlag.Google Scholar
Burst, J. F., 1969 Diagenesis of Gulf Coast clay sediments and its possible relation to petroleum migration Amer. Assoc. Petroleum Geol. Bull. 53 73 – 93.Google Scholar
Elders, W. A., 1984 Proposed Scientific Activities for the Salton Sea Scientific Drill Projects .Google Scholar
Ferry, J.M., 1985 A biotite isograd in south-central Maine, U.S.A.: Mineral reactions, fluid transfer, and heat transfer J. Petrol. 25 871 – 893.CrossRefGoogle Scholar
Helgeson, H. C. and Abelson, P. H., 1967 Solution chemistry and metamor-phism Researches in Geochemistry, Vol. 2 New York Wiley 362 – 402.Google Scholar
Helgeson, H. C., 1968 Geologic and thermodynamic characteristics of the Salton Sea Geothermal System Amer. J. Sci. 266 129 – 166.CrossRefGoogle Scholar
Helgeson, H. C., 1969 Thermodynamics of hydrothermal systems at elevated temperatures and pressures Amer. J. Sci. 267 729 – 804.CrossRefGoogle Scholar
Helgeson, H. C., 1970 A chemical and thermodynamic model for ore deposition in hydrothermal systems Mineral. Soc. Amer. Special Paper 3 155 – 186.Google Scholar
Helgeson, H. C., Garrels, R. M. and Mackenzie, F. T., 1969 Evaluation of irreversible reactions in geochemical processes involving minerals and aqueous solutions: II. Applications Geochim. Cosmochim. Acta 32 455 – 482.CrossRefGoogle Scholar
Hemley, J. J., Montoya, J. W., Nigini, A. and Vincent, H. A., 1971 Some alteration reactions in the system CaO-Al2O3-SiO2-H2O Soc. Mining Geol. Japan Spec. Issue 2 58 – 63.Google Scholar
Hoschek, G., 1973 Zur Stabilität metamorpher biotit-pa-ragenesen Tschermaks Mineral. Petrol. Mitt. 20 48 – 58.CrossRefGoogle Scholar
Hower, J., Eslinger, E. V., Hower, M. E. and Perry, E. A., 1976 Mechanism of burial metamorphism of argillaceous sediments: 1. Mineralogical and chemical evidence Geol. Soc. Amer. Bull. 87 725 – 737.2.0.CO;2>CrossRefGoogle Scholar
Isaacs, D., Brown, P. E., Valley, J. W., Essene, E. J. and Peacor, D. R., 1981 An analytical study of a pyroxene-amphibole intergrowth Contrib. Mineral. Petrol. 77 115 – 120.CrossRefGoogle Scholar
Lee, J. H., Peacor, D. R., Lewis, D. D. and Wintsch, R. P., 1984 Chlorite-illite/muscovite interlayered and inter-stratified crystals: A TEM/AEM study Contrib. Mineral. Petrol. 88 372 – 385.CrossRefGoogle Scholar
Lee, J. H., Ahn, J. H. and Peacor, D. R., 1985 Textures in layer silicates: Progressive changes through diagenesis and low temperature metamorphism J. Sed. Petrol. 55 532 – 540.Google Scholar
Maxwell, D. T. and Hower, J., 1967 High-grade diagenesis and low-grade metamorphism of illite in the Precambrian Belt Series Amer. Mineral. 52 843 – 857.Google Scholar
McDowell, S. D. and Elders, W. A., 1980 Authigenic layer silicate minerals in borehole Elmore 1, Salton Sea geothermal field, California, U.S.A. Contrib. Mineral. Petrol. 74 293 – 310.CrossRefGoogle Scholar
McDowell, S. D. and Elders, W. A., 1983 Allogenic layer silicate minerals in borehole Elmore #1, Salton Sea geothermal field, California Amer. Mineral. 68 1146 – 1159.Google Scholar
Montoya, J. W. and Hemley, J. J., 1975 Activity relations and stability in alkalic feldspar and mica alteration reactions Econ. Geol. 70 577 – 583.CrossRefGoogle Scholar
Morton, J. P., 1985 Rb-Sr evidence for punctuated illite/smectite diagenesis in the Oligocene Frio Formation, Texas Gulf Coast Geol. Soc. Amer. Bull. 96 114 – 122.2.0.CO;2>CrossRefGoogle Scholar
Morton, J. P., 1985 Rb-Sr dating of diagenesis and source age of clays in Upper Devonian black shales of Texas Geol. Soc. Amer. Bull. 96 1043 – 1049.2.0.CO;2>CrossRefGoogle Scholar
Muffler, L. P. J. and Doe, B. R., 1968 Composition and mean age of detritus of the Colorado River delta in the Salton trough, southeastern California J. Sed. Petrol. 38 384 – 399.Google Scholar
Muffler, L. P. J. and White, D. E., 1969 Active metamorphism of Upper Cenozoic sediments in the Salton Sea geothermal field and the Salton trough, southeastern California Geol. Soc. Amer. Bull. 80 157 – 182.CrossRefGoogle Scholar
Perkins, D., Essene, E. J. and Wall, V. J., 1987 THERMO: A computer program for calculation of mixed volatile equilibria Amer. Mineral. 72 446 – 447.Google Scholar
Perry, E. and Hower, J., 1970 Burial diagenesis in Gulf Coast pelitic sediments Clays & Clay Minerals 18 165 – 177.CrossRefGoogle Scholar
Robinson, P. T., Elders, W. A. and Muffler, L. P. J., 1976 Quaternary volcanism in the Salton Sea geothermal field, Imperial Valley, California Geol. Soc. Amer. Bull. 87 347 – 360.2.0.CO;2>CrossRefGoogle Scholar
Velde, B. and Hower, J., 1963 Petrological significance of illite polymorphism in Paleozoic rocks Amer. Mineral. 48 1239 – 1254.Google Scholar
Weaver, C. E. and Swineford, A., 1959 The clay petrology of sediments Clays and Clay Minerals, Proc. 6th Natl. Confi, Berkeley, California, 1957 New York Pergamon Press.Google Scholar
Yau, Y. C., Peacor, D. R. and McDowell, S. D., 1987 Smectite-illite reactions in Salton Sea shales J. Sed. Petrol. 57 335 – 342.Google Scholar
Yau, Y. C., Peacor, D. R. and Essene, E. J., 1987 Authigenic anatase and titanite in shales from the Salton Sea geothermal field, California Neues Jahr. Mineral. Monat. 10 441 – 452.Google Scholar
Zen, E.-a., 1959 Clay mineral-carbonate relations in sedimentary rocks Amer. J. Sci. 257 29 – 43.CrossRefGoogle Scholar
Zen, E.-a. and Thompson, A. B., 1974 Low grade regional metamorphism: Mineral equilibrium relations Annual Rev. Earth Planetary Sci. 2 179 – 212.CrossRefGoogle Scholar