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Mineralogy and Origin of the Coalinga Asbestos Deposit

Published online by Cambridge University Press:  01 July 2024

F. A. Mumpton  and
C. S. Thompson
F. A. Mumpton
Affiliation:
Department of The Earth Sciences, State University College, Brockport, New York 14420
C. S. Thompson
Affiliation:
R. T. Vanderbilt Corporation, Norwalk, Connecticut, USA
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Abstract

Since 1960 asbestos production of the United States has more than tripled, a phenomenon due in large part to the development of the Coalinga asbestos deposit in western California. Although most asbestos ores contain 5–10 per cent chrysotile in the form of cross- or slip-fiber veins within massive serpentinite bodies, no such veins are to be found in the Coalinga deposit despite the fact that it contains more than 50 per cent recoverable chrysotile. The Coalinga ore consists of soft, powdery, pellet-like agglomerates of finely matted chrysotile surrounding blocks and fragments of serpentinite rock. The highly sheared and pulverized nature of the ore favors its exploitation by simple, open-pit mining, and high quality products can be prepared by either wet or dry milling processes.

Four types of serpentine material are distinguishable: (1) hard, dense blocks of serpentinite rock, ranging from fractions of an inch to several tens of feet in diameter; (2) tough, leathery sheets, resembling mountain leather, up to several square feet in size; (3) brittle blades and plates of green serpentine, a few square inches in size; and (4) friable agglomerates of soft, powdery chrysotile containing appreciable amounts of the other three. Chrysotile is the principal component of all the above materials, with the exception of the serpentinite rock which consists mainly of lizardite and/or antigorite, with small amounts of brucite, magnetite, and very short fiber chrysotile. Although chrysotile fibers up to several microns in length are present in the leathery sheets, most Coalinga chrysotile is much shorter and arranged in a swirling mesh or disoriented, tangled fibers, much like cellulose fibers in paper. Fragments of serpentinite gangue are scattered throughout the ore and contain most of the lizardite, antigorite, and brucite. Chemical, electron probe, and X-ray analyses confirm the iron-rich nature of the brucite, a critical factor in the susceptibility of this phase to oxidation in the surface weathering zone. Here brucite either dissolves, leaving behind a residue of brown, amorphous iron oxides, or transforms in situ to pyroaurite or coalingite. Dissolved magnesium precipitates as hydromagnesite immediately above the water table throughout the deposit.

The abnormally high chrysotile content of this deposit is probably a result of the intensive shearing that it underwent during or after emplacement. If the friable, chrysotile-rich ore was produced during this pulverization episode, (1) lizardite and/or antigorite in the serpentinite must have been transformed into chrysotile and (2) brucite must have been removed. It is likely that early-formed lizardite/antigorite dissolved in the ground waters which pervaded the highly sheared body and that chrysotile later precipitated from these waters, coating all available surfaces.

Type
Research Article
Information
Clays and Clay Minerals , Volume 23 , Issue 2 , April 1975 , pp. 131 - 143
Copyright
Copyright © 1975, The Clay Minerals Society

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References

Anonymous, , (1957) Proposed wildlife withdrawal—asbestos Mineral Infor. Serv., Cal. Div. Mines 10 6.Google Scholar
Barbaras, G. D., (1953) Aqueous asbestos dispersion and process for producing same U.S. Patent 2 611.Google Scholar
Barnes, I. La Marche, V. C. Jr. and Himmelberg, G., (1967) Geochemical evidence of present day serpentinization Science 156 830–2.10.1126/science.156.3776.830CrossRefGoogle ScholarPubMed
Barnes, I. and O’Neil, J. R., (1969) The relationship between fluids in some fresh alpine-type ultramafics and possible modern serpentinization, Western United States Bull. Geol. Soc. Am. 80 1947–60.10.1130/0016-7606(1969)80[1947:TRBFIS]2.0.CO;2CrossRefGoogle Scholar
Bowen, N. L. and Tuttle, O. F., (1949) The system MgO-SiO2-H2O Bull. Geol. Soc. Am. 60 439–60.CrossRefGoogle Scholar
Bright, J. H., (1959) Report of 1959 exploration program, Condor asbestos properties, Fresno and San Benito Counties, California: Union Carbide Nuclear Company Report .Google Scholar
Brindley, G. W. and Zussman, J., (1959) Infrared absorption data for serpentine minerals Am. Miner. 44 185–8.Google Scholar
Byerly, P. E., (1954) Regional gravity in the central Coast Ranges and the San Joaquin Valley, California .Google Scholar
Cady, W. M. Albee, A. L. and Chidester, A. H., (1963) Bedrock geology and asbestos deposits of Missisquoi Valley and vicinity, Vermont U.S. Geol. Surv. Bull. 1122B 1–78.Google Scholar
Chidester, A. H., (1962) Petrology and geochemistry of selected talc-bearing ultramafic rocks and adjacent country rocks in north-central Vermont U.S. Geol. Surv. Prof. Paper 345 207.Google Scholar
Coleman, R. G., (1957) Mineralogy and petrology of the New Idria District, California .Google Scholar
Coleman, R. G. and Keith, T. E., (1971) A chemical study of serpentinization—Burro Mountain, California J. Petrol. 12 311–28.10.1093/petrology/12.2.311CrossRefGoogle Scholar
Deer, W. A. Howie, R. A. and Zussman, J., (1962) Rock Forming Minerals, Vol. 3, Sheet Silicates 170–90.Google Scholar
Eckel, E. B. and Myers, W. B., (1946) Quicksilver deposits of the New Idria District, San Benito and Fresno Counties, California Calif J. Mines and Geol. 42 2 81–124.Google Scholar
Faust, G. T. and Fahey, J. J., (1962) The serpentine-group minerals U.S. Geol. Sur. Prof. Paper .CrossRefGoogle Scholar
Faust, G. T. and Nagy, B. S., (1967) Solution studies of chrysotile, lizardite, and antigorite U.S. Geol. Surv. Prof. Paper 384-B 93–105.Google Scholar
Grimsicar, A. and Oiepek, V., (1959) Yugoslav serpentine asbestos with special regards to the Stragari asbestos Geol. Razprave in Porocila 5 37–55.Google Scholar
Hostetler, P. B. Coleman, R. G. Mumpton, F. A. and Evans, B., (1966) Bruche in alpine serpentinites Am. Miner. 51 75–98.Google Scholar
Laizure, C. M., (1926) San Benito County: Asbestos: 22nd Rept, State Mineralogist, Calif. 223–4.Google Scholar
Luce, R. W., (1972) Identification of serpentine varieties bv infrared absorption U.S. Geol. Surv. Prof. Paper 750-B 199–201.Google Scholar
Matthews, R. A., (1961) Geology of the Butler Estate chro-mite mine, southwestern Fresno County, California Calif. Div. Mines & Geol. Spec. Rept. 71.Google Scholar
Merritt, P. C., (1962) California asbestos goes to market Mining Engng 14 57–60.Google Scholar
Miller, W. B. (1952) Asbestos in Yugoslavia: Asbestos 34, (2) 2–10; (3) 2–10; (4) 2–6.Google Scholar
1960 Asbestos 42 4.Google Scholar
Mumpton, F. A. Jaffe, H. W. and Thompson, C. S., (1965) Coalingite, a new mineral from the New Idria serpen-tinite, Fresno and San Benito Counties, California Am. Miner. 50 1893–913.Google Scholar
Mumpton, F. A. and Thompson, C. S., (1966) The stability of brucite in the weathering zone of the New Idria ser-pentinite Clays and Clay Minerals, Proc. 14th Nat. Conf. Oxford Pergamon Press 249–57.Google Scholar
Munro, R. C. and Reim, K. M., (1962) Coalinga asbestos fiber, a newcomer to the asbestos industry Can. Mining J. 45–50.Google Scholar
Naumann, A. W. and Dresher, W. H., (1966) The morphology of chrysotile asbestos as inferred from nitrogen adsorption data Am. Miner. 51 711–25.Google Scholar
Page, N. J., (1968) Chemical differences among the serpentine “polymorphs” Am. Miner. 53 201–15.Google Scholar
Page, N. J. and Coleman, R. G., (1968) Serpentine-mineral analyses and physical properties U.S. Geol. Surv. Prof. Paper .Google Scholar
Rice, S. J., (1963) California asbestos industry Calif. Div. Mines & Geol. Inform. Sen. 16 9 1–7.Google Scholar
Turner, F. and Verhoogen, J., (1960) Igneous and Metamorphic Petrology 2nd Edition New York McGraw-Hill.Google Scholar
Wahlstrom, E., (1955) Theoretical igneous Petrology New York Wiley.Google Scholar
Whittaker, E. J. W. and Zussman, J., (1956) The characterization of serpentine minerals Miner. Mag. 31 107–26.Google Scholar
Woolery, R. G., (1966) Asbestos-cellulose blends offer dramatic possibilities Pulp and Paper .Google Scholar
de Wolff, P. D., (1962) The crystal structure of artinite Mg2(OH)2CO3.3H2O Acta Crystall. 5 286–7.Google Scholar
Zussman, J. Brindley, G. W. and Comer, J. J., (1957) Electron diffraction studies of serpentine minerals Am. Miner. 42 133–53.Google Scholar