Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-24T01:32:48.777Z Has data issue: false hasContentIssue false

The Formation of Sulfides During Alteration of Biotite to Chlorite-Corrensite

Published online by Cambridge University Press:  28 February 2024

Gejing Li*
Affiliation:
Department of Geological Sciences, The University of Michigan, Ann Arbor, Michigan 48109-1063
Donald R. Peacor
Affiliation:
Department of Geological Sciences, The University of Michigan, Ann Arbor, Michigan 48109-1063
Eric J. Essene
Affiliation:
Department of Geological Sciences, The University of Michigan, Ann Arbor, Michigan 48109-1063
*
Present address: Department of Geology, Arizona State University, P.O. Box 871404, Tempe, Arizona 85287-1404.
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Transmission electron microscopy/analytical electron microscopy (TEM/AEM) were utilized to study pyrite and sphalerite inclusions in chlorite or mixed-layer chlorite-corrensite from an analcimized ash bed in the Etalian stage (Middle Triassic), South Otago, New Zealand. These sulfide inclusions occur as elongated crystals up to 1 × 15 µm in size, within lens-shaped voids between separated, deformed (001) layers of (primarily) chlorite and mixed-layer chlorite-corrensite grains of typical detrital shape or chlorite packets in chlorite-mica stacks (intergrowths of chlorite and phengite packets) up to 40 × 150 µm in size. Relict biotite layers within chlorite, mixed-layer chlorite-corrensite and berthierine have textures implying replacement of the former by the latter, whereas in other unaltered samples only fresh biotite was observed. Anatase occurs in otherwise Ti-free chlorite, whereas relict biotite contains significant Ti (0.3 moles per 22 oxygen atoms). No sulfide minerals have been found in fresh biotite and phengite.

Mass balance considerations indicate that S and Zn were introduced via pore fluids and that the Fe was provided by the decomposition of biotite to secondary phyllosilicates. The alteration of biotite and the reaction of biotite to form chlorite and pyrite is controlled by aH+/aK+ as well as oxidation of reduced S species or reduction of oxidized S species from solution. Simple calculations with the observed compositions of chlorite and biotite suggest that some of the Fe in biotite was actually removed in solution rather than precipitated in pyrite and chlorite. Similar textures are abundant in ferroan phyllosilicates elsewhere, implying that the mechanism may apply widely to precipitation of sulfides in phyllosilicates during early diagenesis of sediments.

Type
Research Article
Copyright
Copyright © 1998, The Clay Minerals Society

Footnotes

Contribution Number 507 from the Mineralogical Laboratory, Department of Geological Sciences, The University of Michigan.

References

Ahn, J.H. and Peacor, D.R., 1987 Kaolinitization of biotite: TEM data and implications for an alteration mechanism Am Mineral 72 353356.Google Scholar
Ahn, J.H. Peacor, D.R. and Coombs, D.S., 1988 Formation mechanisms of illite, chlorite and mixed layer illite-chlorite in Triassic volcanogenic sediments from the Southland Syn-cline, New Zealand Contrib Mineral Petrol 99 8289 10.1007/BF00399368.CrossRefGoogle Scholar
Ahn, J.H. Xu, H. and Buseck, P.R., 1997 Transmission electron microscopy of native copper inclusions in illite Clays Clay Miner 45 295297 10.1346/CCMN.1997.0450218.CrossRefGoogle Scholar
Boles, J.R., 1971 Synthesis of analcime from natural heuland-ite and clinoptilolite Am Mineral 56 17241734.Google Scholar
Boles, J.R. and Coombs, D.S., 1975 Mineral reactions in zeolitic Triassic tuff, Hokonui Hills, New Zealand Geol Soc Am Bull 86 163173 10.1130/0016-7606(1975)86<163:MRIZTT>2.0.CO;2.2.0.CO;2>CrossRefGoogle Scholar
Canfield, D.E. Raiswell, R. and Bottrell, S., 1992 The reactivity of sedimentary iron minerals toward sulfide Am J Sci 292 659683 10.2475/ajs.292.9.659.CrossRefGoogle Scholar
Coombs, D.S., 1965 Sedimentary analcime rocks and sodium-rich gneisses Mineral Mag 34 144158.Google Scholar
Coombs, D.S. and Cox, S., 1991 Low and very low-grade meta-morphism in southern New Zealand Geol Soc New Zealand Mise Publ 58.Google Scholar
Coombs, D.S. Ellis, A.J. Fyfe, W.S. and Taylor, A.M., 1959 The zeolite facies, with comments on the interpretation of hydro-thermal syntheses Geochim Cosmochim Acta 17 53107 10.1016/0016-7037(59)90079-1.CrossRefGoogle Scholar
Guthrie, G.D. and Veblen, D.R., 1990 Interpreting one-dimentional high-resolution transmission electron micrographs of sheet silicate by computer simulation Am Mineral 75 276288.Google Scholar
Helgeson, H.C., Delaney, J.M., Nesbitt, H.W. and Bird, D.K.. 1978. Summary and critique of the thermodynamic properties of rock-forming minerals. Am J Sci 278A. 229 p.Google Scholar
Hover, V.C. Peacor, D.R. and Walter, L.M., 1996 STEM/AEM evidence for preservation of diagenetic fabrics in Devonian shales: Implications for fluid/rock interaction in cratonic basins J Sed Res 66 519530.Google Scholar
Ilton, E.S. Earley, D. III Morazas, D. and Veblen, D.R., 1992 Reaction of some trioctahedral micas with copper sulfate solutions at 25 °C and 1 atmosphere: An electron microscope and transmission electron microscopy investigation Econ Geol 87 18131829 10.2113/gsecongeo.87.7.1813.CrossRefGoogle Scholar
Ilton, E.S. and Veblen, D.R., 1988 Copper inclusions in sheet silicate from porphyry Cu deposits Nature 334 516518 10.1038/334516a0.CrossRefGoogle Scholar
Ilton, E.S. and Veblen, D.R., 1993 Origin and mode of copper enrichment in biotite from rocks associated with porphyry copper deposits: A TEM investigation Econ Geol 88 885900 10.2113/gsecongeo.88.4.885.CrossRefGoogle Scholar
Jiang, W.-T. and Peacor, D.R., 1994 Formation of corrensite, chlorite and chlorite-mica stacks by replacement of detrital biotite in very-low grade pelitic rocks J Metam Geol 12 867884 10.1111/j.1525-1314.1994.tb00065.x.CrossRefGoogle Scholar
Jiang, W.-T. and Peacor, D.R., 1994 Prograde transitions of corrensite and chlorite in low-grade pelitic rocks from the Gaspé Peninsula, Quebec Clays Clay Miner 42 497517 10.1346/CCMN.1994.0420501.CrossRefGoogle Scholar
Li, G., 1996 Evolution of phyllosilicates through diagenesis and low-grade metamorphism in a prograde sequence of pelitic rocks from Southern New Zealand [Ph.D. thesis], Univ Michigan .Google Scholar
Li, G. Mauk, J.L. and Peacor, D.R., 1995 Preservation of clay minerals in the Precambrian (1.1 Ga) Nonesuch Formation in the vicinity of the White Pine Copper Mine, Michigan Clays Clay Miner 43 361376 10.1346/CCMN.1995.0430311.CrossRefGoogle Scholar
Li, G. Peacor, D.R. Merriman, R.J. Roberts, B. and van der Pluijm, B.A., 1994 TEM and AEM constraints on the origin and significance of chlorite-mica stacks in slates: An example from central Wales, U.K J Struct Geol 16 11391157 10.1016/0191-8141(94)90058-2.CrossRefGoogle Scholar
Shau, Y.-H. Peacor, D.R. and Essene, E.J., 1990 Corrensite and mixed-layer chlorite/corrensite in metabasalt from northern Taiwan: TEM/AEM, EMPA, XRD, and optical studies Contrib Mineral Petrol 105 123142 10.1007/BF00678980.CrossRefGoogle Scholar