Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-28T15:17:05.787Z Has data issue: false hasContentIssue false
  • English
  • Français

Coexisting chloritoid and staurolite and the staurolite–chlorite isograd from the Agnew Lake area, Ontario, Canada

Published online by Cambridge University Press:  01 May 2009

J. S. Fox
J. S. Fox
Affiliation:
Department of Mineralogy and Petrology, Cambridge University, Downing Place Cambridge
Get access Rights & Permissions [Opens in a new window]

Summary

Chloritoid and staurolite bearing rocks from the Agnew Lake area in northern Ontario were studied petrographically and with the electron microprobe. A staurolite–chlorite isograd is postulated, above which chloritoid and staurolite coexist in equilibrium, and a Schreinemakers-type petrogenetic grid is constructed to illustrate how the isograd might fit into a paragenetic sequence.

The staurolites from the area are observed to be more ‘siderophile’ than the chloritoids and this suggests that the chlorite participating in the isograd reaction is prograde. This is confirmed in the ‘real’ isograd reaction:

1.559ctd+5.000and+0.009rut+0.058ilm=0.881st+0.039chl+1.366qtz+1.040H2O the coefficients of which are calculated using the mineral analyses of the ideally univariant assemblage staurolite–chloritoid–chlorite–andalusite. Variations in the activity of the unsaturated component ZnO would affect the equilibrium temperature of the reaction and the reaction coefficients.

Type
Articles
Information
Geological Magazine , Volume 108 , Issue 3 , May 1971 , pp. 205 - 219
Copyright
Copyright © Cambridge University Press 1971

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Albee, A. L. 1965. A petrogenetic grid for the Fe–Mg silicates of pelitic schists. Am. J. Sci. 263, 512–36.Google Scholar
Anderson, A. T. 1968. Oxidation of the LeBlanche Lake titaniferous magnetite deposit, Quebec. J. Geol. 76, 528–47.CrossRefGoogle Scholar
Buddington, A. F. & Lindsley, D. H. 1964. Iron–titanium oxide minerals and synthetic equivalents. J. Petrology 5, 310–57.CrossRefGoogle Scholar
Card, K. D. 1964. Metamorphism in the Agnew Lake area, Subdury District, Ontario, Canada. Bull. geol. Soc. Am. 75, 1011–30.CrossRefGoogle Scholar
Card, K. D. 1965. Hyman and Drury Townships. Geol. Rep. Ontario Prov. No. 34.Google Scholar
Carmichael, D. M. 1970. Intersecting isograds in the Whetstone Lake area, Ontario. J. Petrology 11, 147–81.Google Scholar
Deer, W. A., Howie, R. A. & Zussman, J. 1967. An Introduction to the Rock-forming Minerals. Longmans, London, 528 pp.Google Scholar
Eugster, H. P. & Skippen, G. B. 1967. Igneous and metamorphic reactions involving gas equilibria. In Abelson, P. H. (Ed.); Researches in Geochemistry. 2, John Wiley & Sons, New York. Pp. 492–520.Google Scholar
Fairbairn, H. W., Hurley, P. M., Card, K. D. & Knight, C. J. 1969. Correlation of radiometric ages of Nipissing diabase and Huronian metasediments with Proterozoic orogenic events in Ontario. Can. J. Earth Sci. 6, 489–97.Google Scholar
Fisher, G. W. 1966. The effect of variable oxygen activity on isograd reactions in pelitic rocks. Yb. Carnegie Instn Wash. 65, 279–83.Google Scholar
Ganguly, J. 1968. Analysis of the stabilities of chloritoid and staurolite and some equilibria in the system FeO–Al2O3–SiO2–H2O–O2. Am. J. Sci. 266, 277–92.Google Scholar
Guppy, E. M. & Sabine, P. A. 1956. Chemical analyses of igneous rocks, metamorphic rocks and minerals, 1931–1954, compiled from the records of the Geological Survey. Mem. geol. Surv. U.K.Google Scholar
Halferdahl, L. B. 1961. Chloritoid: its composition, x-ray and optical properties, stability and occurrence. J. Petrology 2, 49–135.Google Scholar
Hess, P. C. 1969. The metamorphic paragenesis of cordeirite in pelitic rocks. Contr. Miner. Petrol. 24, 191–207.Google Scholar
Hietanen, A. 1967. On the facies series in various types of metamorphism. J. Geol. 75, 187–215.Google Scholar
Hoschek, G. 1967. Untersuchungen zum stabilitatsbereich von chloritoid und staurolite. Contr. Miner. Petrol. 14, 123–62.Google Scholar
Hoschek, G. 1969. The stability of staurolite and chloritoid and their significance in metamorphism of pelitic rocks. Contr. Miner. Petrol. 22, 208–32.CrossRefGoogle Scholar
Hounslow, A. W. & Moore, J. M., 1967. Chemical petrology of Grenville schists near Fernleigh, Ont. J. Petrology 8, 1–28.Google Scholar
Jackson, E. D., Stevens, R. E. & Bowen, R. W. 1967. A computer based procedure for deriving mineral formulae from mineral analyses. Prof. Pap. U.S. geol. Surv. 575-C, 23–31.Google Scholar
James, H. L. 1955. Zones of regional metamorphism in the Precambrian of northern Michigan. Bull. geol. Soc. Am. 66, 1455–88.Google Scholar
Korzhinskii, D. S. 1959. Physicochemical basis of the analysis of the paragenesis of minerals. Consultants Bureau Inc., New York, 142 pp.Google Scholar
Miyashiro, A. 1968. Evolution of metamorphic belts. J. Petrology 2, 277–311.Google Scholar
Richardson, S. W. 1968. Staurolite stability in a part of the system Fe–Al–Si–O–H. J. Petrology 9, 259–72.Google Scholar
Richardson, S. W., Gilbert, M. C. and Bell, P. M. 1969. Experimental determination of the kyanite-andalusite and andalusite-sillimanite equilibria; the aluminosilicate triple point. Am. J. Sci. 267, 259–72.Google Scholar
Schreinemakers, F. A. H. 1915. Invariant, monovariant and divariant equilibria. Proc. Akad. Wet. Leiden.Google Scholar
Smith, J. V. 1968. The crystal structure of staurolite. Am. Miner. 53, 1139–54.Google Scholar
Thompson, J. B. 1957. The graphical analysis of mineral assemblages in pelitic schists. Am. Miner. 42, 842–58.Google Scholar
Tilley, C. E. 1925. Petrographical notes on some chloritoid rocks. Geol. Mag. 62, 309–18.Google Scholar
Turner, F. J. & Verhoogen, J. 1960. Igneous and metamorphic petrology. McGraw-Hill Book Co. Inc., New York, 694 pp.Google Scholar
Winkler, H. G. F. 1965. Petrogenesis of Metamorphic Rocks. Springer-Verlag, Berlin, 220 pp.CrossRefGoogle Scholar
Zen, E-An. 1966. Construction of pressure-temperature diagrams for multicomponent systems after the method of Schreinemakers. Bull. U.S. geol. Surv. 1225.Google Scholar