Skip to main content
Log in

Contact metamorphosed dunite-harzburgite complex in the Chugoku district, western Japan

  • Published:
Contributions to Mineralogy and Petrology Aims and scope Submit manuscript

Abstract

The Tari-Misaka ultramafic complex, which is emplaced into the Paleozoic sediments and thermally metamorphosed by two younger granitic masses, is divided into four zones on the basis of the mineral assemblage. They are, in order of increasing metamorphic grade: Zone I antigorite-olivine-orthopyroxene-clinopyroxene. Zone II olivine-talc. Zone III olivine-anthophyllite. Zone IV olivine-orthopyroxene.

Strongly serpentinized clinopyroxene-bearing harzburgite in Zone I is similar to ordinary Alpine-type harzburgite. In Zonne II, two kinds of olivine are recognized. One is Mg-rich olivine (Fo93 to Fo97) with opaque inclusions and is probably a recrystallization product of serpentine with talc. The other is Fe-rich olivine (Fo88 to Fo93) free of opaque inclusions and is probably a relic of the primary peridotite. Olivine in Zone III and Zone IV is also relatively Mg-rich (Fo91 to Fo95).

Chromitite in Zone IV commonly has an assemblage, olivine+cordierite+Mg-Al spinel (Mg/Mg+Fe2+, more than 0.9). Enstatite is rare and coexists with less magnesian Mg-Al spinel (Mg/Mg+Fe2+, less than 0.9).

Petrological and mineralogical characters of the ultramafic rocks can be well explained by thermal metamorphism of strongly serpentinized peridotite by granitic intrusion. Metamorphic zones are consistent with the experimental results in the system MgO-SiO2-H2O. The assemblage olivine+cordierite indicates that the metamorphism occurred at relatively low pressures (<3kb).

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Arai, S.: Compositional variation of olivine in rooks of the Tari-Misaka ultramafic complex and its interpretation. Proc. Japan Acad. 49, 649–653 (1973)

    Google Scholar 

  • Arai, S.: “Non-calciferous” orthopyroxene and its bearing on the petrogenesis of ultramafic rocks in Sangun and Joetsu zones. J. Japan. Assoc. Mineral. Petrol. Econ. Geol. 69, 343–353 (1974)

    Google Scholar 

  • Evans, B. W., Trommsdorff, V.: Stability of enstatite + talc, and CO2-metasomatism of metaperidodite, Val d'Efra, Lepontine Alps. Am. J. Sci. 274, 274–296 (1974)

    Google Scholar 

  • Fawcett, J. J., Yoder, H. S., Jr.: Phase relationships of chlorites in the system MgO-Al2O3-SiO2-H2O. Am. Mineralogist 51, 353–380 (1966)

    Google Scholar 

  • Greenwood, H. J.: The synthesis and stability of anthophyllite. J. Petrol. 4, 315–351 (1963)

    Google Scholar 

  • Hey, M. H.: A new review of the chlorites. Mineral. Mag. 30, 277–292 (1954)

    Google Scholar 

  • Himmelberg, G. R., Coleman, R. G.: Chemistry of primary minerals and rocks from the Red Mountain—Del Puerto ultramafic mass, California. U. S. Geol. Surv. Profess. Papers 600-C, 18–26 (1968)

    Google Scholar 

  • Loney, R. A., Himmelberg, G. R., Coleman, R. G.: Structure and petrology of the Alpine-type peridodite at Burro Mountain, California. U.S.A. J. Petrol. 12, 245–309 (1971)

    Google Scholar 

  • Nakamura, Y., Kushiro, I.: Compositional relations of coexisting orthopyroxene, pigeonite and augite in a tholeiitic andesite from Hakone volcano. Contrib. Mineral. Petrol. 26, 265–275 (1970)

    Google Scholar 

  • Research Group of Peridotite Intrusion: Ultramafic rooks in Japan. J. Geol. Soc. Japan 73, 543–553 (1967)

    Google Scholar 

  • Rice, J. M., Evans, B. W., Trommsdorff, V.: Widespread occurrence of magnesiocummingtonite in ultramafic schists, Cima di Gagnone, Ticino, Switzerland. Contrib. Mineral. Petrol. 43, 245–251 (1974)

    Google Scholar 

  • Seifert, P.: Stability of sapphirine: A study of the aluminous part of the system MgO-Al2-O3-SiO2-H2O. J. Geol. 82, 173–204 (1974)

    Google Scholar 

  • Springer, R. K.: Contact metamorphosed ultramafic rocks in the western Sierra Nevada foot-hills, California. J. Petrol. 15, 160–196 (1974)

    Google Scholar 

  • Trommsdorff, V., Evans, B. W.: Progressive metamorphism of antigorite schists in the Bergell tonalite aureole (Italy). Am. J. Sci. 272, 423–437 (1972)

    Google Scholar 

  • Trommsdorff, V. and Evans, B. W.: Alpine metamorphism of peridotitic rocks. Schweiz. Mineral. Petrogr. Mitt. 54, 333–352 (1974)

    Google Scholar 

  • Wood, B. J., Banno, S.: Garnet-orthopyroxene and orthopyroxene-clinopyroxene relationships in simple and complex systems. Contrib. Mineral. Petrol. 42, 109–124 (1973)

    Google Scholar 

  • Yoder, H. S., Jr.: Spilites and serpentinites. Yearbook Carnegie Inst. Wash. 65, 269–279 (1967)

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Arai, S. Contact metamorphosed dunite-harzburgite complex in the Chugoku district, western Japan. Contr. Mineral. and Petrol. 52, 1–16 (1975). https://doi.org/10.1007/BF00377998

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00377998

Keywords

Navigation