Abstract
The low-grade chromite deposits at Fiskenaesset, West Greenland, occur in 0,5–20 m wide horizons in anorthosites which represent the main component of an original layered intrusion, the Fiskenaesset complex. An exposed length of 125 km of this has been mapped, forming conformable stratigraphic horizons in the early Precambrian gneiss basement. The pre-metamorphic chromite deposits have been affected by at least two major phases of folding and metamorphism, but magmatic features are still recognizable. Mineralogical data on the chromite are given together with the petrography of the chromitite. The primary magmatic and secondary metamorphic features of the Fiskenaesset deposits are described and discussed in relation with similar chromite deposits of stratiform type elsewhere in the world.
Zusammenfassung
Im Gebiet von Fiskenaesset, Westgrönland, treten 0,5–20 m mächtige Chromit-Bänder in anorthositischen Gesteinen auf. Die Anorthosite liegen in alt-präkambrischen Gneisen („basement“) und stellen den Hauptanteil des intrusiven Fiskenaesset-Komplexes dar. Dieser Komplex konnte bisher auf eine streichende Länge von 125 km nachgewiesen werden. Er liegt als konforme stratigraphische Einheit in den Gneisen. Der Komplex mit seinen schichtgebundenen Chromit-Vorkommen wurde während mehrerer Deformationsperioden stark beansprucht und dabei hochmetamorph überprägt. Anhand von mineralogischen und petrographischen Untersuchungen werden die primären, magmatischen Merkmale im Verhältnis zu den sekundären, metamorphen Merkmalen der Chromite besprochen. Es werden Vergleiche zu ähnlichen Chromit-Lagerstätten gezogen.
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Bibliography
Cameron, E. N.: Structure and rock sequences of the Critical Zone of the Eastern Bushveld Complex. Mineral. Soc. Am. Spec. Paper 1, 93–107 (1963).
—, Emerson, M. E.: The origin of certain chromite deposits in the eastern part of the Bushveld Complex. Econ. Geol. 54, 1151–1213 (1959).
Ghisler, M.: The chromite deposits at Fiskenaesset. Rapp. Grönlands Geol. Unders. 11, 31–32 (1966).
—, Windley, B. F.: The chromite deposits of the Fiskenaesset region. Rapp. Grönlands Geol. Unders. 12, 39 (1967)
—, Sharma, P. V.: On the applicability of magnetic prospecting for chromite in the Fiskenaesset region, West Greenland. Rapp. Grönlands Geol. Unders. 20, 25 (1969).
Herd, R. K., Windley, B. F., Ghisler, M.: The mode of occurrence and petrogenesis of the sapphirine-bearing and associated rocks of West Greenland. Rapp. Grönlands Geol. Unders. 24, 44 (1969)
Jackson, E. D.: Primary textures and mineral associations in the Ultramafic zone of the Still-water complex, Montana. Prof. Papers U.S. Geol. Survey 358, 106 (1961).
--: Stratigraphic and lateral variation of chromite composition in the Stillwater complex. Spec. Paper Mineral. Soc. Am. 1, 46–54. Editors Fisher, D. J., Frueth, Jr., A. J., Hurlbut, Jr., C. S., Tilley, C. E. Co-ordinating Editor Heinrich, E. W. M. 332 p., 1963.
Klemm, D. D.: Anisotropieeffekte bei kubischen Erzmineralien. Neues Jahrb. Mineral. Abhandl. 97, 337–356 (1962).
Legg, C. A.: Some chromite-ilmenite associations in the Merensky reef, Transvaal. Am. Mineralogist 54, 1347–1354 (1969).
Naidu, P. R. J.: A layered complex in Sittampundi, Madras State, India. Mineral. Soc. Am. Spec. Paper 1, 116–123 (1963).
Ramdohr, P.: Die Erzmineralien und ihre Verwachsungen, 1089 Seiten. Berlin: Akademie-Verlag, 1960.
Sampson, E.: Varieties of chromite deposits. Econ. Geol. 26, 833–39 (1931).
Söhnge, P. C.: The geology of the Messina copper mines and surrounding country. Union S. Afr. Geol. Surv. Mem. 40, 280 (1946).
Subramaniam, A. P.: Mineralogy and petrology of the Sittampundi complex, Salem district, Madras State, India. Bull. Geol. Soc. Am. 67, 317–390 (1956).
Thayer, T. P.: Some critical differences between Alpine-type and stratiform peridotite-gabbro complexes. Int. Geol. Congr. 21st, Norden, pt. 13, 247–59 (1960).
Wager, L. R., Brown, G. M., Wadsworth, W. J.: Types of igneous cumulates. J. Petrol. 1, 73–85 (1960).
Windley, B. F.: Anorthosites and polymetamorphism between Ravns Storö and Sukkertoppen, West Greenland. Rapp. Grönlands Geol. Unders. 11, 27–29 (1966).
—: On the classification of the West Greenland anorthosites. Geol. Rundschau 56, 1020–1026 (1967).
—: New field relations from the early Precambrian of West Greenland. Rapp. Grönlands Geol. Unders. 15, 27–31 (1968).
-- Windley, B. F.: Evolution of the early Precambrian basement complex of southern West Greenland. Geol. Ass. Canada, Spec. Paper 5, 155–61 (1969a).
—: The anorthosites of southern West Greenland. Mem. Am. Ass. Petrol. Geol. 12, 899–915 (1969b).
Zyl, van J. S.: Aspects of the geology of the northern Soutpansberg area. Univ. Stellenbosch Annals 26, sec. A., 1–95 (1950).
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Ghisler, M. Pre-metamorphic folded chromite deposits of stratiform type in the early Precambrian of West Greenland. Mineral. Deposita 5, 223–236 (1970). https://doi.org/10.1007/BF00201989
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DOI: https://doi.org/10.1007/BF00201989