Abstract
Massive stratiform zinc-lead-copper sulfide ores, in association with cordierite-anthophyllite rocks, occur in adjacent localities of Ambaji and Deri, in Western India. The metasedimentary country rocks, interlayered with amphibolites and intruded by acidic to intermediate plutonic rocks, belong to the Precambrian Delhi Supergroup. The ore minerals identified by detailed mineragraphic studies include: sphalerite, galena, chalcopyrite, pyrite, pyrrhotite (both monclinic and hexagonal phases), magnetite, ilmenite, rutile, arsenopyrite, molybdenite, cubanite, mackinawite, boulangerite, gudmundite, meneghinite, lautite, tenantite, native bismuth, native silver, chalcocite and covellite. The common sulfide-silicate schistosity in the ores, flowage of sulfide streaks and tails around rotated poikiloblasts and in their pressure shadow region developed during early folding (F1) and regional metamorphism of the rocks under green schist facies condition. These were superimposed by a pervasive hornfelsic fabric involving sulfides and silicates and including microfabrics due to annealing and grain growth in sulfides, during a subsequent phase of low pressure thermal metamorphism and related tectonism (F2). Finally certain deformation features and some uncommon fabrics like martensitic lamellae in galena and subgrains in sphalerite developed during a mild deformation episode (F3) in the waning stages of tectonism in the area. Compositional change in the ores during thermal metamorphism was minimal.
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References
Arnold, R. G.: Mixtures of hexagonal and monoclinic pyrrhotite and the measurement of the metal content of pyrrhotite by X-ray diffraction. Am. Mineral. 51, 1221–1227 (1966)
Atkinson, B. K.: Experimental deformation of polycrystalline pyrite: effects of temperature, confining pressure, strain rate and porosity. Econ. Geol. 70, 473–487 (1975)
Barton, P. B., Bethke, P. M., Toulmin, P. III.: Equilibrium in ore deposits. Miner. Soc. Am. Sp. paper. 1, 171–185 (1963)
Clark, B. R., Kelley, W. C.: Sulfide deformation studies: I Experimental deformation of pyrrhotite and sphalerite to 2000 bars and 500°C. Econ. Geol. 68, 332–352 (1973)
Coulson, A. L.: The geology of the Sirohi state, Rajputana. Mem. Geol. Surv. India. 63, pt. 1, p. 166 (1933)
Deb, M.: Some observations on the mineralogy and metamorphism of the Zn-Pb-Cu ores from Deri-Ambaji area, Banaskantha district, Gujarat. J. Geol. Soc. India. 14, 419–423 (1973)
- Geological setting of the Deri-Ambaji base metal deposits in the Precambrian of Western India. International seminar on tectonics and metallogeny of S. E. Asia and far east. Abstr. 85–86, Misc. Publ. Geol. Surv. India, 34 (1974)
- Genesis and metamorphic evolution of two stratiform massive sulfide deposits at Ambaji-Deri, in the Precambrians of Western India. Communicated to Econ. Geol. (1978)
G. S. I.: Information pamphlet of Geological Survey of India, western region, Gujarat Circle, p. 17 (1972)
Gill, J. E.: Experimental deformation and annealing of sulfides and interpretation of ore texture. Econ. Geol. 64, 500–508 (1969)
Graf, J. L. (Jr.), Skinner, B. J.: Strength and deformation of pyrite and pyrrhotite. Econ. Geol. 65, 206–215 (1970)
Heron, A. M., Ghosh, P. K.: The geology of Palanpur, Danta and parts of Idar States. Rec. Geol. Surv. India. 72, pt. 4, 367–412 (1938)
James, R. S., Grieve, R. A. F., Pauk, L.: The petrology of cordierite-anthophyllite gneisses and associated mafic and pelitic gneisses at Manitouwadge, On tario. Am. J. Sci. 278, 41–63 (1978)
McDonald, J. A.: Metamorphism and its effects on sulfide assemblages. Miner. Deposita, 2, 200–220 (1967)
Mookherjee, A.: Ores and metamorphism: Temporal and genetic relationships. in Handbook of stratabound and stratiform ore deposits, Ed. K. H. Wolf, Elsevier Sci. Publ. Co., Amsterdam. 4, 203–260 (1976)
Ramdohr, P.: Ore minerals and their intergrowths. English Translation of 3rd Ed. Pergamon, Oxford, p. 1174 (1969)
Ramsay, C. R., Davidson, L. R.: Cordierite anthophyllite rocks formed by isochemical regional metamorphism at Mary Kathleen, north western Queensland, Australia. Proc. Roy. Soc. Queensland. 85, no. 4, 43–55 (1974)
Reed-Hill, R. E.: Physical metallurgy principles. Litton Educational Publishing Inc., New York, 2nd Edition, p. 920 (1966)
Sarkar, S. C.: Sulfide mineralization at Sargipalli, Orissa, India. Econ. Geol. 69, 206–217 (1974)
Sarkar, S. C., Deb, M.: Metamorphism of sulfides of the Singhbhum Copper belt, India — the evidence from the ore fabric. Econ. Geol. 69, 1282–1293 (1974)
Scott, S. D., Barnes, H. L.: Sphalerite geothermometry and geobarometry Econ. Geol. 66, 653–669 (1971)
- Experimental methods in sulfide synthesis. In: Miner. Soc. Am. Short Course notes, 1, ‘sulfide mineralogy’, S1–S38 (1974)
Scott, S. D., Both, R. A., Kissin, S. A.: Sulfide petrology of the Broken Hill region, New South Wales, Econ. Geol. 72, 1410–1425 (1977)
Shewmon, P. G.: Transformations in metals. McGraw Hill Book Co., Inc., New York, p. 394 (1969)
Smith, C. S.: Some elementary principles of polycrystalline microstructure. Metall. Rev. 9, 1–48 (1964)
Stanton, R. L., Gorman, H.: A phenomenological study of grain boundary migration in some common sulfides. Econ. Geol. 63, 907–923 (1968)
Stanton, R. L., Willey, H. G.: Experiments on a specimen of galena ore from Coeur d'Alene, Idaho. Econ. Geol. 67, 776–788 (1972)
Stanton, R. L.: Ore petrology, McGraw-Hill Book Co., New York, p. 713 (1972)
Uytenbogaardt, W., Burke, E. A. J.: Tables for microscopic identification of ore minerals. Elsevier, Amsterdam, p. 430 (1971)
Vokes, F. M.: A review of the metamorphism of sulfide deposits. Earth-Sci. Rev., 5, 99–143 (1969)
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Deb, M. Polymetamorphism of ores in Precambrian stratiform massive sulfide deposits at Ambaji-Deri, Western India. Mineral. Deposita 14, 21–31 (1979). https://doi.org/10.1007/BF00201865
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DOI: https://doi.org/10.1007/BF00201865