Abstract
Chemial analyses of twelve amphiboles from the area around Terakanambi are presented. Results indicate that they are ferro-hornblende and ferro-pargasitic hornblende types in banded iron formations; magnesio hornblende in ultramafic rocks and edenite; and ferroan pargasite and ferroan pargasitic hornblende types in calcamphibolites. Titanium content in the amphiboles of the present study is relatively low compared to results from similar zones elsewhere. The lower titanium content of the amphiboles may be attributed to either bulk chemical composition or to low oxygen fugacity. Mg/Fe ratios vary considerably and it is mainly controlled by host rock composition. The plots of calcic amphiboles on (lOONa/Ca + Na)/(100 Al/Si + Al) and Aliv/Alvi diagrams indicate that they are of medium to low pressure type.
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References
Anantha Iyer G V and Narayanan Kutty T R 1976 Geochemistry of amphiboles from the Precambrian of Karnataka;J. Geol. Soc. India 17 17–36
Boyle A P 1986 Metamorphism of basic and pelitic rocks at Sulitjelma, Norway;Lithos 19 113–128
Brown E H 1977 The crossite content of Ca amphibole as a guide to pressure of metamorphism;J. Petrol. 18 53–72
Coolen J J M 1980 Chemical petrology of the Furua granulite complex, southern Tanzania;GUA pap. Geol. 1 13 1246
Cooper A F and Lovering J F 1970 Greenschist amphiboles from Haast river, New Zealand;Contrib. Mineral. Petrol. 27 11–24.
Evans B W 1977 Metamorphism of Alpine peridotite and serpentinite;Annu. Rev. Earth Planet. Sci. 5 397–447
Grapes R H and Graham C M 1978 The actinolitehornblende series in metabasites and the so-called miscibility gap: A review;Lithos 11 85–97
Grapes R H, Hashimoto S and Miyashita S C 1977 Amphiboles of a metagabbro amphibolite sequence, Hidaka metamorphic belt, Hokkaido;J. Petrol. 18 285–318
Hall R 1985 Mg-Fe-Mn distribution in amphiboles, pyroxenes and garnets and implications for conditions of metamorphism of high grade early Archaean iron formation, Southernwest Greenland;Mineral. Mag. 49 117–128
Helz R T 1973 Phase relations of the basalts in their melting range at pH20–5 kbar as a function of oxygen fugacity. Part I. Mafic phases;J. Petrol. 14 249–306.
Hormann P K, Raith M, Raase P, Ackermand D and Seifert F 1980 The granulite complex of Finnish Lapland: Petrology and metamorphic conditions in the Ivalojoki-Inarijarvi area;Geol. Surv. Finland Bull. 308 1–55
Janardhan A S, Shadakshara Swamy N and Capdevila R 1986 Banded iron formation and associated manganiferous horizons of the Sargur supracrustals, southern Karnataka;J. Geol. Soc. India 28 179–188
Kamineni D C 1986 A petrochemical study of calcic amphiboles from the East Bull lake anorthositegabbro layered complex, District of Algoma, Ontario;Contrib. Mineral. Petrol. 93 471–481
Klein C 1969 Two amphibole assemblages in the system actinolite-hornblende-glaucophane;Am. Mineral. 54 212–237
Klein C 1983 Diagenesis and metamorphism of Precambrian banded iron formation inIron formations; Facts and problems (eds) A F Trendall and R C Morris, (Amsterdam; Elsevier) 417–469
Krishnanath R 1981 Coexisting humite-chondrodite-spinel-magnesium calcite assemblages from the calc-silicate rocks of Ambasamudram, Tamil Nadu, India;J. Geol. Soc. India 22 235–242
Laird J and Albee A L 1981 Pressure, temperature and the time indicators in mafic schists; their application to reconstructing the polymetamorphic history of Vermount;Am. J. Sci. 281 127–175
Leake B E 1965 The relationship between tetrahedral aluminium and the maximum possible octahedral aluminium in natural calciferous and subcalciferous amphiboles;Am. Mineral. 50 843–851
Leake B E 1968 A catalogue of analysed calciferous and subcalciferous amphiboles together with their nomenclature and associated minerals;Geol. Soc. Am. Spec, paper 68 1–210
Leake B E 1971 On aluminous and edenitic hornblendes;Mineral. Mag. 38 389–407
Leake B E 1978 Nomenclature of amphiboles;Am. Mineral. 63 1023–1053
Mahabaleswar B and Vasant Kumar I R 1983 Mineral chemistry of hornblendes from the charnockites of Karnataka, India;Acta Miner. Petrol. 26 115–123
Mahabaleswar B, Ananthamurthy K S and Basavanna M 1984 Pressure-temperature estimates of the iron formations of Sivasamudram area, Karnataka;J. Geol. Soc. India 25 564–569
Raase P 1974 Al and Ti contents of hornblende, indicators of pressure and temperature of regional metamorphism;Contrib. Mineral. Petrol. 45 179–203
Raase P, Raith M, Ackermand D and Lai R K 1986 Progressive metamorphism of mafic rocks from greenschist to granulite facies in the Dharwar craton of South India;J. Geol. 94 261–282
Rice J M 1977 Progressive metamorphism of impure dolomitic limestone in the Marysville aureole, Montana;Am. J. Sci. 277 1–24
Shadakshara Swamy N 1983 Petrology and structure of the metasediments and the associated gneisses around Terakanambi, southern Karnataka; Unpublished PhD thesis, University of Mysore
Sharma R S 1982 Petrology of a scapolite bearing rock from Karera, District Bhilwara, Rajasthan;J. Geol. Soc. India 23 319–329
Sivaprakash C 1981 Petrology of calc-silicate rocks from Koduru, Andhra Pradesh, India;Contrib. Mineral. Petrol. 77 121–128
Spear F S 1981 An experimental study of hornblende stability and compositional variability in amphibolite;Am. J. Sci. 281 697–734
Srikantappa C, Raith M and Ackermand D 1985 High grade regional metamorphism of ultramafic and mafic rocks from the Archaean Sargur terrane, Karnataka, South India;Precambrian Res. 30 189–219
Yurkova R M, Peyve A A, Zinkevich V P and Cherkashin V I 1985 Amphibolites of the Shirshov ridge, Bering Sea;Int. Geol. Rev. 27 1051–1068
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Shadakshara Swamy, N., Mahabaleswar, B. Chemistry of calcic amphiboles from the area around Terakanambi, southern Karnataka. Proc. Indian Acad. Sci. (Earth Planet Sci.) 97, 1–10 (1988). https://doi.org/10.1007/BF02861622
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DOI: https://doi.org/10.1007/BF02861622