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Petrogenetic implications of mineral crystallization trends of Troodos cumulates, Cyprus

Published online by Cambridge University Press:  01 May 2009

P. Thy
P. Thy
Affiliation:
Department of Geology, University of California, Davis, CA 95616, USA and Geologisk Institut, Aarhus Universitet, DK-8000 Århus C, Denmark
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Abstract

Hole number CY-4 of the Cyprus Crustal Study Project penetrated the lower sheeted dyke complex, gabbros and ultramafic cumulates of the Troodos ophiolite. The lower part of the drill core sampled a coarse-grained plutonic complex revealing phase and cryptic layering and one major magma chamber replenishment. This magma chamber intruded medium-grained gabbroic rocks showing intricate chemical evolution trends reflecting several magma replenishments. In the upper part of the core, the gabbroic cumulates are intruded by fine-grained dykes, which grade into the sheeted dyke complex and chemically can be correlated with the lavas of the lower pillow sequence. The upper pillow lavas are best correlated with the ultramafic cumulates. A study of coexisting plagioclase (An) and mafic mineral (opx Mg #) compositions in the drill core revealed three main rock types: (1) a primitive group (An95–98, Mg #75–85) represented by the lower, coarse-grained gabbroic and ultramafic cumulates. (2) an intermediate group (An86–95 and Mg #70–78) represented by the upper level gabbroic cumulates, and (3) the lower part of the sheeted dyke complex (An60–80 and Mg #60–70). The plagioclase of the gabbros and ultramafic cumulates have an unusually high An content. Numerical simulation of the expected anhydrous, one atmosphere, crystallization trends show that the Troodos trends cannot be reproduced from known spreading or subduction related glasses. Mineralogical evidence indicates that the extrusives and the cumulate sequences of the Troodos ophiolite are genetically related. Glasses from the extrusives, nevertheless, also fail to reproduce the mineral crystallization trends observed in the plutonics. Attempts to model high PH2O crystallization produced trends more consistent with those observed in the cumulates. The very sodium-poor nature of the plagioclase may therefore mainly reflect high PH2O crystallization. High water content is consistent with the inferred subduction zone basin origin for the Troodos ophiolite.

Type
Articles
Information
Geological Magazine , Volume 124 , Issue 1 , January 1987 , pp. 1 - 11
Copyright
Copyright © Cambridge University Press 1987

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References

Arculus, R. J. & Wills, K. J. A. 1980. The petrology of plutonic blocks and inclusions from the Lesser Antilles island arc. Journal of Petrology 21, 743–99.CrossRefGoogle Scholar
Basaltic Volcanism Study Project, 1981. Basaltic Volcanism on the Terrestrial Planets. New York: Pergamon, 1286 pp.Google Scholar
Bender, J. F., Hodges, F. N. & Bence, A. E. 1978. Petrogenesis of basalts from the project FAMOUS area: Experimental study from 0 to 15 kbar. Earth and Planetary Science Letters 41, 277–302.CrossRefGoogle Scholar
Best, M. G. 1963. Petrology of the Guadalupe igneous complex, southwestern Sierra Nevada foothills, California. Journal of Petrology 4, 223–59.CrossRefGoogle Scholar
Browning, P. 1984. Cryptic variation within the cumulate sequence of the Oman ophiolite: Magma chamber depth and petrological implications. In Ophiolites and Oceanic Lithosphere (ed. Gass, I. G., Lippard, S. J. Shelton, A. W.), pp. 71–82. Oxford: Blackwell.Google Scholar
Cameron, W. E. 1985. Petrology and origin of primitive lavas from the Troodos ophiolite, Cyprus. Contributions to Mineralogy and Petrology 89, 239–55.CrossRefGoogle Scholar
Cameron, W. E., McCulloch, M. T. & Walker, D. A. 1983. Boninite petrogenesis: chemical and Nd-Sr isotopic constraints. Earth and Planetary Science Letters 65, 75–89.CrossRefGoogle Scholar
Cameron, W. E. & Nisbet, E. G. 1982. Phanerozoic analogues of komatiitic basalts. In Komatiites (ed. Arndt, N. T., Nisbet, E. G.), pp. 29–50. London: George Allen and Unwin.Google Scholar
Cameron, W. E., Nisbet, E. G. & Dietrich, V. J. 1980. Petrographic dissimilarities between ophiolitic and ocean-floor basalts. In Ophiolites. Proceedings, International Ophiolite Symposium, Cyprus 1979 (ed. Panayiotou, A.), pp. 182–92. Nicosia: Geological Survey Department.Google Scholar
Desmet, A., Gagny, C., Lapierre, H. & Rocci, G. 1980. Organisation spatio-temporelle du complexe filonien du Troodos: Son enracinement dans la chambre magmatique. In Ophiolites. Proceedings, International Ophiolite Symposium, Cyprus 1979 (ed. Panayiotou, A.), pp. 66–72. Nicosia: Geological Survey Department.Google Scholar
Dick, H. J. B. & Bullen, T. 1984. Chromian spinel as a petrogenetic indicator in abyssal and alpine-type peridotites and spatially associated lavas. Contributions to Mineralogy and Petrology 86, 54–76.CrossRefGoogle Scholar
Elthon, D. & Casey, J. F. 1984. Comment on ‘Soret separation of mid-ocean ridge basalt magma’ by D. Walker and S. E. DeLong. Contributions to Mineralogy and Petrology 85, 197–202.CrossRefGoogle Scholar
Elthon, D. & Casey, J. F. 1985. The very depleted nature of certain primary mid-ocean ridge basalts. Geochimica et Cosmochimica Acta 49, 289–98.CrossRefGoogle Scholar
Ewart, A. 1982. The mineralogy and petrology of Tertiary-Recent orogenic volcanic rocks: With special reference to the andesitic-basaltic compositonal range. In Andesites. Orogenic Andesites and Related Rocks (ed. Thorpe, P.), pp. 25–95. Chichester: John Wiley.Google Scholar
Fisk, M. R. 1984. Depths and temperature of midocean-ridge magma chambers and the composition of their source magmas. In Ophiolites and Oceanic Lithosphere (ed. Gass, I. G., Lippard, S. J., Shelton, A. W.). pp. 17–23. Oxford: Blackwell.Google Scholar
Gass, I. G. 1958. Ultrabasic pillow lavas from Cyprus. Geological Magazine 95, 241–51.CrossRefGoogle Scholar
Gass, I. G. 1967. The ultrabasic volcanic assemblage of the Troodos massif, Cyprus. In Ultramafic and Related Rocks (ed. Wyllie, P. J.), pp. 121–34. New York: John Wiley.Google Scholar
Gass, I. G. 1980. The Troodos massif: Its role in the unravelling of the ophiolite problem and its significance in understanding of constructive plate margin processes. In Ophiolites. Proceedings, International Ophiolite Symposium, Cyprus 1979 (ed. Panayiotou, A.), pp. 23–35. Nicosia: Geological Survey Department.Google Scholar
Gill, J. B. 1981. Orogenic Andesites and Plate Tectonics. Berlin: Springer-Verlag, 385 pp.CrossRefGoogle Scholar
Glazner, A. F. 1984. Activities of olivine and plagioclase components in silicate melts and their application to geothermometry. Contributions to Mineralogy and Petrology 88, 260–8.CrossRefGoogle Scholar
Green, T. H. 1969. High-pressure experimental studies on the origin of anorthosite. Canadian Journal of Earth Sciences 6, 427–40.CrossRefGoogle Scholar
Greenbaum, D. 1977. The chromitiferous rocks of the Troodos ophiolite complex, Cyprus. Economic Geology 72. 1175–94.CrossRefGoogle Scholar
Grove, T. L., Gerlach, D. C. & Sando, T. W. 1982. Origin of calc-alkaline series lavas at Medicine Lake Volcano by fractionation, assimilation and mixing. Contributions to Mineralogy and Petrology 80, 160–82.CrossRefGoogle Scholar
Hawkins, J. W. & Melchior, J. T. 1985. Petrology of Mariana trough and Lau basin basalts. Journal of Geophysical Research 90, 11431–68.CrossRefGoogle Scholar
JohanZ., Le Z., Le, Bel, L. & Georgiou, E. 1982. Environment pétrologique des gisements de chromite du complexe ophiolitique du Troodos (Chypre). Bureau de Recherches Géologiques et Minières, Orléans, 65 pp.Google Scholar
Johannes, W. 1978. Melting of plagioclase in the system Ab-An-H2O and Qz-Ab-An-H2O at PH2O = 5 kbars, an equilibrium problem. Contributions to Mineralogy and Petrology 66, 295–303.CrossRefGoogle Scholar
Joplin, G. A. 1971. A Petrography of Australian Igneous Rocks, 3rd ed. Sydney: Angus and Robertson, 235 pp.Google Scholar
Kay, S. M. 1985. Significance of a gabbro xenolith from Ata island. In Geology and Offshore Resources of Pacific Island Arcs – Tonga Region (ed. Scholl, D. W., Vallier, T. L.), pp. 317–21. Houston: Circum-Pacific Council for Energy and Mineral Resources.Google Scholar
Kudo, A. M. & Weill, D. F. 1970. An igneous plagioclase thermometer. Contributions to Mineralogy and Petrology 25, 52–65.CrossRefGoogle Scholar
Longhi, J. 1982. Effects of fractional crystallization and cumulus processes on mineral composition trends of some lunar and terrestrial rock series. Proceedings of the 13th Lunar and Planetary Science Conference, Journal of Geophysical Research 87 (supplement), A54–A64.Google Scholar
McCulloch, M. T. & Cameron, W. E. 1983. Nd-Sr isotopic study of primitive lavas from the Troodos ophiolite, Cyprus: Evidence for a subduction-related setting. Geology 11, 727–31.2.0.CO;2>CrossRefGoogle Scholar
Malpas, J. & Langdon, G. 1984. Petrology of the upper pillow lava suite, Troodos ophiolite, Cyprus. In Ophiolites and Oceanic Lithosphere (ed. Gass, I. G., Lippard, S. J., Shelton, A. W.), pp. 155–67. Oxford: Blackwell.Google Scholar
Melson, W. G., Byerly, G. R., Nelen, J. A., O'Hearn, T., Wright, T. L. & Vallier, T. 1977. A catalog of the major element chemistry of abyssal volcanic glasses. Smithsonian Contributions to the Earth Sciences 19, 31–60.Google Scholar
Menzies, M. & Allen, C. 1974. Plagioclase lherzolite-residual mantle relationships within two eastern Mediterranean ophiolites. Contributions to Mineralogy and Petrology 45, 197–213.CrossRefGoogle Scholar
Miyashiro, A. 1973. The Trodos ophiolite complex was probably formed in an island arc. Earth and Planetary Science Letters 19, 218–24CrossRefGoogle Scholar
Moores, E. M. 1982. Origin and emplacement of ophiolites. Reviews in Geophysics and Space Physics 20, 735–60.CrossRefGoogle Scholar
Moores, E. M. & Thy, P. 1985. Mineral crystallization trends of the Troodos ophiolite: Evidence for the genesis and formation of old oceanic crust. Transactions American Geophysical Union 66, 1123 (abstract).Google Scholar
Moores, E. M. & Vine, F. J. 1971. The Troodos massif, Cyprus and other ophiolites as oceanic crust: Evaluation and implications. Philosophical Transactions of the Royal Society of London A 268, 443–66.Google Scholar
Moores, E. M., Robinson, P. T., Malpas, J. & Xenophontos, C. 1984. The Troodos massif, Cyprus, and other mideast ophiolites. Geology 12, 500–3.2.0.CO;2>CrossRefGoogle Scholar
Natland, J. H. 1981. Petrography and mineral compositions of gabbros recovered in deep sea drilling project hole 453 on the western side of the Mariana trough. Initial Reports, Deep Sea Drilling Project 60, 579–99.Google Scholar
Pearce, J. A. 1980. Geochemical evidence for the genesis and eruptive setting of lavas from Tethyan ophiolites. In Ophiolites. Proceedings, International Ophiolite Symposium, Cyprus 1979 (ed. Panayiotou, A.), pp. 261–72. Nicosia: Geological Survey Department.Google Scholar
Rautenschlein, M., Jenner, G. A., Hertogen, J., Hofmann, A. W., Kerrich, R., Schmincke, H.-U. & White, W. M. 1985. Isotopic and trace element composition of volcanic glasses from the Akaki Canyon, Cyprus: Implications for the origin o the Troodos ophiolite. Earth and Planetary Science Letters 75, 369–83.CrossRefGoogle Scholar
Robinson, P. T., Melson, W. G., O'Hearn, T., & Schmincke, H. U. 1983. Volcanic glass compositions of the Troodos ophiolite, Cyprus. Geology 11, 400–4.2.0.CO;2>CrossRefGoogle Scholar
Schiffman, P., Moores, E., Thy, P., Smith, B. & Varga, R. 1985. Petrologic and hydrothermal evolution of the Solea graben, northern Troodos ophiolite, Cyprus. Transactions American Geophysical Union 66, 1128 (abstract).Google Scholar
Sigurdsson, H. 1981. First-order major element variation in basalt glasses from the Mid-Atlantic ridge: 29° N to 73° N. Journal of Geophysical Research 86, 9483–502.CrossRefGoogle Scholar
Simonian, K. O. & Gass, I. G. 1978. Arakapas fault belt, Cyprus: A fossil transform fault. Geological Society of America Bulletin 89, 1220–30.2.0.CO;2>CrossRefGoogle Scholar
Smewing, J. D., Simonian, K. O. & Gass, I. G. 1975. Metabasalts from the Troodos massif, Cyprus: Genetic implications deduced from petrography and trace element geochemistry. Contributions to Mineralogy and Petrology 51, 49–64.CrossRefGoogle Scholar
Thy, P. 1983. Phase relations in transitional and alkalic basaltic glasses from Iceland. Contributions to Mineralogy and Petrology 82, 232–51.CrossRefGoogle Scholar
Thy, P. 1984. On the nature of the Troodos boninites, Cyprus. Ofioliti 9, 555–68.Google Scholar
Thy, P. & Moores, E. M. 1985. A model for the genesis and evolution of the Troodos lavas, Cyprus. Transactions American Geophysical Union 66, 406 (abstract).Google Scholar
Thy, P., Brooks, C. K. & Walsh, J. N. 1985. Tectonic and petrogenetic implications of major and rare earth element chemistry of Troodos glasses, Cyprus. Lithos 18, 165–78.CrossRefGoogle Scholar
Thy, P., Schiffman, P. & Moores, E. M. 1986. Igneous mineral stratigraphy and chemistry of the Cyprus Crustal Study Project drill core in the plutonic sequences of the Troodos ophiolite. Initial Reports, Cyprus Crustal Study Project, submitted.Google Scholar
Varga, R. J. & Moores, E. M. 1985. Spreading structure of the Troodos ophiolite, Cyprus. Geology 13, 846–50.2.0.CO;2>CrossRefGoogle Scholar
Wager, L. R. & Brown, G. M. 1968. Layered Igneous Rocks. Edinburgh: Oliver and Boyd, 588 pp.Google Scholar
Walker, D., Shibata, T. & DeLong, S. E. 1979. Abyssal tholeiites from the Oceanographer Fracture Zone. II. Phase equilibria and mixing. Contributions to Mineralogy and Petrology 70, 111–25.CrossRefGoogle Scholar
Wilson, J. R, Esbensen, K. H. & Thy, P. 1981. Igneous petrology of the synorogenic Fongen-Hyllingen layered basic complex, south-central Scandinavian Caledonides. Journal of Petrology 22, 584–627.CrossRefGoogle Scholar
Wood, D. A. 1979. Dynamic partial melting: Its application to the petrogeneses of basalts erupted in Iceland, the Faeroe Islands, the Isle of Skye (Scotland) and the Troodos massif (Cyprus). Geochimica et Cosmochimica Acta 43, 1031–46.CrossRefGoogle Scholar
Yoder, H. S. 1969. Calcalkalic andesites: Experimental data bearing the origin of their assumed characteristics. Oregon State Department of Geology and Mineral Industries Bulletin 65, 77–89.Google Scholar