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The tectono-metamorphic evolution of a dismembered ophiolite (Tinos, Cyclades, Greece)

Published online by Cambridge University Press:  01 May 2009

Yaron Katzir
Affiliation:
Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
Alan Matthews
Affiliation:
Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
Zvi Garfunkel
Affiliation:
Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
Manfred Schliestedt
Affiliation:
Institut für Mineralogie, Universität Hannover, Welfengarten 1, D-30167, Hannover, Germany
Dov Avigad
Affiliation:
Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel

Abstract

The six exposures of the Upper tectonic Unit of the Cycladic Massif occurring on the island of Tinos are shown to comprise a metamorphosed dismembered ophiolite complex. The common stratigraphic section consisting of tens-of-metres- thick tectonic slices of mafic phyllites overlain by serpentinites and gabbros is considered to have been derived by a combination of thrusting during obduction and subsequent attenuation by low-angle normal faults. All rock types show evidence of a phase of regional greenschist-facies metamorphism, which in the case of the phyllites is accompanied by penetrative deformation. The greenschist-facies metamorphism in gabbros is preceded by high temperature sea-floor amphibolite-facies alteration, whereas in the serpentinites, the antigorite + forsterite greenschist-facies assemblage overprinted an earlier low temperature lizardite serpentinite. Trace element patterns of the mafic phyllites and a harzburgitic origin of meta-serpentinites suggest a supra subduction zone (SSZ) affinity for the ophiolitic suite. ρ18O values of phyllites, gabbros and serpentinites range from 6 to 15%o. Model calculations indicate that such values are consistent with low temperature (50–200°C) alteration of parent rocks by sea-water at varying water/rock ratios. This would agree with the early low temperature mineralogy of the serpentinites, but the early high temperature alteration of the gabbros would require the presence of 18O-enriched sea-water.The following overall history is suggested for Tinos ophiolitic slices. (1) Oceanic crust was generated at a supra-subduction zone spreading centre with high temperature alteration of gabbros. (2) Tectonic disturbance (its early hot stages recorded in an amphibolitic shear zone at the base of serpentinites) brought the already cooled ultramafics into direct contact with sea-water and caused low-T serpentinization. (3) Tectonism after cooling involved thrusting which caused repetition and inversion of the original order of the oceanic suite. (4) Regional metamorphism of all the ophiolite components at greenschist-facies conditions (−450°C) overprinted the early alteration mineralogy. It was probably induced by continued thrusting and piling up of nappes. The Tinos ophiolite, dated as late Cretaceous and genetically related to other low pressure rock-units of the same age in the Aegean, differs in age and degree of dismemberment and metamorphism from ophiolites in mainland Greece.

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Copyright © Cambridge University Press 1996

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References

Alt, J. C., Muehlenbachs, K., & Honnorez, J., 1986. An oxygen isotopic profile through the upper kilometer of the oceanic crust, DSDP Hole 504B. Earth and Planetary Science Letters 80, 217–29.Google Scholar
Altherr, R., Schliestedt, M., Okrusch, M., Seidel, E., Kreuzer, H., Harre, W., Lenz, H., Wendt, I., & Wagner, G. A., 1979. Geochronology of high pressure rocks on Sifnos (Cyclades, Greece). Contributions to Mineralogy & Petrology 70, 245–55.Google Scholar
Altherr, R., Kreuzer, H., Wendt, I., Lenz, H., Wagner, G. A., Keller, J., Harre, W., & Höhndorf, A., 1982. A Late Oligocene/Early Miocene high temperature belt in the Attic—Cycladic crystalline complex (SE Pelagonian, Greece). Geologisches Jahrbuch E23, 97164.Google Scholar
Altherr, R., Henjes-Kunst, F., Matthews, A., Friedrichsen, H., & Hansen, B. T., 1988. O—Sr isotopic variations in Miocene granitoids from the Aegean: Evidence for an origin by combined assimilation and fractional crystallization. Contributions to Mineralogy & Petrology 100, 528–41.CrossRefGoogle Scholar
Aubouin, J., Bonneau, M., Celet, P., Charvet, J., Clement, B., Degardin, J. M., Dercourt, J., Ferriére, J., Fleury, J. J., Guernet, C., Maillot, H., Mania, J., Mansy, J. L., Terry, J., Thiebault, F., Tsoflias, P., & Verriez, J. J., 1970. Contribution á la géologie des Hellénides: le Gavrovo, le Pinde et la zone ophiolitique Subpélagonienne. Annales de la Société géologique du Nord 90, 277306.Google Scholar
Avigad, D., & Garfunkel, Z., 1989. Low-angle faults above and below a blueschist belt — Tinos Island, Cyclades, Greece. Terra Nova 1, 182–7.Google Scholar
Avigad, D., & Garfunkel, Z., 1991. Uplift and exhumation of high-pressure metamorphic terrains: The example of the Cycladic blueschist belt (Aegean Sea). Tectonophysics 188, 357–72.Google Scholar
Avigad, D., Matthews, A., Evans, B.W., & Garfunkel, Z., 1992. Cooling during the exhumation of a blueschist terrane: Sifnos (Cyclades) Greece., European Journal of Mineralogy 4, 619–34.Google Scholar
Beccaluva, L., Di, Girolamo P., Macciotta, G., & Morra, V., 1983. Magma affinities and fractionation trends in ophio-lites. Ofioliti 8, 307–24.Google Scholar
Bernoulli, D., & Weissert, H., 1985. Sedimentary fabrics in Alpine ophicalcites, South Pennine Arosa zone, Switzerland. Geology 13, 755–8.2.0.CO;2>CrossRefGoogle Scholar
Biju-Duval, B., Dercourt, J., & Le, Pichon X., 1977. From the Tethys ocean to the Mediterranean seas: A plate tectonic model of the evolution of the Western Alpine system. In Structural History of the Mediterranean Basins (eds Biju-Duval, B. and Montadert, L.), pp. 143–64. Paris: Editions Technip.Google Scholar
Bonneau, M., 1984. Correlation of the Hellenide nappes in the south-east Aegean and their tectonic reconstruction. In The Geological Evolution of the Eastern Mediterranean (eds Dixon, J. E. and Robertson, A. H. F.), pp. 517–28. Geological Society of London Special Publication no. 17. London, Oxford: Blackwell Scientific Publications.Google Scholar
Boudier, F., & Coleman, R. G., 1981. Cross section through the peridotite in the Samail ophiolite, southeastern Oman mountains. Journal of Geophysical Research 86B, 2573–92.Google Scholar
Boudier, F., Ceuleneer, G., & Nicolas, A., 1988. Shear zones, thrusts and related magmatism in the Oman ophiolite: Initiation of thrusting on an oceanic ridge. Tectonophysics 151, 275–96.Google Scholar
Boudier, F., & Nicolas, A., 1985. Harzburgite and lherzolite subtypes in ophiolitic and oceanic environments. Earth and Planetary Science Letters 76, 8492.CrossRefGoogle Scholar
Bröcker, M., 1990 a. Blueschist-to-greenschist transition in metabasites from Tinos Island, Cyclades, Greece: Compositional control or fluid infiltration? Lithos 25, 2539.Google Scholar
Bröcker, M., 1990 b. Die metamorphe vulcanosedimentäre abfolge der Insel Tinos (Kykladen, Griechenland) — geologie, petrographie und mineralchemie einer grunschiefer faziell uberpragten hochdruck-/niedrigtemperatur-abfolge. Geotektonische Forschungen 74, 1107.Google Scholar
Bröcker, M., 1991. Geochemistry of metabasic HP/LT rocks and their greenschist facies and contact metamorphic equivalents, Tinos Island (Cyclades, Greece). Chemie der Erde 51, 155–71.Google Scholar
Bröcker, M., Kreuzer, A., Matthews, A., & Okrusch, M., 1993. 40Ar/39 and oxygen isotope studies of poly-metamorphism from Tinos Island, Cycladic blueschist belt, Greece. Journal of Metamorphic Geology 11, 223–40.CrossRefGoogle Scholar
Buick, I. S., 1991. The late Alpine evolution of an extensional shear zone, Naxos, Greece. Journal of the Geological Society, London 148, 93103.CrossRefGoogle Scholar
Burkhard, D. J. M., & O'Neil, J. R., 1988. Contrasting serpentinization processes in the eastern Central Alps. Contributions to Mineralogy & Petrology 99, 498506.Google Scholar
Clayton, R. N., & Mayeda, T. K., 1963. The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotopic analyses. Geochimica et Cosmochimica Acta 53, 725–34.Google Scholar
Dewey, J. F., Pitman, W. C. III, Ryan, W. B. F., & Bonin, J., 1973. Plate tectonics and the evolution of the Alpine system. Bulletin of the Geological Society of America 84, 3137–80.2.0.CO;2>CrossRefGoogle Scholar
Dixon, J. E., & Ridley, J., 1987. Syros. In Chemical Transport in Metasomatic Processes (ed. Helgeson, H. C.), pp. 489501. NATO ASI series. Reidel Publishing Company.Google Scholar
Dürr, S., Altherr, R., Keller, J., Okrusch, M., & Seidel, E., 1978 a. The median Aegean crystalline belt: Stratigraphy, structure, metamorphism, magmatism. In Alps, Appenines, Hellenides (eds Cloos, H., Roeder, D. and Schmidt, K.), pp. 455–77. IUGS Report no. 38. Stuttgart: Schweizerbart.Google Scholar
Dürr, S., Seidel, E., Kreuzer, H., & Harre, W., 1978 b. Témoins d'un métamorphisme d' âge crétacé supérieur dans I' Égéide: datations radiométriques de minéraux provenant de l'île de Nikouriá (Cyclades, Grèce). Bulletin de la Société Géologique de France 2, 209–13.Google Scholar
Evans, B. W., 1977. Metamorphism of Alpine peridotite and serpentinite. Annual Reviews in Earth and Planetary Science 5, 397447.Google Scholar
Gautier, P., & Brun, J. P., 1994. Crustal-scale geometry and kinematics of late-orogenic extension in the central Aegean (Cyclades and Evvia Island). Tectonophysics 238, 399424.CrossRefGoogle Scholar
Girardeau, J., Marcoux, J., & Zao, Yougong, 1984. Lithologic and tectonic environment of the Xigaze ophiolite (Yarlung Zangbo suture zone, Southern Tibet, China) and kinematics of its emplacement. Eclogae Geologicae Helvetiae 77, 153–70.Google Scholar
Gregory, R. T., & Taylor, H. P. Jr, 1981. An oxygen isotope profile in a section of Cretaceous oceanic. crust, Samail ophiolite, Oman: Evidence for 18O buffering of the oceans by deep (>5 km) seawater-hydrothermal circulation at mid-ocean ridges. Journal of Geophysical Research 86B, 2737–55.Google Scholar
Holland, T. J. B., & Powell, R., 1990. An enlarged and updated internally consistent thermodynamic dataset with uncertainties and correlations: the system K2O—Na2O—CaO—MnO—FeO—Fe2O3—Al2O3—TiO2—SiO2—C—H2—O2. Journal ofMetamorphic Geology, 89124.CrossRefGoogle Scholar
Ito, E., & Anderson, A. T Jr, 1983. Submarine metamorphism of gabbros from the Mid-Cayman Rise: Petrographie and mineralogic constraints on hydrothermal processes at slow-spreading ridges. Contributions to Mineralogy & Petrology 82, 371–88.Google Scholar
Jagoutz, E., Palme, H., Baddenhausen, H., Blum, K., Cendales, M., Dreibus, G., Spettel, E., Lorenz, V., & Wänke, H., 1979. The abundances of major, minor and trace elements in the earth's mantle as derived from primitive ultramafic nodules. In Early Solar System and Lunar Regolith (eds Merril, R. B., Bogard, D. D., Hoerz, F., McKay, D. S. and Robertson, P. C.), pp. 2031–50. Proceedings of the 10th Conference on Lunar and Planetary Sciences, Vol.2.Google Scholar
Jones, G., & Robertson, A. H. F., 1991. Tectono-stratigraphy and evolution of the Mesozoic Pindos ophiolite and related units, northwestern Greece. Journal of the Geological Society, London 148, 267–88.CrossRefGoogle Scholar
Kyser, T. K., O'Neil, J. R., & Carmichael, I. S. E., 1982. Genetic relations among basic lavas and ultramafic nodules: Evidence from oxygen isotope compositions. Contributions to Mineralogy & Petrology 81, 88102.Google Scholar
Le, Bas M. J., Le, Maitre R. W., Streckeisen, A., & Zanettin, B. A., 1986. Chemical classification of volcanic rocks based on the total alkali-silica diagram. Journal of Petrology 27, 745–50.Google Scholar
Leake, B. E., 1978. Nomenclature of amphiboles. American Mineralogist 63, 1023–52.Google Scholar
Lee, J., & Lister, G. S., 1992. Late Miocene ductile extension and detachment faulting, Mykonos, Greece. Geology 20, 121–4.Google Scholar
Lister, G. S., Banga, G., & Feenstra, A., 1984. Metamorphic core complexes of Cordilleran type in the Cyclades, Aegean Sea, Greece. Geology 12, 221–5.Google Scholar
Maluski, H., Bonneau, M., & Kienast, J. R., 1987. Dating metamorphic events in the Cycladic area: 39Ar/40Ar data from metamorphic rocks of the island of Syros (Greece). Bulletin de la Société Géologique de France 8, 833–42.CrossRefGoogle Scholar
Mattey, D. P., Marsh, M. G., & Tarney, J., 1980. The geochemistry, mineralogy and petrology of basalts from the West Philippine and Parece Vela basins and from the Palau-Kyushu and West Mariana ridges, Deep Sea Drilling Project Leg 59. In Initial Reports of the Deep Sea Drilling Project 59 (eds Kroenke, L., Scott, R. et al. ), pp. 753800. Washington, D.C.: U.S. Government Printing Office.Google Scholar
Matthews, A., 1994. Oxygen isotope geothermometers for metamorphic rocks. Journal of Metamorphic Geology 12, 211–19.Google Scholar
Matthews, A., & Schliestedt, M., 1984. Evolution of the blueschist and greenschist facies rocks of Sifnos, Cyclades, Greece. Contributions to Mineralogy & Petrology 88, 150–63.Google Scholar
McCrea, J. M., 1950. On the isotopic chemistry of carbonates and a paleotemperature scale. Journal of Chemical Physics 18, 849–57.Google Scholar
Melidonis, N. G., 1980. The geological structure and mineral deposits of Tinos island (Cyclades, Greece). The Geology of Greece 13, 180. Athens: IGME.Google Scholar
Moores, E. J., 1969. Petrology and structure of the Vourinos ophiolitic complex of Northern Greece. Geological Society ofAmerica Special Paper no. 118.Google Scholar
Muehlenbachs, K., 1986. Alteration of the oceanic crust and the 18O history of seawater. In Stable Isotopes in High Temperature Geological Processes (eds Valley, J. W., Taylor, H. P. Jr and O'Neil, J.R), pp. 425–4. Mineralogical Society ofAmerica Reviews in Mineralogy Series, Vol. 16.CrossRefGoogle Scholar
Mullen, E. D., 1983. MnO/TiO2/P2O5: a minor element discriminant for basaltic rocks of oceanic environments and its implications for petrogenesis. Earth and Planetary Science Letters 62, 5362.CrossRefGoogle Scholar
Nicolas, A., 1989. Structures of Ophiolites and Dynamics of Oceanic Lithosphere. Dordrecht: Kluwer Academic Publishers, 367 pp.CrossRefGoogle Scholar
O'Neil, J. R., & Taylor, H. P. Jr, 1967. The oxygen isotope and cation exchange chemistry of feldspars. American Mineralogist 52, 1414–37.Google Scholar
Ottonello, G., Ernst, W. G., & Joron, J. L., 1984. Rare earth and 3d transition element geochemistry of peridotitic rocks: I. Peridotites from the western Alps. Journal of Petrology 25, 343–72.Google Scholar
Papanikolaou, D. J., 1980. Contribution to the geology of the Aegean Sea: The island of Paros. Annales Géologiques des Pays Helléniques 30 /1, 6595.Google Scholar
Papanikolaou, D., 1987. Tectonic evolution of the Cycladic blueschist belt (Aegean Sea, Greece). In Chemical Transport in Metasomatic Processes (ed. Helgeson, H. C.), pp. 429–50. NATO ASI series. Reidel Publishing Company.CrossRefGoogle Scholar
Paterson, M. S., 1978. Experimental Rock Deformation — The Brittle field. Berlin, Heidelberg, New York: Springer-Verlag, 254 pp.Google Scholar
Patzak, M., Okrusch, M., & Kreuzer, H., 1994. The Akrotiri Unit on the island of Tinos, Cyclades, Greece: Witness to a lost terrane of Late Cretaceous age. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen 194, 211–52.CrossRefGoogle Scholar
Pearce, J. A., 1983. Role of sub-continental lithosphere in magma genesis at active continental margins. In Continental Basalts and Mantle Xenoliths (eds Hawkesworth, C. J. and Norry, M. J.), pp. 230–49. Nantwich: Shiva Publishing.Google Scholar
Pearce, J. A., & Cann, J. R., 1973. Tectonic setting of basic volcanic rocks determined using trace element analyses. Earth and Planetary Science Letters 19, 290300.Google Scholar
Pearce, J. A., Lippard, S. J., & Roberts, S., 1984. Characteristics and tectonic significance of supra-subduction zone ophiolites. In Marginal Basin Geology (eds Kokelaar, B. P. and Howells, M. F.), pp. 7794. Geological Society of London Special Publication no. 16. London, Oxford: Blackwell Scientific Publications.Google Scholar
Powell, R., & Holland, T. J. B., 1988. An internally consistent dataset with uncertainties and correlations. 3. Applications to geobarometry worked examples and a computer program. Journal of Metamorphic Geology 6, 173204.Google Scholar
Reinecke, T., Altherr, R., Hartung, B., Hatzipanagiotou, K., Kreuzer, H., Harre, W., Klein, H., Keller, J., Geenen, E., & Böger, H., 1982. Remnants of a Late Cretaceous high temperature belt on the Island of Anafi (Cyclades, Greece). Neues Jahrbuch für Mineralogie Abhandlungen 145, 157–82.Google Scholar
Ridley, J., 1984. Listric normal faulting and reconstruction of the synmetamorphic structural pile of the Cyclades. In The Geological Evolution of the Eastern Mediterranean (eds Dixon, J. E. and Robertson, A. H. F.), pp. 755–62. Geological Society of London Special Publication no. 17. London, Oxford: Blackwell Scientific Publications.Google Scholar
Robertson, A. H. F., Clift, P. D., Degnan, P. J., & Jones, G., 1991. Palaeogeographic and palaeotectonic evolution of the Eastern Mediterranean Neotethys. Palaeogeography, Palaeoclimatology, Palaeoecology 87, 289343.CrossRefGoogle Scholar
Robinson, P., Schumacher, J.C., & Spear, F. S., 1982. Formulation of electron probe analyses. In Amphiboles: Petrology and Experimental Phase Relations (eds Veblen, D. R. and Ribbe, P. H.), pp. 69. American Mineralogical Society Reviews in Mineralogy Series, Vol. 9B.Google Scholar
Saunders, A. D., & Tarney, J., 1979. The geochemistry of basalts from a back-arc spreading centre in the Scotia Sea. Geochimica et Cosmochimica Acta 43, 555–72.CrossRefGoogle Scholar
Saunders, A. D., & Tarney, J., 1984. Geochemical characteristics of basaltic volcanism within back-arc basins. In Marginal Basin Geology (eds Kokelaar, B.P. and Howells, M.F.), pp. 5976. Geological Society of London Special Publication no. 16. London, Oxford: Blackwell Scientific Publications.Google Scholar
Schliestedt, M., 1986. Eclogite-blueschist relationships as evidenced by mineral equilibria in the high-pressure rocks of Sifnos (Cycladic islands), Greece. Journal of Petrology 27, 1437–59.CrossRefGoogle Scholar
Schliestedt, M., Altherr, R., & Matthews, A., 1987. Evolution of the Cycladic crystalline complex: Petrology, isotope geochemistry and geochronology. In Chemical Transport in Metasomatic Processes (ed. Helgeson, H. C.), pp. 389–28. NATO ASI series. Reidel Publishing Company.CrossRefGoogle Scholar
Schliestedt, M., Bartsch, V., Carl, M., Matthews, A., & Henjes-Kunst, F., 1994. The P—T path of greenschistfacies rocks from the island of Kithnos (Cyclades, Greece). Chemie der Erde 54, 281–96.Google Scholar
Schliestedt, M., & Matthews, A., 1987. Transformation of blueschist to greenschist facies rocks as a consequence of fluid infiltration, Sifnos (Cyclades), Greece. Contributions to Mineralogy & Petrology 97, 237–50.Google Scholar
Seck, H. A., Koetz, J., Okrusch, M., Seidel, E., & Stosch, H. G., 1995. Geochemistry of a meta-ophiolite suite: The association of meta-gabbros, eclogites and glaucophanites on the Island of Syros, Greece. European Journal of Mineralogy, in press.Google Scholar
Seidel, E., Okrusch, M., Kreuzer, H., Raschka, H., & Harre, W., 1981. Eo-alpine metamorphism in the uppermost unit of the Cretan nappe system — petrology and geochemistry. Part 2. Synopsis of radiometric dates from high temperature metamorphics and associated ophiolites. Contributions to Mineralogy & Petrology 76, 351–61.Google Scholar
Smith, A. G., 1993. Tectonic significance of the Hellenicm—Dinaric ophiolites. In Magmatic Processes and Plate Tectonics (eds Prichard, H. M., Alabaster, T., Harris, N. B. W. and Neary, C. R.), pp. 213–43. Geological Society of London Special Publication no. 76. London, Oxford: Blackwell Scientific Publications.Google Scholar
Smith, A. G., Hynes, A. J., Menzies, M., Nisbet, E. G., Price, I., Welland, M. J., & Ferriére, J., 1975. The stratigraphy of the Othris mountains, Eastern Central Greece: a deformed Mesozoic continental margin sequence. Eclogae Geologicae Helvetiae 68, 463–81.Google Scholar
Smith, A. G., Woodcock, N. H., & Naylor, M. A., 1979. The structural evolution of a Mesozoic continental margin, Othris mountains, Greece. Journal of the Geological Society, London 136, 589603.Google Scholar
Spear, F. S., 1981. An experimental study of hornblende stability and compositional variability in amphibolite. American Journal of Science 281, 697734.Google Scholar
Stakes, D. S., & O'Neil, J. R., 1982. Mineralogy and stable isotope geochemistry of hydrothermally altered oceanic rocks. Earth and Planetary Science Letters 57, 285304.Google Scholar
Taylor, H. P. Jr, 1968. The oxygen isotope geochemistry of igneous rocks. Contributions to Mineralogy & Petrology 19, 171.CrossRefGoogle Scholar
Taylor, H. P. Jr, 1977. Water/rock interactions and the origin of H2O in granitic batholiths. Journal of the Geological Society, London 133, 509–58.Google Scholar
Trommsdorff, V., & Evans, B. W., 1974. Alpine metamorphism of peridotitic rocks. Schweizerische Mineralogische und Petrographische Mitteilungen 54, 333–52.Google Scholar
Vallance, T. G., 1974. Spilitic degradation of a tholeiitic basalt. Journal of Petrology 15, 7996.CrossRefGoogle Scholar
Vance, J. A., & Dungan, M. A., 1977. Formation of peridotites by deserpentinization in the Darrington and Sultan areas, Cascade Mountains, Washington. Geological Society of America Bulletin, 88, 14971508.Google Scholar
Wachter, E. A., & Hayes, J. M., 1985. Exchange of oxygen isotopes in carbon dioxide— phosphoric acid systems. Chemical Geology 52, 365–74.Google Scholar
Wenner, D. B., & Taylor, H. P. Jr, 1973. Oxygen and hydrogen isotope studies of the serpentinization of ultramafic rocks in oceanic environments and continental ophiolite complexes. American Journal of Science 273, 207–39.CrossRefGoogle Scholar
Whittaker, E. J. W., & Zussman, J., 1956. The characterization of serpentine minerals by X-ray diffraction. Mineralogical Magazine 31, 107–26.Google Scholar
Wicks, F. J., & Whittaker, E. J. W., 1977. Serpentine textures and serpentinization. Canadian Mineralogist 15, 459–88.Google Scholar
Will, T. M., Powell, R., & Holland, T. J. B., 1990. A calculated petrogenic grid for ultramafic rocks in the system Cao—FeO—MgO—Al2O3—SiO2—CO2—H2O at low pressures. Contributions to Mineralogy & Petrology 105, 347–58.Google Scholar
Wood, D. A., Mattey, D. P., Joron, J. L., Marsh, N. G., Tarney, J., & Treuil, M., 1980. A geochemical study of 17 selected samples from basement cores recovered at Sites 447, 448, 449, 450 and 451, Deep Sea Drilling Project Leg 59. In Initial Reports of the Deep Sea Drilling Project 59 (eds Kroenke, L., Scott, R. et al. ), pp. 743–52. Washington, D.C.: U.S. Government Printing Office.Google Scholar