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An oceanic volcano in an island arc setting – Seatura Volcano, Fiji

Published online by Cambridge University Press:  01 May 2009

W. H. Hindle
Affiliation:
Brimfield Hall, Brimfield, Ludlow, Shropshire, U.K.
H. Colley
Affiliation:
Instituut voor Aardwetenschappen, Vrije Universiteit, Postbus 7161, 1007 MC Amsterdam, The Netherlands

Summary

Seatura is a Pliocene caldera-type, shield volcano situated in SW Vanua Levu, Fiji. Shield-building basaltic lavas are predominantly subaerial though there is a shoreline facies of fossiliferous sediment, pillow lava and hyaloclastite. Late-stage events include the intrusion of a dyke swarm in and around the caldera, and deposition of laharic conglomerates. Chemically the rocks are intermediate between tholeiite and alkali basalt and have intraoceanic levels of TiO2. Late-stage derivatives include benmoreite, trachyte, and propylitically altered rocks. The parent magmas are thought to have been partial melts of undepleted mantle at relatively deep levels. Tapping of these deep levels may have been facilitated by extensional plate tectonic conditions existing in the Fiji area during the development of Seatura Volcano.

Type
Articles
Copyright
Copyright © Cambridge University Press 1981

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References

Berggren, W. A. 1973. The Pliocene time scale: calibration of planktonic foraminiferal and calcareous nannoplankton zones. Nature, London. 243 391–7.CrossRefGoogle Scholar
Chayes, F. 1964. A petrographic distinction between Cenozoic volcanics in and around open oceans. J. Geophys. Res. 69 1573–88.CrossRefGoogle Scholar
Coulson, F. I. E. 1971. The geology of Western Vanua Levu. Bull. geol. Surv. Fiji 17.Google Scholar
Ewart, A. 1976. A petrological study of the younger Tongan andesites and dacites and the olivine tholeiites of Niuafo'ou island, S.W. Pacific. Contrib. Mineral. Petrol. 58 121.CrossRefGoogle Scholar
Gill, J. B. 1976(a). From island arc to oceanic islands: Fiji southwestern Pacific. Geology 4 123–6.2.0.CO;2>CrossRefGoogle Scholar
Gill, J. B. 1976(b). Composition and age of Lau basin and ridge rocks: implications for evolution of an interarc basin and remnant arc. Bull. geol. Soc. Amer. 87 1383–95.2.0.CO;2>CrossRefGoogle Scholar
Gill, J. B. & Gorton, M. P. 1973. A proposed geological and geochemical history of eastern Melanesia. In The Western Pacific; Island Arcs, Marginal Seas, and Geochemistry, (ed. Coleman, P. J.), pp. 459–67. Perth: Western Australian University Press.Google Scholar
Guppy, H. B. 1903. Observations of a Naturalist in the Pacific between 1896 and 1899, vol. 1. London: MacMillan.Google Scholar
Hawkins, J. W. 1974. Geology of the Lau basin, a marginal sea behind the Tonga arc. In The Geology of Continental Margins (ed. Burk, C. A. and Drake, C. L.), pp. 505–20. Heidelberg: Springer-Verlag.CrossRefGoogle Scholar
Hedge, C. E., Peterman, Z. E. & Dickinson, W. R. 1972. Petrogenesis of lavas from Western Samoa. Bull. geol. Soc. Amer. 83 2709–14.CrossRefGoogle Scholar
Hindle, W. H. 1976. The geology of west-central Vanua Levu. Bull. Miner. Resour. Div. Fiji 1.Google Scholar
Hughes, G. W. & Turner, C. C. 1977. Upraised Pacific ocean floor, southern Malaita, Solomon Islands. Bull. geol. Soc. Am. 88 412–24.Google Scholar
Kuno, H. 1966. Lateral variation of basalt magma type across continental margins and island arcs. Bull. Volcan. (Ser. 2), 29 195222.CrossRefGoogle Scholar
MacDonald, G. A. & Katsura, T. 1964. Chemical composition of Hawaiian lavas. J. Petrol. 5 82133.Google Scholar
Pearce, J. A. & Gale, G. H. 1977. Identification of ore deposition environment from trace-element geochemistry of associated igneous host rocks. In Volcanic Processes in Ore Genesis (ed. Jones, M. J.), pp. 1424. London: Geological Society.Google Scholar
Reay, A., Rooke, J. M., Wallace, R. C. & Whelan, P. 1974. Lavas from Niuafo'ou island, Tonga, resemble ocean floor basalts. Geology 2 605–6.2.0.CO;2>CrossRefGoogle Scholar
Rickard, M. J. 1966. Reconnaissance geology of Vanua Levu. Mem. geol. Surv. Fiji 2.Google Scholar
Ringwood, A. E. 1975. Composition and Petrology of the Earth's Mantle. New York: McGraw-HillGoogle Scholar
Rodda, P. 1975. Fiji. In The Encyclopedia of World Regional Geology (ed. Fairbridge, R. W.), pp. 278–82. Stroudsberg: Dowden, Hutchinson & Ross.CrossRefGoogle Scholar
Steiger, R. H. & Jäger, E. 1977. Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology. Earth Planet. Sci. Lett. 36 359–62.CrossRefGoogle Scholar
Thornton, C. P. & Tuttle, O. F. 1960. Chemistry of igneous rocks. I. Differentiation index. Am. J. Sci. 258 664–84.CrossRefGoogle Scholar
Yoder, H. S. 1976. Generation of Basaltic Magma. Washington D.C.: National Academy of Sciences.Google Scholar