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Petrology of seamounts northwest of Samoa and their relation to Samoan volcanism

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Petrological and geochemical data on dredged samples from five submarine volcanos northwest of Samoa indicate that three of these volcanos belong to the Samoan volcanic province (Field, Lalla Rookh, and Combe banks), and two belong to separate magmatic zones (Wallis Islands and Alexa Bank). The Samoan volcanic province increases in age westward and both shield-building tholeiitic and alkalic lavas (Combe Bank) and strongly undersaturated (post-erosional?) melilitites or nephelinites and ankaramites (Field and Lalla Rookh banks) are present. The age progression and petrochemical character of these rocks is consistent with a fixed hotspot beneath eastern Samoa. Slightly askew from this trend is Alexa Bank where dredged lavas are ocean-island tholeiites; however, its radiometric age and compositional characteristics apparently preclude its association with Samoa by a fixed-hotspot model. Dredged volcanic rocks from near the Wallis Islands are geochemically, petrologically, and temporally different from Samoan volcanism, but are similar in these respects to Quaternary volcanism in Rotuma and Fiji and may be related to plate reorganization accompanying opening of the North Fiji Basin.

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  1. Briqueu L, Bougault H, and Joron JL (1984) Quantification of Nb, Ta, Ti, and V anomalies in magmas associated with subduction zones: petrogenetic implications. Earth Planet Sci Lett 68: 297–308

  2. Brocher TM (1986) On the age progression of the seamounts west of the Samoan Islands, SW Pacific. In: Brocher TM (ed) Investigations of the Northern Melanesian Borderland, AAPG Circum-Pacific Earth Sci Series, pp 172–185

  3. Chaproniere GCH (1986) Late Tertiary and Quaternary foraminiferal biostratigraphy and paleobathymetry of cores and dredge samples from cruise KK820316 Leg 2. In: Brocher TM (ed) Investigations of the Northern Melanesian Borderland, AAPG Circum-Pacific Earth Sci Series, pp 102–121

  4. Chase CG (1971) Tectonic history of the Fiji Plateau. Bull Geol Soc Am 82: 3087–3110

  5. Duncan R (1986) Radiometric ages from volcanic rocks along the New Hebrides-Samoa Lineament. In: Brocher TM (ed) Investigations of the Northern Melanesian Borderland, AAPG Circum-Pacific Earth Sci Series, pp 65–74

  6. Fodor RV, Keil K, Bunch TE (1975) Contributions to the mineral chemistry of Hawaiian rocks, IV. Pyroxenes in rocks from Haleakala and West Maui volcanoes, Maui, Hawaii. Contrib Mineral Petrol 50: 173–195

  7. Giardini D, Woodhouse JH (1986) Horizontal shear flow in the mantle beneath the Tonga arc. Nature 319: 551–555

  8. Gill JB (1976) From island arc to oceanic islands: Fiji, southwestern Pacific. Geology 4: 123–126

  9. Gill JB, Stork AL, Whelan PM (1984) Volcanism accompanying back-arc basin development in the southwest Pacific. Tectonophysics 102: 207–224

  10. Hawkins JW, Natland JH (1975) Nephelinites and basanites of the Samoan linear volcanic chain: their possible tectonic significance. Earth Planet Sci Lett 24: 427–439

  11. Hindle WH (1970) The geochemistry of volcanism from Vanua Levu and other islands of the Fiji group and their petrogenetic significance. MSc Thesis, University of Leeds

  12. Hindle WH, Colley H (1981) An oceanic volcano in an island arc setting- Seatura Volcano, Fiji. Geol Mag 118: 1–14

  13. Jezek PA, Bryan WB, Haggerty SE, Johnson HP (1977) Petrography, petrology, and tectonic implications of Mitre Island, Northern Fiji Plateau. Mar Geol 24: 123–148

  14. Johnson KTM (1983) The petrology and tectonic evolution of seamounts and banks of the Northern Melanesian Borderland, southwest Pacific. MS Thesis, University of Hawaii, p 116

  15. Johnson T, Molnar P (1972) Focal mechanisms and plate tectonics of the southwest Pacific. J Geophys Res 77: 5000–5032

  16. Leeman WP, Budahn JR, Gerlach DC, Smith DR, Powell BN (1980) Origin of Hawaiian tholeiites: trace element constraints. Am J Sci 280A: 794–819

  17. Macdonald GA (1944) Petrography of the Samoan Islands. Bull Geol Soc Am 55: 1333–1362

  18. Macdonald GA (1945) Petrography of the Wallis Islands. Bull Geol Soc Am 56: 861–872

  19. Macdonald GA (1968) Composition and origin of Hawaiian lavas. Geol Soc Am Mem 116: 477–522

  20. Macdonald GA, Katsura T (1964) Chemical composition of Hawaiian lavas. J Petrol 5: 82–133

  21. Macdonald GA, Abbott AT, Peterson FL (1983) Volcanoes in the Sea, the Geology of Hawaii, 2nd edition. University Press, Honolulu, p 517

  22. Minster JB, Jordan TH (1978) Present-day plate motions. J Geophys Res 83: 5331–5354

  23. Natland JH (1975) Petrologic studies of linear island chains: Samoan Islands and Line Islands. PhD Thesis, University of California, San Diego

  24. Natland JH (1980) The progression of volcanism in the Samoan linear volcanic chain. Am J Sci 280A: 709–735

  25. Natland JH, Turner DL (1986) Age progression and petrological development of Samoan shield volcanoes: evidence from K/Ar ages, lava compositions, and mineral studies. In: Brocher TM (ed) Investigations of the Northern Melanesian Borderland, AAPG Circum-Pacific Earth Sci Series, pp 138–171, in press

  26. Norrish K, Hutton JT (1969) An accurate X-ray spectrographic method for the analysis of a wide range of geologic samples. Geochim Cosmochim Acta 33: 431–451

  27. Norrish K, Chappell BW (1977) X-ray fluorescence spectroscopy. In: Zussman J (ed) Physical Methods in Determinative Mineralogy, 2nd edition. Academic Press, New York, pp 201–272

  28. Onuma K, Yagi K (1971) The join CaMgSi2O6-Ca2MgSiO6-CaTiAl2O6 in the system CaO-MgO-TiO2-SiO2 and its bearing on the titanpyroxenes. Min Mag 38: 471–480

  29. Sinton JM (1979) Ultramafic inclusions and high-pressure xenocrysts in submarine basanitoid, equatorial Mid-Atlantic Ridge. Contrib Mineral Petrol 70: 49–57

  30. Sinton JM, Johnson KTM, Price RC (1986) Petrology and geochemistry of volcanic rocks from the Northern Melanesian Borderland. In: Brocher TM (ed) Investigations of the Northern Melanesian Borderland, AAPG Circum-Pacific Earth Sci Series, pp 34–64

  31. Stearns HT (1945) Geology of the Wallis Islands. Bull Geol Soc Am 56: 849–860

  32. Stice GD (1968) Petrography of the Manu'a Islands. Contrib Mineral Petrol 19: 343–357

  33. Thompson RN (1974) Some high-pressure pyroxenes. Min Mag 39: 768–787

  34. Tracy RJ, Robinson P (1977) Zoned titanian augite in alkali olivine basalt from Tahiti and the nature of titanium substitution in augite. Am Mineral 62: 634–645

  35. Turner DL, Natland JH, Wright E (1983) New K/Ar ages of Samoan volcanoes. EOS Transactions of the Am Geophys Union 64: 905

  36. Wilkinson JFG (1975) Ultramafic inclusions and high-pressure megacrysts from a nephelinite sill, Nandewar Mountains, northeast New South Wales, and their bearing on the origin of certain iltramafic inclusions in volcanic rocks. Contrib Mineral Petrol 51: 235–262

  37. Winterer EL, Lonsdale PF, Matthews JL, Rosendahl BR (1974) Structure and acoustic stratigraphy of the Manihiki Plateau. Deep Sea Res 21: 793–814

  38. Yang HY (1975) Al- and Ti-rich clinopyroxene in the system CaMgSi2O6-CaAl2SiO6-CaTiAl2O6. Proc Geol Soc China 18: 48–57

  39. Yang HY (1976) The join CaMgSi2O6-CaAl2SiO6-CaTiAl2O6 and its bearings on the origin of Ca- and Al-rich inclusions in meteorites. Proc Geol Soc China 19: 107–126

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Correspondence to Kevin T. M. Johnson.

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Johnson, K.T.M., Sinton, J.M. & Price, R.C. Petrology of seamounts northwest of Samoa and their relation to Samoan volcanism. Bull Volcanol 48, 225–235 (1986).

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  • Volcanic Rock
  • Sedimentology
  • Geochemical Data
  • Compositional Characteristic
  • Volcanic Province