Petrology of arc volcanic rocks and their origin by mantle diapirs

https://doi.org/10.1016/0377-0273(83)90013-6Get rights and content

Abstract

Calc-alkalic chemical trends characteristic of arc volcanic rocks mainly result from three mechanisms which act additively: (1) fractional crystallization involving separation of titanomagnetite; (2) selective concentration of plagioclase phenocrysts and selective depletion of titanomagnetite phenocryst compared with the actually fractionated proportion; and (3) mixing of magmas on continuous fractionation trends. The association of calc-alkalic and tholeiitic trends in a single composite volcano may not represent different fractional crystallization processes or different chemistries of primary magmas, but the calc-alkalic chemical trend can be considered as a mixing trend resulting from mixing of various magmas on associated tholeiitic chemical trends. Chemical variations of most arc volcanic rocks, including calc-alkalic ones, can accordingly be essentially accounted for by the low-pressure fractional crystallization of phenocrystic phases from primary basaltic magmas.

Crystallization sequences of arc magmas which are strongly dependent on water content in magmas are deduced from the phenocryst assemblages. The crystallization sequence changes laterally across-arc, suggesting increasing water contents in magmas toward the back-arc side, as is also seen for other incompatible elements such as K and Rb. Systematic differences in the characteristic crystallization sequence are also observed among arcs, roughly correlating with the crustal thickness. Water content in magma, like other incompatible elements, tends to increase with increasing crustal thickness. The variation of incompatible elements including water roughly represents that of the degree of partial melting of the upper mantle, which is broadly controlled by the crustal thickness.

The variation of water content indicates that arc magmas are not saturated with water during differentiation to late differentiates such as dacite or rhyolite. This strongly constrains the maximum water contents in primary basaltic magma, at most 2.5 wt.%. This value suggests that magma generation beneath arcs is dependent on dry solidus of peridotite. Diapiric uprise of the hot deeper mantle and associated adiabatic decompression would be necessary for mantle peridotite to attain the temperature as high as dry solidus. Diapirs that begin to rise from the subduction zone may stop at or near the crust-mantle boundary because of the surrounding density change, and their degree of partial melting is roughly controlled by their stopped depth assuming their similar temperature. Across-arc variation is also explained by the stopped depth of diapirs, but is not controlled by crustal thickness.

References (104)

  • Y. Masuda et al.

    Trace element variations in the volcanic rocks from the Nasu zone, northeast Japan

    Earth Planet. Sci. Lett.

    (1979)
  • Y. Matsuhisa

    Oxygen isotopic compositions of volcanic rocks from the East Japan island are and their bearing on petrogenesis

    J. Volcanol. Geotherm. Res.

    (1979)
  • M.R. Perfit et al.

    Chemical characteristics of island arc basalts: implications for mantle sources

    Chem. Geol.

    (1980)
  • H. Ramberg

    Mantle diapirism and its tectonic and magmagenetic consequences

    Phys. Earth Planet. Inter.

    (1972)
  • M. Sakuyama

    Lateral variations of H2O contents in Quaternary magmas of northeastern Japan

    Earth Planet. Sci. Lett.

    (1979)
  • M. Sakuyama

    Evidence of magma mixing: petrological study of Shirouma-Oike calc-alkaline andesite volcano, Japan

    J. Volcanol. Geotherm. Res.

    (1979)
  • T. Sekine et al.

    Water saturated phase relations of some andesites with application to the estimation of the initial temperature and water pressure at the time of eruption

    Geochim. Cosmochim. Acta

    (1979)
  • Y. Tatsumi et al.

    Existence of andesitic primary magma: an example from southwest Japan

    Earth Planet. Sci. Lett.

    (1981)
  • T. Ui et al.

    Relationship between chemical composition of Japanese island-arc volcanic rocks and gravimetric data

    Tectonophysics

    (1978)
  • P.J. Wyllie

    Crustal anatexis: An experimental review

    Tectonophysics

    (1977)
  • J.C. Allen et al.

    Amphiboles in andesite and basalt: I. Stability as a function of P-T-fO2

    Am. Mineral.

    (1975)
  • R.J. Arculus et al.

    Island-arc magma sources: a geochemical assessment of the roles of slab derived components and crustal contamination

    Geochem. J.

    (1981)
  • M.G. Best

    Petrology of the Guadalupe igneous complex, south-western Sierra Nevada Foothills, California

    J. Geol.

    (1963)
  • D.H. Blake

    Post-Miocene volcanoes in Bougainville Island, Territory of Papua and New Guinea

    Bull. Volcanol.

    (1968)
  • D.H. Blake et al.

    Geology of Bougainville and Buka Islands, New Guinea

    Bur. Miner. Resour., Geol. Geophys. (Aust.) Bull.

    (1967)
  • F.M. Byers

    Geology of Umnak and Bogoslof islands, Aleutian Islands, Alaska

    U.S. Geol. Surv., Bull.

    (1959)
  • R.G. Cawthorn

    Degrees of melting in mantle diapirs and the origin of ultrabasic liquids

    Earth Planet. Sci. Lett.

    (1975)
  • R.G. Cawthorn

    Calcium-poor pyroxene reaction relations in calc-alkaline magmas

    Am. Mineral.

    (1976)
  • R.G. Cawthorn

    Melting relations in part of the system CaO-MgO-Al2O3-SiO2-Na2O-H2O under 5 kb pressure

    J. Petrol.

    (1976)
  • R.G. Cawthorn et al.

    A petrogenetic model for the origin of the calc-alkaline suite of Grenada, Lesser Antilles

    J. Petrol.

    (1973)
  • R.G. Cawthorn et al.

    Amphibole fractionation in calc-alkaline magma genesis

    Am. J. Sci.

    (1976)
  • R.R. Coats

    Magmatic differentiation in Tertiary and Quaternary volcanic rocks from Adak and Kanaga islands, Aleutian Islands, Alaska

    Geol. Soc. Am. Bull.

    (1952)
  • W.B. Dallwitz et al.

    Clinoenstatite in a volcanic rock from the Cape Vogel area, Papua

    J. Petrol.

    (1966)
  • D.H. Eggler

    Water-saturated and undersaturated melting relations in a Paricutin andesite and an estimate of water content in the natural magma

    Contrib. Mineral. Petrol.

    (1972)
  • D.H. Eggler et al.

    Crystallization and fractionation trends in the system andesite-H2O-CO2-O2 at pressure to 10 kb

    Geol. Soc. Am. Bull.

    (1973)
  • J.C. Eichelberger

    Origin of andesite and dacite; Evidence of mixing at Glass Mountain in California and at other circum-Pacific volcanoes

    Geol. Soc. Am. Bull.

    (1975)
  • J.C. Eichelberger

    Andesites in island arcs and continental margins; Relationship to crustal evolution

    Bull. Volcanol.

    (1978)
  • A. Ewart et al.

    Quaternary acid magma in New Zealand

    Contrib. Mineral. Petrol.

    (1975)
  • N.H. Fisher

    Catalogue of the active volcanoes of the world including solfatara fields, Part V, Melanesia

  • P.W. Francis et al.

    The San Pedro and San Pabro volcanoes of northern Chile and their hot avalanche deposits

    Geol. Rundsch.

    (1974)
  • F.A. Frey et al.

    Integrated models of basalt petrogenesis; a study of quartz tholeiite to olivine melilitites from southeastern Australia utilizing geochemical and experimental petrological data

    J. Petrol.

    (1978)
  • A. Fujinawa

    Geology and petrology of Adatara volcano

    J. Jpn. Assoc. Miner. Petrol., Econ. Geol.

    (1980)
  • J.B. Gill

    Orogenic Andesites and Plate Tectonics

  • D.H. Green et al.

    The genesis of basaltic magmas

    Contrib. Mineral. Petrol.

    (1967)
  • T.H. Green et al.

    Genesis of the calc-alkalic igneous rock suite

    Contrib. Mineral. Petrol.

    (1968)
  • D.L. Hamilton et al.

    The solubility of water and effect of oxygen fugacity and water content on crystallization in mafic magmas

    J. Petrol.

    (1964)
  • G. Hantke et al.

    Catalogue of the active volcanoes of the world including solfatara fields

  • R.T. Helz

    Phase relations of basalts in their melting range at PH2O = 5 kb as a function of oxygen fugacity. Part I. Mafic phases

    J. Petrol.

    (1973)
  • T. Ichimura

    Geological investigations on the Zao volcanoes. I. Goshiki-dake, a central cone of the Zao Proper

    Bull. Earthq. Res. Inst.,Tokyo Univ.

    (1951)
  • T. Ichimura

    Geological investigations on the Zao volcanoes. II. Aoso volcano

    Bull. Earthq. Res. Inst., Tokyo Univ.

    (1953)
  • Cited by (59)

    • Light rare earth element depleted to enriched basaltic flows from 2.8 to 2.7 Ga greenstone belts of the Uchi Subprovince, Ontario, Canada

      2006, Chemical Geology
      Citation Excerpt :

      The two samples with Th/Ce close to or greater than 0.1 do not have lower Zr/Nb combined with greater La/Ybn compared to the remainder of the population, as would be expected for siliceous melts of sediments on a slab (Fig. 10; e.g., Elburg et al., 2002, and references therein). A decrease in the degree of partial melting is a consequence of a lower flux of water to the mantle wedge, longer fluid pathways to the zone of melting and greater depth of melting (Sakuyama, 1983; Tatsumi et al., 1991; Green, 1994; Barragan et al., 1998). There is a trend of increasing Nb content and La/Ybn, but decreasing Zr/Nb, from LKS through MKS to the alkaline lavas in this study (Tables 3 and 4).

    • Geochemical characteristics of Sabalan volcanic rocks in Northwestern Iran

      2019, Bulletin of the Mineral Research and Exploration
    View all citing articles on Scopus
    View full text