Skip to main content
Log in

Phase relations of a high-Mg basalt from the Aleutian Island Arc: Implications for primary island arc basalts and high-Al basalts

  • Published:
Contributions to Mineralogy and Petrology Aims and scope Submit manuscript

Abstract

Many volcanic centers in the Aleutian Islands have erupted lavas that range in composition from high-Mg basalt (MgO>9 wt%) to more fractionated and voluminous high-Al basalts and basaltic andesites. The petrogenetic relationships between these rock types and the composition of primary magmas has been vigorously debated. The phase relations of a typical high-Mg basalt from the Makushin volcanic field on Unalaska Island provide important constraints on petrogenetic models. Results of one-atmosphere and moderate-to high-pressure (5–20 kb) anhydrous experiments are similar to results obtained from primitive MORB. At low pressures olivine is the liquidus phase joined by plagioclase and clinopyroxene at progressively lower temperatures. Clinopyroxene is the second phase to crystallize at pressures greater than 5 kb and replaces olivine on the liquidus at approximately 10 kb. Above 10 kb the liquidus pyroxene is aluminous augite and orthopyroxene is the second phase to crystallize. Glasses in equilibrium with olivine and clinopyroxene at intermediate-pressure (5 to 10 kb) are similar in composition to high-Al basalt. Plagioclase is not involved and most likely does not become a liquidus phase until the liquid has evolved significantly. Although our studies do not confirm the primary nature of high-Mg basalts they do support a model in which high-Al basalts are generated by moderate amounts of crystal fractionation from more primitive (high Mg/Mg+Fe, lower Al2O3) basaltic magmas near the arc crust-mantle boundary.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Abbreviations

Ol :

olivine

Cpx :

Clinopyroxene

Pl :

plagioclase

L :

liquid

Sp :

spinel

Pig :

pigeonite

Opx :

Orthopyroxene

References

  • Arculus RJ, Johnson RW (1978) Criticism of generalized models for the magmatic evolution of arc-trench systems. Earth Planet Sci Lett 39:118–126

    Google Scholar 

  • Baker DR, Eggler DH (1983) Fractionation paths of Atka (Aleutians) high-alumina basalts: constraints from phase relations. J Volcanol Geothermal Res 18:387–404

    Google Scholar 

  • Bender JF, Hodges FN, Bence AE (1978) Petrogenesis of basalts from the project FAMOUS area: experimental study from 0 to 15 kbars. Earth Planet Sci Lett 41:277–302

    Google Scholar 

  • Bottinga Y, Weill D, Richet P (1982) Density calculations for silicate liquids. I. Revised method for aluminosilicate compositions. Geochim Cosmochim Acta 46:909–919

    Google Scholar 

  • Boyd FR, England JL (1960) Apparatus for phase equilibria measurements at pressures up to 50 kbars and temperatures up to 1750° C. J Geophys Res 65:741–748

    Google Scholar 

  • Brophy JG, Marsh BD (1986) On the origin of high-alumina arc basalt and the mechanics of melt extraction. J Petrol 27:763–789

    Google Scholar 

  • Byers F (1961) Petrology of three volcanic suites, Umnak and Bogoslof Islands, Aleutian Islands. Geol Soc Am Bull 79:93–128

    Google Scholar 

  • Byers FM Jr (1959) Geology of Unmak and Bogoslof Islands, Aleutian Islands, Alaska. US Geol Surv Bull 1028-L:267–369

    Google Scholar 

  • Coats RR, Nelson WH, Lewis RQ, Powers HA (1961) Geological reconnaissance of Kiska Island, Aleutian Islands, Alaska. US Geol Surv Bull 1028-R

  • Conrad WK, Kay RW (1984) Ultramafic and mafic inclusions from Adak Island: crystallization history and implications for the nature of primary magmas and crustal evolution in the Aleutian arc. J Petrol 25:88–125

    Google Scholar 

  • Crawford AJ, Falloon TJ, Eggins S (1987) Island arc high-alumina basalts are not primary, eclogite-derived magmas. Contrib Mineral Petrol

  • DeBari SM (1984) The petrology of ultramafic xenoliths from Adagdak volcano, Adak Island, Alaska: evidence for lower crust/upper mantle accumulation. Unpublished senior thesis, Cornell University, New York, p 65

    Google Scholar 

  • DeLong SE, Perfit MR, McCulloch MT, Ach J (1985) Magmatic evolution of Semisopochnoi Island, Alaska: trace element and isotopic constraints. J Geol 93:609–618

    Google Scholar 

  • Drewes H, Fraser GF, Snyder GL, Barnett HF (1961) Geology of Unalaska Island and adjacent insular shelf, Aleutian Islands, Alaska. Bull US Geol Surv 1028-S:583–676

    Google Scholar 

  • Eggler DH (1972) Water-saturated and undersaturated melting relations in a Paricutan andesite and an estimate of water content in the natural andesite. Contrib Mineral Petrol 34:261–271

    Google Scholar 

  • Elthon D (1986) High-pressure crystal-liquid fractionation of basaltic magmas: a phase-equilibrium framework. Lunar Planet Sci Conf XVII, pp 206–207

  • Elthon D, Scarfe CM (1984) High-pressure phase equilibria of a high-magnesia basalt and the genesis of primary oceanic basalts. Am Mineral 69:1–15

    Google Scholar 

  • Fisk MR, Bence AE (1980) Experimental crystallization of chrome spinel in FAMOUS basalt 527-1. Earth Planet Sci Lett 48:113–123

    Google Scholar 

  • Fujii T, Bougault H (1983) Melting relations of a magnesian abyssal tholeiite and the origin of MORBs. Earth Planet Sci Lett 62:283–295

    Google Scholar 

  • Fujii T, Scarfe CM (1985) Composition of liquids coexisting with spinel lherzolite at 10 kbar and the genesis of MORBs. Contrib Mineral Petrol 90:18–28

    Google Scholar 

  • Gill JB (1981) Orogenic Andesites and Plate Tectonics. Springer, Berlin Heidelberg New York, pp 390

    Google Scholar 

  • Green TH (1982) Anatexis of mafic crust and high pressure crystallization of andesite. In: Thorpe RS (ed) Andesites. Wiley and Sons, New York, pp 465–487

    Google Scholar 

  • Green DH, Hibberson WO (1970) Experimental duplication of conditions of precipitation of high pressure phenocrysts in a basaltic magma. Phys Earth Planet Interiors 3:247–254

    Google Scholar 

  • Green TH, Ringwood AE (1968) Genesis of the calc-alkaline igneous rock suite. Contrib Mineral Petrol 18:105–162

    Google Scholar 

  • Grove TL, Baker MB (1984) Phase equilibrium controls on the tholeiitic versus calc-alkaline differentiation trends. J Geophys Res 89:3253–3274

    Google Scholar 

  • Grow JA (1973) Crustal and upper mantle structure of the central Aleutian arc. Geol Soc Am Bull 84:2169–2192

    Google Scholar 

  • Hill R, Roeder P (1974) The crystallization of spinel from basaltic liquid as a function of oxygen fugacity. J Geol 82:709–729

    Google Scholar 

  • Huppert HE, Sparks RSJ (1985) Cooling and contamination of mafic and ultramafic magmas during ascent through continental crust. Earth Planet Sci Lett 74:371–386

    Google Scholar 

  • Jakes P, Gill JB (1970) Rare earth elements and the island arc tholeiite series. Earth Planet Sci Lett 9:17–28

    Google Scholar 

  • Johnston AD (1986) Anhydrous P-T phase relations of near-primary high-alumina basalt from the South Sandwich Islands: implications for the origin of island arc and the tonalite-trondhjemite series rocks. Contrib Mineral Petrol 92:368–382

    Google Scholar 

  • Kay RW (1977) Geochemical constraints on the origin of Aleutian magmas. In: Talwani M, Pitman WC (eds) Island arcs, deep sea trenches and back-arc basins. Maurice Ewing Series, AGU, Washington, pp 229–242

    Google Scholar 

  • Kay SM, Kay RW (1985a) Role of crystal cumulates and the ocean crust in the formation of the lower crust of the Aleutian arc. Geology 13:461–464

    Google Scholar 

  • Kay SM, Kay RM (1985b) Aleutian tholeiitic and calc-alkaline magma. Series I. The mafic phenocrysts. Contrib Mineral Petrol 90:276–290

    Google Scholar 

  • Kay SM, Kay RW, Citron GP (1982) Tectonic controls of Aleutian tholeiitic and calc-alkaline magmatism. J Geophys Res 87:4051–4072

    Google Scholar 

  • Kuno H (1966) Lateral variation of basalt magma type across continental magmas and island arcs. Bull Volcanol 29:195–222

    Google Scholar 

  • Kushiro I, Thompson RN (1972) Origin of some abyssal tholeiites from the Mid-Atlantic Ridge. Carnegie Inst Washington 71:403–406

    Google Scholar 

  • LeMaitre R (1981) GENMIX — A generalized petrological mixing model program. Computers Geosci 7:229–247

    Google Scholar 

  • Luhr JF, Carmichael ISE (1985) Jorullo Volcano Michoacán Mexico (1759–1774): The earliest stages of fractionation in cale-alkaline magmas. Contrib Mineral Petrol 90:142–161

    Google Scholar 

  • Marsh BD (1982) The Aleutians. In: Thorpe RS (ed) Andesites. John Wiley & Sons, New York, pp 9–114

    Google Scholar 

  • McBirney AR (1978) Volcanic evolution of the Cascade Range. Ann Rev Earth Planet Sci 6:437–456

    Google Scholar 

  • McBirney AR, Baker BH, Wilson RH (1985) Liquid Fractionation. Part I. Basic principles and experimental simulations. J Volcanol Geotherm Res 24:1–24

    Google Scholar 

  • McCulloch MT, Perfit MR (1981) 143Nd/133Nd, 87Sr/86Sr and trace element constraints on the petrogenesis of Aleutian island arc magmas. Earth Planet Sci Lett 56:167–179

    Google Scholar 

  • Myers JD, Marsh BD, Sinha AK (1985) Strontium isotopic and selected trace element variations between two Aleutian volcanic centers (Adak and Atka): implications for the development of arc volcanic plumbing systems. Contrib Mineral Petrol 91:221–234

    Google Scholar 

  • Myers JD, Marsh BD, Sinha AK (1986) Geochemical and strontium isotopic characteristics of parental Aleutian arc magmas: evidence from the basaltic lavas of Atka. Contrib Mineral Petrol 94:1–11

    Google Scholar 

  • Nehru CE, Wyllie PJ (1975) Compositions of St. Paul's peridotite partially melted at 20 kbars. J Geol 83:455–471

    Google Scholar 

  • Nicholls IA, Ringwood AE (1973) Effect of water on olivine stability in tholeiites and production of SiO2 — saturated magmas in the island arc environment. J Geol 81:285–300

    Google Scholar 

  • Nicholls IA, Whitford DJ (1976) Primary magmas associated with Quaternary volcanism in the western Sunda arc, Indonesia. In: Johnson RW (ed) Volcanism in Australasia. pp 77–90

  • Nye C (1983) Petrology and geochemistry of Okmok and Wrangell volcanoes, Alaska. PhD thesis, University of California, Santa Cruz, pp 208

    Google Scholar 

  • Nye CJ, Reid MR (1986) Geochemistry of primary and least fractionated lavas from Okmok volcano, central Aleutians: implications for arc magma genesis. J Geophys Res 91:271–287

    Google Scholar 

  • O'Neil H St C, Hibberson W (1981) Salt cells and their pressure calibration for the 1/2″ piston cylinder apparatus. Aust Nat Univ RSES Annual Report, pp 149–150

  • Perfit MR (1977) The petrochemistry of igneous rocks from the Cayman Trench and the Captains Bay pluton, Unalaska Island: their relation to tectonic processes at plate margins. PhD thesis, Columbia University, New York, pp 237

    Google Scholar 

  • Perfit MR (1978) The petrochemistry and strontium isotopic composition of mafic basalts from the Aleutian Islands. Abstr Geol Soc Am 10:470

    Google Scholar 

  • Perfit MR, Gust DA (1981) Petrochemistry and experimental crystallization of basalts from Aleutian Islands, Alaska. IAVCEI Symposium on Arc Volcanism, Tokyo, pp 288–289

  • Perfit MR, Gust DA, Bence AE, Arculus RJ, Taylor SR (1980a) Chemical characteristics of island-arc basalts: implications for mantle sources. Chem Geol 30:227–256

    Google Scholar 

  • Perfit MR, Brueckner H, Lawrence JR, Kay RW (1980b) Trace element and isotopic variations in a zoned pluton and associated volcanic rocks, Unalaska Island, Alaska: a model for fractionation in the Aleutian calc-alkaline suite. Contrib Mineral Petrol 73:69–87

    Google Scholar 

  • Ramsay WRN, Crawford AJ, Foden JD (1984) Field setting, mineralogy, chemistry, and genesis of arc picrites. New Georgia, Solomon Islands. Contrib Mineral Petrol 88:386–402

    Google Scholar 

  • Spence W (1977) The Aleutian arc: tectonic blocks, episodic subduction strain diffusion and magma generation. J Geophys Res 82:213–230

    Google Scholar 

  • Stopler E (1980) A phase diagram for mid-ocean ridge basalts: preliminary results and implications for petrogenesis. Contrib Mineral Petrol 74:13–27

    Google Scholar 

  • Stopler E, Walker D (1980) Melt density and the average composition of basalt. Contrib Mineral Petrol 74:7–12

    Google Scholar 

  • Swanson SE (1983) Mineralogy and fractionation in Makushin volcanic field, Unalaska Island, Alaska. Abst Geol Soc Am 15:703

    Google Scholar 

  • Swanson SE, Kay SM, Brearly M, Scarfe C (1986) Mantle xenoliths — Pacific Plate and surrounding regions — Kurile — Kamchatka and western Alaska. In: Mantle xenoliths. Nixon PN (ed) John Wiley and Sons, New York

    Google Scholar 

  • Tatsumi Y, Sakuyama M, Fukuyama H, Kushiro I (1983) Generation of arc basalts magmas and thermal structure of the mantle wedge in subduction zones. J Geophys Res 88:5815–5825

    Google Scholar 

  • Walker D, Shibata T, DeLong SE (1979) Abyssal tholeiites from the oceanographer fracture zone. Contrib Mineral Petrol 70:111–125

    Google Scholar 

  • Wyllie PJ (1982) Subduction products according to experimental prediction. Bull Geol Soc Am 93:468–476

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gust, D.A., Perfit, M.R. Phase relations of a high-Mg basalt from the Aleutian Island Arc: Implications for primary island arc basalts and high-Al basalts. Contr. Mineral. and Petrol. 97, 7–18 (1987). https://doi.org/10.1007/BF00375210

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00375210

Keywords

Navigation