A Geochemical Classification for Granitic Rocks

Ague, J. J. & Brimhall, G. H. (1988). Regional variations in bulk chemistry, mineralogy, and the compositions of mafic and accessory minerals in the batholiths of California. Geological Society of America Bulletin100, 891–911.

Altherr, R., Holl, A., Hegner, E., Langer, C. & Kreuzer, H. (2000). High-potassium, calc-alkaline I-type plutonism in the European Variscides: northern Vosges (France) and northern Schwartzwald (Germany). Lithos50, 51–73.

Anderson, J. G. C. (1937). The Etive granite complex. Journal of the Geological Society, London93, 487–533.

Anderson, J. L. (1980). Mineral equilibria and crystallization conditions in the late Precambrian Wolf River rapakivi massif, Wisconsin. American Journal of Science280, 298–332.

Anderson, J. L. (1983). Proterozoic anorogenic granite plutonism of North America. In: Mederis, L. G., Byers, C. W., Mickelson, D. M. & Shanks, W. C. (eds) Proterozoic Geology, Selected Papers from an International Proterozoic Symposium. Geological Society of America, Memoir161, 133–154.

Anderson, J. L. & Bender, E. E. (1989). Nature and origin of Proterozoic A-type granitic magmatism in the southwestern United States. Lithos23, 19–52.

Anderson, J. L. & Cullers, R. L. (1978). Geochemistry and evolution of the Wolf River batholith, a late Precambrian rapakivi massif in northern Wisconsin, USA. Precambrian Research7, 287–324.

Anderson, J. L. & Cullers, R. L. (1990). Middle to upper crustal plutonic construction of a magmatic arc; an example from the Whipple Mountains metamorphic core complex. In: Anderson, J. L. (ed.) The Nature and Origin of Cordilleran Magmatism. Geological Society of America, Memoir174, 47–69.

Anderson, J. L. & Thomas, W. M. (1985). Proterozoic anorogenic two-mica granites: Silver Plume and St. Vrain batholiths of Colorado. Geology13, 177–180.

Arnaud, N. O., Vidal, P., Tapponnier, P., Matte, P. & Deng, W. M. (1992). The high K2O volcanism of northwestern Tibet: geochemistry and tectonic implications. Earth and Planetary Science Letters111, 351–367.

Bachelor, R. A. & Bowden, P. (1985). Petrologic interpretation of granitoid rocks series using multicationic parameters. Chemical Geology48, 43–55.

Barbarin, B. (1990). Granitoids: main petrogenetic classification in relation to origin and tectonic setting. Geological Journal25, 227–238.

Barbarin, B. (1999). A review of the relationships between granitoid types, their origins and their geodynamic environments. Lithos46, 605–626.

Barker, F., Wones, D. R., Sharp, W. N. & Desborough, G. A. (1975). The Pikes Peak batholith, Colorado Front Range and a model for the origin of the gabbro–anorthosite–syenite–potassic granite suite. Precambrian Research2, 97–160.

Barker, F., Arth, J. G. & Millard, H. J. (1979). Archean trondhjemites of the southwestern Big Horn Mountains, Wyoming: a preliminary report. In: Barker, F. (ed.) Trondhjemites, Dacites, and Related Rocks. Amsterdam: Elsevier, pp. 401–414.

Barker, F., Millard, H. T. & Lipman, P. W. (1979). Four low-K siliceous rocks of the western U.S.A. In: Barker, F. (ed.) Trondhjemites, Dacites, and Related Rocks. Amsterdam: Elsevier, pp. 415–433.

Barth, A. P. (1990). Mid-crustal emplacement of Mesozoic plutons, San Gabriel Mountains, California, and implications for the geologic history of the San Gabriel terrane. In: Anderson, J. L. (ed.) The Nature and Origin of Cordilleran Magmatism. Geological Society of America, Memoir174, 33–45.

Barton, J. M., Jr (1975). Rb–Sr isotopic characteristics and chemistry of the 3·6 b.y. Hebron gneiss, Labrador. Earth and Planetary Science Letters27, 427–435.

Bateman, P. C. (1961). Granitic formations in the east–central Sierra Nevada near Bishop, California. Geological Society of America Bulletin72, 1521–1538.

Bateman, P. C. & Chappell, B. W. (1979). Crystallization, fractionation, and solidification of the Tuolumne intrusive series, Yosemite National Park, California. Geological Society of America Bulletin90, 465–482.

Bateman, P. C. & Dodge, F. C. W. (1970). Variations of major chemical constituents across the central Sierra Nevada batholith. Geological Society of America Bulletin81, 409–420.

Bea, F. (1996). Residence of REE, Y, Th, and U in granites and crustal protoliths, implications for the chemistry of crustal melts. Journal of Petrology37, 521–552.

Bowden, P. & Turner, D. C. (1974). Peralkaline and associated ring-complexes in the Nigeria–Niger province, West Africa. In: Sørensen, H. (ed.) The Alkaline Rocks. New York: John Wiley, pp. 330–351.

Chappell, B. W. & White, A. J. R. (1974). Two contrasting granite types. Pacific Geology8, 173–174.

Collins, B. W. (1996). Lachlan fold belt granitoids; products of three-component mixing. In: Brown, M., Candela, P. A., Peck, D. L., Stephens, W. E., Walker, R. J. & Zen, E-an (eds) Third Hutton Symposium on the Origin of Granites and Related Rocks. Geological Society of America, Special Papers315, 171–181.

Collins, B. J., Beams, S. D., White, A. J. R. & Chappell, B. W. (1982). Nature and origin of A-type granites with particular reference to southeastern Australia. Contributions to Mineralogy and Petrology80, 189–200.

Cullers, R. L., Koch, R. J. & Bickford, M. E. (1981). Chemical evolution of magmas in the Proterozoic terrane of the St. Francois Mountains, southeastern Missouri; 1. Trace element data. Journal of Geophysical Research86, 10388–10401.

Cullers, R. L., Griffin, T., Bickford, M. E. & Anderson, J. L. (1992). Origin and chemical evolution of the 1360 Ma-old San Isabel batholith, Wet Mountains, Colorado, USA: a mid-crustal granite of anorogenic affinities. Geological Society of America Bulletin104, 316–328.

De la Roche, H., Leterrier, J., Grandclaude, P. & Marchal, M. (1980). A classification of volcanic and plutonic rocks using R1,R2-diagrams and major element analysis—its relationships with current nomenclature. Chemical Geology29, 183–210.

Dickenson, W. R. (1975). Potash–depth (K–h) relations in continental margins and intra-oceanic magmatic arcs. Geology3, 53–56.

Duchesne, J.-C. & Wilmart, E. (1997). Igneous charnockites and related rocks from the Bjerkreim-–Sokndal layered intrusion (southwest Norway): a jotunite (hypersthene monzodiorite)-derived A-type granitoid suite. Journal of Petrology38, 337–369.

Duchesne, J.-C., Berza, T., Liégeois, J.-P. & Auwera, J. V. (1998). Shoshonitic liquid line of descent from diorite to granite: the Late Precambrian post-collisional Tismana pluton (South Carpathians, Romania). Lithos45, 281–303.

Eby, G. N. (1990). The A-type granitoids; a review of their occurrence and chemical characteristics and speculations on their petrogenesis. Lithos26, 115–134.

Eggler, D. H. (1968). Virginia Dale Precambrian ring-dike complex, Colorado–Wyoming. Geological Society of America Bulletin79, 1545–1564.

Ellis, D. J. & Thompson, A. B. (1986). Subsolidus and partial melting reactions in the quartz-excess CaO + MgO + Al2O3 + SiO2 + H2O system under water-excess and water-deficient conditions to 10 kb: some implications for the origin of peraluminous melts from mafic rocks. Journal of Petrology27, 91–121.

England, P. C. & Thompson, A. B. (1984). Pressure–temperature–time paths of regional metamorphism; I. Heat transfer during the evolution of regions of thickened continental crust. Journal of Petrology25, 894–928.

Erikson, E. H. (1969). Petrology of the composite Snoqualmie batholith, Central Cascade mountains, Washington. Geological Society of America Bulletin80, 2213–2236.

Erikson, E. H. (1977). Petrology and petrogenesis of the Mount Stuart batholith—plutonic equivalent of the high-aluminum basalt association? Contributions to Mineralogy and Petrology60, 183–207.

Ferguson, H. (1970). The differentiation of Agpaitic magmas: the Ilimaussaq intrusion, south Greenland. Canadian Mineralogist10, 335–394.

Ferré, E. C., Caby, R., Peucat, J. J., Capdevila, R. & Monié, P. (1998). Pan-African post-collisional ferro-potassic granite and quartz-monzonite plutons of Eastern Nigeria. Lithos45, 255–278.

Frost, B. R. & Lindsley, D. H. (1991). The occurrence of Fe–Ti oxides in igneous rocks. In: Lindsley, D. H. (ed.), Oxide Minerals: Petrologic and Magnetic Significance. Mineralogical Society of America, Reviews in Mineralogy25, 433–486.

Frost, B. R., Lindsley, D. H. & Andersen, D. J. (1988). Fe–Ti oxide–silicate equilibria: assemblages with fayalitic olivine. American Mineralogist73, 727–740.

Frost, B. R., Frost, C. D., Hulsebosch, T. P. & Swapp, S. M. (2000). Origin of the charnockites of the Louis Lake batholith, Wind River Range, Wyoming. Journal of Petrology41, 1759–1776.

Frost, C. D. & Frost, B. R. (1997). High-K, iron-enriched rapakivi-type granites: the tholeiite connection. Geology25, 647–650.

Frost, C. D., Frost, B. R., Chamberlain, K. R. & Edwards, B. R. (1999). Petrogenesis of the 1·43 Ga Sherman batholith, SE Wyoming: a reduced rapakivi-type anorogenic granite. Journal of Petrology40, 1771–1802.

Fuhrman, M. L., Frost, B. R. & Lindsley, D. H. (1988). The petrology of the Sybille Monzosyenite, Laramie Anorthosite Complex, Wyoming. Journal of Petrology29, 699–729.

Gardiner, C. I. & Reynolds, S. H. (1931). The Loch Doon ‘granite’ area, Galloway. Journal of the Geological Society, London88, 1–34.

Gardiner, C. I. & Reynolds, S. H. (1937). The Cairnsmore of Fleet Granite and its metamorphic aureole. Geological Magazine74, 289–300.

Gastil, G., Diamond, J., Knaack, C., Walawender, M., Marshall, M., Boyles, C., Chadwick, B. & Erskine, B. (1990). The problem of the magnetite/ilmenite boundary in southern and Baja California. In: Anderson, J. L. (ed.) The Nature and Origin of Cordilleran Magmatism. Geological Society of America, Memoir174, 19–32.

Hall, A. (1966). A petrogenetic study of the Rosses granite complex, Donegal. Journal of Petrology7, 202–220.

Hall, A. (1972). New data on the composition of Caledonian granites. Mineralogical Magazine38, 847–862.

Haslam, H. W. (1968). The crystallization of intermediate and acid magmas at Ben Nevis, Scotland. Journal of Petrology9, 84–104.

Hietanen, A. (1963). Idaho Batholith near Pierce and Bungalow Clearwater County, Idaho. US Geological Survey, Professional Papers344-D, 42 pp.

Hietanen, A. (1976). Metamorphism and Plutonism, Feather River Area, California. US Geological Survey, Professional Papers920, 30 pp.

Holtz, F. & Barbey, W. (1991). Genesis of peraluminous granites II. Mineralogy and chemistry of the Tourem complex (North Portugal). Sequential melting vs restite unmixing. Journal of Petrology32, 959–978.

Holtz, F. & Johannes, W. (1991). Genesis of peraluminous granites I. Experimental investigation of melt compositions at 3 and 5 kb and various H2O activities. Journal of Petrology32, 935–958.

Hotz, P. E. (1971). Plutonic Rocks of the Klamath Mountains, California and Oregon. US Geological Survey, Professional Paper684-B, 20 pp.

Hurst, R. W., Bridgwater, D., Collerson, K. D. & Wetherill, G. W. (1975). 3600-m.y. Rb–Sr ages from very Early Archean gneisses from Saglek Bay, Labrador. Earth and Planetary Science Letters27, 393–403.

Hyndman, D. W. (1984). A petrographic and chemical section through the northern Idaho batholith. Journal of Geology92, 83–102.

Inger, S. & Harris, N. (1993). Geochemical constraints on leucogranite magmatism in the Langthan Valley, Nepal Himalaya. Journal of Petrology34, 345–368.

Ishihara, S. (1977). The magnetite-series and ilmenite-series granitic rocks. Mining Geology27, 293–305.

Ishihara, S. (1981). The granitoid series and mineralization. Economic Geology, 75th Anniversary Volume458–484.

John, B. E. & Wooden, J. (1990). Petrology and geochemistry of the metaluminous to peraluminous Chemehuevi Mountains Plutonic suite, southeastern California. In: Anderson, J. L. (ed.) The Nature and Origin of Cordilleran Magmatism. Geological Society of America, Memoir174, 71–98.

Johnson, K., Barnes, C. G. & Miller, C. A. (1997). Petrology, geochemistry and genesis of high-Al tonalite and trondhjemites of the Cornucopia stock, Blue Mountains, northeastern Oregon. Journal of Petrology38, 1585–1611.

Kilpatrick, J. A. & Ellis, D. J. (1992). C-type magmas: igneous charnockites and their extrusive equivalents. Transactions of the Royal Society of Edinburgh: Earth Sciences83, 155–164.

King, P. L., White, A. J. R., Chappell, B. W. & Allen, C. M. (1997). Characterization and origin of aluminous A-type granites from the Lachlan fold belt, southeastern Australia. Journal of Petrology38, 371–391.

Kolker, A. & Lindsley, D. H. (1989). Geochemical evolution of the Maloin Ranch pluton, Laramie anorthosite complex, Wyoming: petrology and mixing relations. American Mineralogist74, 307–324.

Landenberger, B. & Collins, W. J. (1996). Derivation of A-type granites from a dehydrated charnockitic lower crust: evidence from the Chaelundi complex. Eastern Australia. Journal of Petrology37, 145–170.

Larsen, E. S. (1948). Batholith and Associated Rocks of Corona, Elsinore and San Luis Rey Quadrangles Southern California. Geological Society of America, Memoir29, 182 pp.

Leake, B. E. (1974). The crystallization history and mechanism of emplacement of the western part of the Galway Granite, Connemara, Western Ireland. Journal of Petrology, 39, 498–513.

Le Fort, P. (1981). Manaslu leucogranite: a collision signature of the Himalaya, a model for its genesis and emplacement. Journal of Geophysical Research86, 10545–10568.

Le Fort, P., Cuney, M., Deniel, C., France-Lanord, C., Sheppard, S. M. F., Upreti, E. N. & Vidal, P. (1987). Crustal generation of the Himalayan leucogranites. Tectonophysics134, 39–57.

Lewis, R. S., Kiilsgaard, T. H., Bennett, E. H. & Hall, W. E. (1987). Lithologic and chemical characteristics of the central and southeastern part of the southern lobe of the Idaho batholith. US Geological Survey, Professional Papers1436, 171–196.

Liégeois, J.-P., Navez, J., Hertogen, J. & Black, R. (1998). Contrasting origin of post-collisional high-K calc-alkaline and shoshonitic versus alkaline and peralkaline granitoids: the use of sliding normalization. Lithos45, 1–28.

Liggett, D. L. (1990). Geochemistry of the garnet-bearing Tharps Peak granodiorite and its relation to other members of the Lake Kanweah intrusive suite, southwestern Sierra Nevada, California. In: Anderson, J. L. (ed.) The Nature and Origin of Cordilleran Magmatism. Geological Society of America, Memoir174, 225–236.

Loiselle, M. C. & Wones, D. S. (1979). Characteristics and origin of anorogenic granites. Geological Society of America, Abstracts with Programs11, 468.

Maniar, P. D. & Piccoli, P. M. (1989). Tectonic discrimination of granitoids. Geological Society of America Bulletin101, 635–643.

McDougall, I. (1962). Differentiation of the Tasmanian dolerites: Red Hill dolerite–granophyre association. Geological Society of America Bulletin73, 279–316.

Miller, C. F. (1985). Are strongly peraluminous magmas derived from pelitic sedimentary sources? Journal of Geology93, 673–689.

Miller, C. F., Wooden, J. F., Bennett, V. C., Wright, J. E., Solomon, G. C. & Hurst, R. W. (1990). Petrogenesis of the composite peraluminous–metaluminous Old Woman–Piute Range batholith, southeastern California; isotopic constraints. In: Anderson, J. L. (ed.) The Nature and Origin of Cordilleran Magmatism. Geological Society of America, Memoir174, 99–109.

Mitchell, R. H. & Platt, R. G. (1978). Mafic mineralogy of ferroaugite syenite from the Coldwell alkaline complex, Ontario, Canada. Journal of Petrology19, 627–651.

Miyashiro, A. (1970). Volcanic rock series in island arcs and active continental margins. American Journal of Science274, 321–355.

Moore, J. G. (1959). The quartz diorite boundary line in the Western United States. Journal of Geology67, 198–210.

Nabelek, P. I., Russ-Nabelek, C. & Denison, J. R. (1992). The generation and crystallization conditions of the Proterozoic Harney Peak Leucogranite, Black Hills, South Dakota, USA: petrologic and geochemical constraints. Contributions to Mineralogy and Petrology110, 173–191.

Nash, W. P. & Wilkinson, J. F. G. (1970). Shonkin Sag laccolith, Montana 1. Mafic minerals and estimates of temperature, pressure, oxygen fugacity and silica activity. Contributions to Mineralogy and Petrology25, 241–269.

Nicholls, G. D. (1951). The Glenelg–Ratagain igneous complex. Journal of the Geological Society, London106, 309–344.

Nockolds, S. R. & Allen, R. (1956). The geochemistry of some igneous rock series—III. Geochimica et Cosmochimica Acta9, 34–77.

Osborn, E. F. (1959). Role of oxygen pressure in the crystallization and differentiation of basaltic magma. American Journal of Science257, 609–647.

Patiño Douce, A. E. & Beard, J. S. (1996). Effects of P, f(O2) and Mg/Fe ratio on dehydration melting of model metagreywackes. Journal of Petrology37, 999–1024.

Patiño Douce, A. E. & Harris, N. (1998). Experimental constraints on Himalayan anatexis. Journal of Petrology39, 689–710.

Peacock, M. A. (1931). Classification of igneous rock series. Journal of Geology39, 54–67.

Pearce, J. A., Harris, N. B. W. & Tindle, A. G. (1984). Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology25, 956–983.

Petro, W. L., Vogel, T. A. & Wilband, J. T. (1979). Major-element chemistry of plutonic rock suites from compressional and extensional plate boundaries. Chemical Geology26, 217–235.

Salonsaari, P. T. & Haapala, I. (1994). The Jaala-Iitti Rapakivi complex. An example of bimodal magmatism and hydridization in the Wiborg Rapakivi batholith, southeastern Finland. Mineralogy and Petrology50, 21–34.

Sawaka, W. N., Chappell, B. W. & Kistler, R. W. (1990). Granitoid compositional zoning by side-wall boundary layer differentiation: evidence from the Palisade Crest Intrusive suite, Central Sierra Nevada, California. Journal of Petrology31, 519–553.

Scoates, J. S. S., Frost, C. D., Mitchell, J. N., Lindsley, D. H. & Frost, B. R. (1996). Residual liquid origin for a monzonitic intrusion in a Mid-Proterozoic anorthosite complex: the Sybille intrusion, Laramie anorthosite complex, Wyoming. Geological Society of America Bulletin108, 1357–1371.

Searle, M. P., Parrish, R. R., Hodges, K. V., Hurford, A., Ayres, M. W. & Whitehorse, M. J. (1997). Shisha Pangma leucogranite, south Tibetan Himalaya: field relations, geochemistry, age, origin, and emplacement. Journal of Geology105, 295–307.

Shand, S. J. (1943). The Eruptive Rocks, 2nd edn. New York: John Wiley, 444 pp.

Sheraton, J. W., Black, L. P. & Tindle, A. G. (1992). Petrogenesis of plutonic rocks in a Proterozoic granulite facies terrane; the Bunger Hills, East Antarctica. Chemical Geology97, 163–198.

Shimura, T., Komatsu, M. & Iiyama, J. T. (1992). Genesis of the lower crustal garnet–orthopyroxene tonalites (S-type) of the Hidaka metamorphic belt, northern Japan. Transactions of the Royal Society of Edinburgh: Earth Sciences83, 259–268.

Shuster, R. D. & Bickford, M. E. (1985). Chemical and isotopic evidence for the petrogenesis of the northeastern Idaho batholith. Journal of Geology93, 727–742.

Smith, D. R., Noblett, J., Wobus, R. A., Unruh, D., Douglass, J., Beane, R., Davis, C., Goldman, S., Kay, G., Gustavson, B., Saltoun, B. & Stewart, J. (1999). Petrology and geochemistry of late-stage intrusions of the A-type, mid-Proterozoic Pikes Peak batholith (Central Colorado, USA): implications for petrogenesis models. Precambrian Research98, 271–305.

Streckeisen, A. (1967). Classification and nomenclature of igneous rocks. Final report of an inquiry. Neues Jahrbuch für Mineralogie, Abhandlungen107, 144–204.

Strong, D. F. & Hamner, S. K. (1981). The leucogranites of southern Brittany: origin by faulting, frictionalshearing, fluid flux, and fractional melting. Canadian Mineralogist19, 163–176.

Sweetman, T. M. (1987). The geochemistry of the Blackstairs unit of the Leister Granite, Ireland. Journal of the Geological Society, London144, 971–984.

Tate, M. C., Norman, M. D., Johnson, S. E., Fanning, C. M. & Anderson, J. L. (1999). Generation of tonalite and trondhjemite by subvolcanic fractionation and partial melting in the Zarza intrusive complex, western Peninsular Ranges Batholith, northwestern Mexico. Journal of Petrology40, 983–1010.

Tepper, J. H., Nelson, B. K., Bergantz, G. W. & Irving, A. J. (1993). Petrology of the Chilliwack batholith, North Cascades, Washington, generation of calc-alkaline granitoids by melting of mafic lower crust with variable water fugacity. Contributions to Mineralogy and Petrology113, 333–351.

Turner, S., Arnaud, N., Liu, J., Rogers, N., Hawkesworth, C., Harris, N., Kelley, S., Van Calsteren, P. & Deng, W. (1996). Post-collisional, shonshonitic volcanism on the Tibetan plateau: implications for convective thinning of the lithosphere and the source of ocean island basalts. Journal of Petrology37, 35–71.

Valiquette, G. & Archambault, G. (1970). Les gabbros et les syenites du complexe de Brome. Canadian Mineralogist10, 485–510.

Viljoen, M. J. & Viljoen, R. P. (1969). The geochemical evolution of the granitic rocks of the Barberton region. Geological Society of South Africa, Special Publication2, 189–219.

Walawender, M. J., Gastel, R. G., Clinkenbeard, J. P., McCormick, W. V., Eastman, B. G., Wernicke, R. S., Wardlaw, M. S., Gunn, S. H. & Smith, B. M. (1990). Origin and evolution of the zoned La Posta-type plutons, eastern Peninsular Ranges batholith, southern and Baja California. In: Anderson, J. L. (ed.) The Nature and Origin of Cordilleran Magmatism. Geological Society of America, Memoir174, 1–18.

Weiss, S. & Troll, G. (1989). The Ballachulish igneous complex, Scotland: petrography, mineral chemistry, and order of crystallization in the monzodiorite–quartz diorite suite and in the granite. Journal of Petrology30, 1069–1115.

Whalen, J. B., Currie, K. L. & Chappell, B. W. (1987). A-type granites: geochemical characteristics, discrimination and petrogenesis. Contributions to Mineralogy and Petrology95, 407–418.

White, A. J. R. (1979). Sources of granite magmas. Geological Society of America, Abstracts with Programs11, 539.

White, A. J. R. & Chappell, B. W. (1983). Granitoid types and their distribution in the Lachlan Fold Belt, southeastern Australia. In: Roddick, J. A. (ed.) Circum-Pacific Plutonic Terranes. Geological Society of America, Memoir159, 21–34.

Yoder, H. S. & Tilley, C. E. (1962). Origin of basaltic magmas: an experimental study of natural and synthetic rock systems. Journal of Petrology3, 342–532.

Zen, E. (1986). Aluminum enrichment in silicate melts by fractional crystallization: some mineralogic and petrologic constraints. Journal of Petrology27, 1095–1117.

Zen, E. (1988). Phase relations of peraluminous granitic rocks and their petrogenetic implications. Annual Review of Earth and Planetary Sciences16, 21–52.

Zhao, J.-X., Shiraishi, K., Ellis, D. J. & Sheraton, J. W. (1995). Geochemical and isotopic studies of syenites from the Yamato mountains, East Antarctica: implications for the origin of syenitic magmas. Geochimica et Cosmochimica Acta59, 1363–1382.