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Time differences within a calc-alkaline association
Contributions to Mineralogy and Petrology, 1972A Strontium isotope study of a high-K diorite complex at Yeoval, N.S.W. (Australia) points to clear time differences (40 m.y.) between the diorite suite (gabbro-diorite-grano-diorite) and surrounding granites. Such a time interval, in association with other data, precludes a genetic relationship between these rock groups whereas the data support a ...
Gulson, B. L., Bofinger, V. M.
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Origin of Lead in Andean Calc-Alkaline Lavas, Southern Peru
Science, 1980Lead isotope data from Quaternary andesitic lavas of the Arequipa and Barroso groups of southern Peru and from regional Precambrian granulitic gneisses reveal a lead component in the lavas from the gneisses. The lava leads can be accounted for by two-component mixtures of lead from mantle and lower crustal sources, although the mixing process need not ...
G R, Tilton, B A, Barreiro
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Physicochemical model for the crystallization of rocks of the calc-alkaline series
Geochemistry International, 2012The Al-rich region of the CaO-MgO-Al2O3-SiO2 system was experimentally studied at pressures of 1.0–2.8 GPa and temperatures of 1300–1535°C. The slopes of the lines of the monovariant reactions An + Sp = Cpx + Cor + (Ga) and L = Cpx + Ga + Cor + Sp and the compositions of the phases involved in these reactions are determined. The results are utilized in
N. V. Surkov, Yu. G. Gartvich
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Radioactivity and geochemistry of calc-alkaline neovolcanites of the West Carpathians
Studia Geophysica et Geodaetica, 1989The distribution of radioactive elements(Th, U, K) and selected trace elements(Rb, Sr, Ba, Y, Zr, V, Cr, Ni) in a set of 29 volcanic rocks of the West Carpathians was studied. The rock types follow the typical calc-alkaline sequence from basaltic andesites to rhyolites with average contents of SiO2, K2O, Th, U, Rb, Ba and Zr increasing, and with ...
Vladimír Kropáček, Věra Vaňková
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Calc-alkaline nuees ardentes: A new classification
Journal of Geodynamics, 1985Several nuees ardentes deposits, all in a subduction context (Lesser Antilles, Central America, Washington-U.S.A., Kamchatka, Indonesia) are compared. All these tephra are andesitic to dacitic and have a typical calc-alkaline minerology. A new classification is proposed on the basis of glass-grain morphology and grain-size analyses of the deposits.
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Vesiculation processes in a water-rich calc-alkaline obsidian
Earth and Planetary Science Letters, 1997The effect of temperature and viscosity on the kinetics of bubble growth was measured for a natural water-rich rhyolite melt. The change in volume of a natural crystal-poor calc-alkaline rhyolitic obsidian with an initial water content of ≈ 1.8 wt% H2O was determined in the temperature interval 520–624°C.
STEVENSON R. J +2 more
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Effects of volatiles on mixing in calc-alkaline magma systems
Nature, 1982The intimate mixing between different magmas of disparate densities, characteristic of some calc-alkaline magma systems, is explained by a new mechanism involving the emplacement of a layer of wet undersaturated mafic magma at the base of a magma chamber containing more differentiated magma.
Herbert E. Huppert +2 more
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Chlorine from seawater is key to the generation of calc-alkaline lavas
Journal of Asian Earth Sciences, 2021Abstract Most primary magmas evolve compositionally as either tholeiitic or calc-alkaline lava series. The most voluminous magmas are generated through decompression melting of the upper mantle beneath diverging tectonic plates and differentiate as tholeiitic lavas. Calc-alkaline lavas, on the other hand, consist mainly of the bulk of differentiating
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Petrography and geochemistry of Plio-Quaternary calc-alkaline volcanoes of Southwestern Colombia
Journal of South American Earth Sciences, 1996Abstract The six studied southwestern Colombian Plio-Quaternary volcanoes (Purace, Dona Juana, Galeras, Azufral, Cumbal and Chiles) are located in the central part of the Northern Volcanic Zone (NVZ) of the Andes. The lavas are predominantly andesites and dacites, with lesser amount of basalt, and range 52% to 70% SiO2.
Delaloye, Michel, Droux, Alain
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Calc‐alkaline magmatism, lithospheric thinning and extension in the Basin and Range
Journal of Geophysical Research: Solid Earth, 1995Most of the volcanic rocks in the Colorado River Trough (CRT) and the Mogollon‐Datil Volcanic Field (MDVF) in the Basin and Range exhibit calc‐alkaline major element trends and relatively low high field strength element abundances, similar to those erupted from the volcanoes of Aso and Towada in Japan.
Chris Hawkesworth +5 more
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