Misery antilles lavas ave antilles ave japan lava ash

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Unformatted text preview: illes (lavas) Ave. Antilles Ave. Japan (lava, ash falls) B 9 0 17 17 14 B-A 23 78 22 A 55 4 49 42 85 D 9 18 12 39 2 After Gill (1981, Table 4.4) B = basalt B-A = basaltic andesite A = andesite, D = dacite, R = rhyolite R 4 0 0 2 0 Major Elements and Magma Series Major q q q Tholeiitic (MORB, OIT) Alkaline (OIA) Calc-Alkaline (~ restricted to SZ) Major Elements and Magma Series Magma a. Alkali vs. silica a. b. AFM c. FeO*/MgO vs. silica c. diagrams for 1946 analyses from ~ 30 island and continental arcs with emphasis on the more primitive volcanics primitive Figure 16-3. Data compiled by Terry Plank (Plank and Langmuir, 1988) Earth Planet. Sci. Lett., 90, 349-370. Sub-series of Calc-Alkaline Sub-series q K2O is an important discriminator → 3 sub-series is Figure 16-4. The three andesite series of Gill (1981) Orogenic Andesites and Plate Tectonics. Springer-Verlag. Contours represent the concentration of 2500 analyses of andesites stored in the large data file RKOC76 (Carnegie Institute of Washington). Figure 16-6. a. K2O-SiO2 diagram distinguishing high-K, medium-K and low-K series. Large squares = high-K, stars = med.-K, diamonds = low-K series from Table 16-2. Smaller symbols are identified in the caption. Differentiation within a series (presumably dominated by fractional crystallization) is indicated by the arrow. Different primary magmas (to the left) are distinguished by vertical variations in K2O at low SiO2. After Gill, 1981, Orogenic Andesites and Plate Tectonics. Springer-Verlag. Figure 16-6. b. AFM diagram distinguishing tholeiitic and calc-alkaline series. Arrows represent differentiation trends within a series. Figure 16-6. c. FeO*/MgO vs. SiO2 diagram distinguishing tholeiitic and calc-alkaline series. Figure 16-6. From Winter (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall. Figure 16-6. c. FeO*/MgO...
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