Evolution of calc-alkaline to alkaline magmatism through Carboniferous convergence to Permian transcurrent tectonics, western Chinese Tianshan

High-Mg# andesitic lavas of the Shisheisky Complex, Northern Kamchatka: implications for primitive calc-alkaline magmatism

Primitive arc magmatism and mantle wedge processes are investigated through a petrologic and geochemical study of high-Mg# (Mg/Mg ? Fe [ 0.65) basalts, basaltic andesites and andesites from the Kurile-Kamchatka subduction system. Primitive andesitic samples are from the Shisheisky Complex, a field of Quaternary-age, monogenetic cones located in the Aleutian–Kamchatka junction, north of Shiveluc...

Transition from Paleogene Normal Calc-Alkaline to Neogene Adakitic-Like Plutonism and

Significance of hornblende in calc-alkaline andesites and basalts

Hornblende occurs in some andesitic and basaltic rocks of calc-alkaline affini1y, where it is commonly associated with olivine. The texture, eruption history, and composition are interpreted to indicate that hornblende commonly forms as a product of reaction between olivine and basaltic and andesitic liquids. The natural hornblendes probably formed within the crust at temperatures between 960o ...

transition from paleogene normal calc-alkaline to neogene adakitic-like plutonism and

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K-T magmatism and basin tectonism in western Rajasthan, India, results from extensional tectonics and not from Reunion plume activity

Evolution of sedimentary basins took place in the Barmer, Jaisalmer and Bikaner regions during K-T (Cretaceous-Tertiary) time in western Rajasthan, India. These intra-cratonic rift basins developed under an extensional tectonic regime from early Jurassic to Tertiary time. Rift evolution resulted in alkaline magmatism at the rift margins. This magmatism is dated at 68.5 Ma and has been considere...