Ebook: A new cation plot for classifying subalkalic volcanic rocks

Ontario: Ministry of Natural Resources, 1976. — 22 p.Диаграмма AFM Дженсена (в катионных процентах) для разделения магматитов на известково-щелочную, толеитовую и коматиитовую генетические серии. Первая публикация.A new cation plot (Jensen Cation Plot) is proposed as an alternative method for classifying subalkalic volcanic rocks. It is a ternary plot relating the cation percentages of Al2O3, FeO + Fe2o3 + TiO2 , and MgO. On this plot, it is possible to recognize and discriminate between differentiation trends of komatiitic, tholeiitic, and calc-alkalic suites of volcanic rocks, encompassing such types as peridotitic and basaltic komatiite, magnesium-rich and iron-rich tholeiitic basalt, tholeiitic andesite, tholeiitic dacite, and tholeiitic rhyolite, and calc-alkalic basalt, calc-alkalic andesite, calc-alkalic dacite, and calc-alkalic rhyolite. A relative rock colour that approximates the original fresh rock
surface is provided with each plot to facilitate correlation in the field. Six separate suites of volcanic rocks from around the world, plus a detailed volcanic sequence of Early Precambrian (Archean) rocks are used to illustrate the use of the Jensen Cation Plot and to show the deficiency of more widely used volcanic rock classifications, in particular, those involving the AFM diagram.Распознанный pdf-файл.