docalcic

Century Dictionary and Cyclopedia

1. In petrography, dominantly calcic: used in the quantitative classification of igneous rocks (see rock) to describe divisions of igneous rock-magmas characterized by a dominance of calcium oxid over contrasted constituents. In Classes I, II, III, docalcic rangs are those in which lime preponderates over potash and soda, in the salic constituents within the ratio . In Classes IV, V, docalcic sections of rangs are those in which lime preponderates over magnesia and ferrous iron in the femic constituents within the limits .