Joseph Paxson IddingsBorn 21 Jan 1857; died 8 Sep 1920 at age 63.American geologist who advanced understanding in the field of petrology - the study of the origin, composition, structure, and alteration of rocks. Around 1880, he was one of the first in the U.S. to study thin rock sections with a microscope. He explored and mapped the geology of Yellowstone National Park during seven field seasons (1883-1890). From this study he introduced original ideas concerning the range of crystal line textures and mineral composition of granular igneous rocks. He proposed that physical and chemical conditions causing differences in the formationof neighbouring igneous rock from the same igneous magma. Further, he rejected the prevailing view that granular rocks were only formed in large masses at depth.« |
