ROSENBUSCH, KARL HARRY FERDINAND

ROSENBUSCH, KARL HARRY FERDINAND (1836–1914), German geologist. Rosenbusch, who was born at Einbeck, was appointed professor of petrography at Strasbourg University in 1873 and in 1878 became professor of mineralogy and geology at Heidelberg, where he spent the rest of his life. From the 1870s, when he began to publish important works on the subject, until his death, he was one of the great pioneers of petrographic research, and these years were often referred to in the profession as the "Rosenbusch period." His Mikroskopische Physiographic der petrographisch wichtigen Mineralen (1873; with E. Wuefling, 19044) identified rocks by studying the morphological, physical and chemical properties of their mineral components. It became a standard textbook on the microscopic investigation of rocks for many generations of students and scholars. No less important was his Mikroskopische Physiographie der massigen Gesteine (1877, 1896), which made a fundamental contribution to the development of systematic petrography. Combining microscopic and chemical research with field observations, this book gave a strong impulse to the discussion of genetic problems and the passive or active behavior of the magma in mountain building. Rosenbusch's most widely-used textbook was Elemente der Gesteinslehre (1898), which laid great emphasis on rock-chemistry and on the geodynamic processes in the formation of crystalline schists. In this field, he had made a classic contribution as early as 1877 through his study, Steiger Schriefer und ihre Kontakt-Zone an den Graniten von Barr-Andlau und Hohwald. (Leo Picard)