LOEWINSON-LESSING, FRANZ YULYEVICH

LOEWINSON-LESSING, FRANZ YULYEVICH (1861–1939), Russian geologist, pioneer of magmatic petrology. Loewinson-Lessing occupied the chair of geology, petrology, and mineralogy first at the University of Dorpat (now Tartu), Estonia, and from 1902 until his retirement in 1930, at the Polytechnic Institute of St. Petersburg (Leningrad). In 1925 he was elected a member of the Soviet Academy of Sciences, where he was appointed director of the newly established Petrographical Institute. As early as 1897, in a paper presented to the international geological congress held in St. Petersburg, Loewinson-Lessing introduced a chemical classification of igneous rocks. This was followed by shorter papers on petrochemistry, in which he discussed the role of assimilation in the origin of magmatic rocks and applied the "phase rule" of physical chemistry to substantiate his synthetic-liquational theory of differentiation. In his later years he also dealt with the physical properties of rocks and the tectonic movements of igneous masses. The two books on petrography which he published in 1923, Uspekhi petrografii v Rossii ("Advances in Petrography in Russia") and Voedeniye v geologiyu ("Introduction to Geology"), became standard textbooks in the U.S.S.R.

bibliography:

P.I. Lebedev, Akademik P. Yu. Loewinson-Lessing kak teoretik petrografii (1947); A.A. Zvorykin (ed.), Biograficheskiy slovar deyateley yestestvoznaniya i tekhniki, 1 (1958), 502–3.

[Leo Picard]