Janos Pettko

* Drétoma, November 11, 1812 – † Bratislava, October 20, 1890 / geologist, imperial and royal mining advisor, corresponding member of the Hungarian Academy of Sciences ; ; His father, Dániel Pettkó, was a landowner and county judge. He studied at the Lutheran high school in Győr and Bratislava. Since his father intended him to be a priest, he also studied theology for two years, but later he became an apprentice with the Trenčín County Viceroy and in the meantime he learned Hungarian, German and French and also gained expertise in law. He took his law exams in Prešov. At the age of 24 he became a student at the Mining and Forestry Academy in Selmecbánya and, in addition to his mining and geological skills, he also mastered the English language. He apprenticed at the smelter in Körmöcbánya, and then in Vienna he attended mineralogy lectures with Wilhelm Haidinger. He also made a study trip of a few months in Saxony and the Harz Mountains, and then became an assistant professor of the department of mineralogy and geology in Selmecbánya. In addition to his teaching work, he prepared the geological map of Selmecbánya and its surroundings, as well as the geohistorical age determination of the layers here. In 1848, in Videfalva, at the house of Ágoston Kubinyi, he was also there when some people decided to found the Hungarian Geological Society. In 1852, he carried out a geological investigation along the left bank of the Morva River on behalf of the Society and the Society reported on this in the first volume of the Society's Works, published in 1856. The Hungarian Academy of Sciences elected him a corresponding member in 1861. After his retirement, from the 1860s onwards, his eyesight deteriorated and he was less and less able to perform his teaching work. In 1871, he moved to his daughter's family and lived in Bazin and then in Bratislava. János Pettkó is considered the founder of Hungarian geology, and he initiated such outstanding geologists as József Szabó, Miksa Hantken, Vilmos Zsigmondy, János Böckh, Elek Pávai-Vajna, Benő Winkler, Sándor Gesell and the Beckó-born Dionýz Štúr (1827–1893). He published numerous cartographic, meteorological, geological and paleontological studies in German and Hungarian in the professional journals of the time. ; ; His main works: ; Geologische Karte der Gegend von Schemnitz, 1853, ; A geológiai jégkorszakról (academic chair collection), 1863, ; Die jüngste Controverse über die Theorie der Eiszeit, 1865.