1719-1767

German Geologist

Johann Gottlob Lehmann established the foundations of stratigraphy, or the scientific study of sedimentary rocks with regard to their order and sequence. His Versuche einer Geschichte von Flotz-Gebrugen (1756), in which he classified mountains and established a theory of their origins, was the world's first geologic profile.

Lehmann was born on August 4, 1719, in Langenhennersdorf, then in the state of Saxony but now a part of Germany. He earned his M.D. at the University of Wittenberg in 1741, and went on to a medical practice in the city of Dresden. While working as a doctor, however, he discovered something that interested him more than medicine: rocks.

His amateur fascination with mines and mining soon turned into a vocation, and by 1750 the 31-year-old Lehmann had published a number of papers on ore deposits and their chemical makeup. These publications helped lead to an official...