Karl August Lossen

Karl August Lossen (born Kreuznach (Rhineland), 5 January 1841; died Berlin, 24 February 1893) was a German petrologist and geologist.

In 1873, he was made a member of the newly founded Prussian National Geological Institute, and in 1882 received the title of professor; he was a fellow of the Görres Society from its foundation.

He published the results of his investigation in over one hundred treatises and notices which appeared for the most part in the Zeitschrift der deutschen geologischen Gesellschaft of 1867–1891.

The work of his youth, De Tauni montis parte transrhenana (Halle, 1867), appeared independently; then in 1877 followed the maps of the geological survey of the Harz Mountains and later many special maps of the Harz district, and the exhaustive work, Boden der Stadt Berlin (The Terrain of Berlin).

He was considered as an authority on this subject, such that the committee in charge of the programme for the International Geological Congress in London requested him to present a paper on the origin of crystallized slate (printed in 1888).