His earlier work comprised a monograph on the Cretaceous bivalve mollusca of Gosau (1863–66); and an essay on the Tithonian stage (1870), regarded as equivalent to the Purbeck and Wealden formations.
To the south the border runs from Lake Hallstatt up the Gosau Valley to Gschütt Pass, and from there downhill along the Rußbach Valley, separating the Salzkammergut Mountains from the Tennengebirge in the southwest, and the Lammer creek to its confluence with the Salzach near Golling.