Atzgersdorf Stone, in earlier times an important type of stone used in construction in Vienna (e.g. Karlskirche church), deposited in a peripheral area of the Vienna Basin Sea in the late Tertiary period (Sarmatian Stage) approximately 6 million years ago.
Further reading#H. Kuepper, Vienna, 1968 (ed.: Geologische Bundesanstalt Wien); F. Brix, Naturgeschichte Wiens, 1970-74.