potsdam-group
Pots"dam group` (. (Geol.) Defn: A subdivision of the Primordial or Cambrian period in American geology; -- so named from the sandstone of Potsdam, New York. See Chart of Geology.
Pots"dam group` (. (Geol.) Defn: A subdivision of the Primordial or Cambrian period in American geology; -- so named from the sandstone of Potsdam, New York. See Chart of Geology.