D defs.my
Entry 1 sense Webster, 1913

Potsdam group

/pät'-sdămˌ gro͞op/ · Pots·dam group · IPA
01 A subdivision of the Primordial or Cambrian period in American geology; -- so named from the sandstone of Potsdam, New York. See Chart of G…
  1. 1.
    A subdivision of the Primordial or Cambrian period in American geology; -- so named from the sandstone of Potsdam, New York. See Chart of Geology.(Geol.) See: Geology