It is the earliest unit in the marine - transgressive sedimentary rock sequence deposited during the early Paleozoic as sea level rose to gradually inundate the craton of the paleocontinent of Laurentia .
The Potsdam Sandstone lies unconformably on a surface of Precambrian metamorphic rock .
Potsdam Sandstone is the earliest unit in the marine - transgressive sedimentary rock sequence deposited during the early Paleozoic as sea level rose to gradually inundate the craton of the paleocontinent of Laurentia .
The Potsdam Sandstone lies unconformably on a surface of Precambrian metamorphic rock .