Rough map of Calvert County, with collecting sites, and exposed formations along the beach.
St. Mary's Formation is roughly 8 - 12 million years old
Choptank Formation is roughly 12 - 18 million years old
Calvert Formation is roughly 18 - 22 million years old
Each Formation is layered on top of the other, with the youngest on top. However, these
Miocene deposits are slightly tilted,
gradually dipping toward the ground as one moves
south, approximately 10 feet per mile (Gernant,1970,p.6). This results in the
Calvert Formation going completely underground around Scientists
Cliffs, and the Choptank Formation going underground near Cove Point. Basically, what
this means is the further south one goes, the younger the
deposits get (almost like a time machine), as shown on the map.
Please Note, I made this very simplified map based on an old dusty geologic map of Calvery county from the
Maryland Geologic Survey.
This map is no substitute for a real geologic map or a road map.