Calvert Cliffs State Park is a
state park in Calvert County, Maryland, situated on
the Chesapeake Bay. On the 1612 John Smith map, the
site was called Rickard's Cliffes. The park is
located in Lusby, Maryland.
It is a short distance south
of Calvert Cliffs Nuclear Power Plant operated by
Geology and paleontology
The park is known for the abundance of mainly Middle
Miocene sub-epoch fossils, which can be found on the
shoreline. It contains the type locality site of the
Early to Middle Miocene Calvert Formation. These
rocks are the sediment from a coastal ocean that
covered the area during that time.
The age of the formation is
(19-)18-15 (-14) million years, i.e. it extends
essentially over the Hemingfordian stage. This
formation occurs in Maryland and neighboring
In addition, rocks of the
younger Choptank and the St. Marys Formations are
exposed. This makes Calvert Cliffs State Park highly
interesting for paleoclimatology and paleontology,
because the accessible strata provide a good record
of the Middle Miocene Climate Transition and
documents a minor mass extinction event, the Middle
The Calvert Formation is also
notable for the plentiful fossil shark teeth found
therein. Especially popular among "rockhounds"
are those from giants such as Carcharocles
and the famous Megalodon (which is often
included in Carcharocles).
Some remains of a prehistoric
loon (Gavia) are also believed to be from the
Calvert Formation; they are the oldest record of
that genus known from North America. Collecting can
be done on the beach as access to the Cliffs is no
longer available due to erosion.
The ancestral baleen whale Eobalaenoptera
harrisoni and the merganser Mergus miscellus
were described from the Virginian part of the
formation. From the uppermost layer, deposited 15-14
million years ago, they represent the oldest known
member of their family and genus, respectively.
Fishing, hiking trails, historic interest, hunting,
picnicking, youth group camping, playground,