CUCKOLD CREEK

THIS LOCATION IS ON PRIVATE PROPERTY AND IS INACCESSIBLE TO THE PUBLIC

GEOLOGY

MARYLAND U.S.A

 

The area is located in the Inner Coastal Plain physiographic province which slopes gently to the east, the deposits form a wedge of unconsolidated sediments like carbonates including sand, gravel and silt which expand all the way out into the Atlantic Ocean.

 

The sediment of the Atlantic Coastal plain sits on top of the Eastern Piedmont, the change over is visible at the Fall Line where the Piedmont zone dips below and the Coastal Plain starts. The Piedmont is comprised of crystalline metamorphic and igneous rocks which sit between the Blue Ridge further to the west and the Atlantic Coastal Plain further East.   

 

The Atlantic Coastal Plain thickens from 0 (Contact with the Piedmont zone) to 8,000 feet moving towards the Atlantic Ocean, 45 miles out to sea is where the Atlantic Coastal Plain expands to a maximum depth of 40,000 feet at the contact with the Atlantic Continental Shelf Province which is even further offshore.  

  

ROCK LAYERS

An outcrop of the Choptank Formation is evident on geologic maps close by, this formation is apart of the Chesapeake Group and was deposited during the Miocene age (23 to 5 million years ago). The formation is a mix of interbedded brown and yellow fine-grained sand and grey to dark blueish-green silt containing a mix of clay. Hardened calcareous sandstone and prominent shell beds are also visible in the 50-foot (15 meter) high formation. 

 

LOWLAND DEPOSITS

The steep slopes visible in this location were deposited during the Pleistocene and range from 0 to 150 feet (0 to 45 meters) in height. The 'formations' lithology visible at this location is a mix of medium-to coarse-grained gravel and sand, silt, reworked Eocene glauconite and calcareous sandstone. The lower layers that aren't visible also contain conglomerate. The sediment was most likely deposited in a river, delta, and shallow sea environments.

FOSSIL SHELLS

Shell Fossils found at Cuckold Creek:

Pecten (Chlamys) Madisonius

Pecten (Chlamys) Madisonius scallops are apart of the Chesapecten genus and apart of the benthic shallow marine community, they were most likely low-level epifaunal suspension feeders. Shells from the Chesapecten species are fan-shaped with dorsal auricles and ribs visible on the top and bottom of the shell, adults range from 16cm,10cm and to 5cm in length but this is dependent on type and species within the genus.

The genus Chesapecten went extinct in the Pliocene-Pleistocene, this extinction is linked to a change in oceanic conditions, lack of food diversity and the separation of the Atlantic and Pacific oceans. 

 

The species Pecten (Chlamys) Madisonius were once visible in the waters of Maryland and surrounding states through the Miocene and Pliocene period and range from 15 to 2 million years in age and went extinct before the rest of the genus.  

REFEreNCES

Glaser, J. D. & Baltimore: Maryland Geological Survey. (1971). Geologic Map of Southern Maryland | Geology and Mineral Resources of Southern Maryland. Johns Hopkins Sheridan Libraries. 

Maryland Geological Survey. (n.d.). Miocene Fossils | Figure No. 15.

Judith Anne Sclafani. (2011). A Morphological and Phylogenetic Examination of the Miocene and Pliocene Bivalve Genus Chesapecten. W&M ScholarWorks (William and Mary University). 

United States Geological Survey (USGS). (n.d.). Mineral Resources, Chesapeake Group: Choptank Formation. Retrieved October 30, 2020.

Maryland Geologic Survey. (n.d.). Maryland Geology | Atlantic Coastal Plain & Piedmont. 

Maryland Geological Survey & Army Map Service Sheets. (1968). Geologic Maps of Maryland: St. Marys County. Geologic Maps of Maryland. 

Maryland Geological Survey. (n.d.-a). Geologic Maps of Maryland (1968): Coastal Plain Rocks and Sediments. Maryland Geological Survey, Geologic Maps Legends. Retrieved 1968, from 

United States Geological Survey (USGS). (n.d.). Mineral Resources, Lowland Deposits. Retrieved October 30, 2020.

Atlantic Coastal Plain physiographic provinces. (2016, December 13). United States Geological Survey (USGS).

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NEW MEXICO, U.S.A
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MARYLAND, U.S.A