The Brightseat Formation is an exposure of marine sedimentary rock beds of Upper Cretaceous/Lower Paleocene age (65 MY to 55.5 MY), in Landover, Maryland. The exposure is located at Brightseat Road between Sheriff and Landover Roads. The site is currently owned by the Maryland-National Capital Park and Planning Commission. It was given its name by R.R. Bennett and G.G. Collins in 1952.[1]

According to the Maryland Geologic Survey, the exposure consists of "Gray to greenish-gray, micaceous, argillaceous, sparsely glauconitic, fine- to coarse-grained sand, locally indurated calcareous beds; phosphatic pebbles; thickness 0 to 20 feet."[2]

Research

Available research on the flora and fauna of the Brightseat Formation is decades-old. In 1968, thirty-five species of minute crustaceans, ostracodes, mostly cytheraceans, were found at outcrops of the Brightseat Formation, including 13 new species.[3] The presence of otoliths, calcareous secretions that accumulate within the auditory chambers of bony fish, indicate the presence of fish fauna in the formation.[4] The Brightseat Formation has also yielded three taxa of sea turtles: Taphrosphys sulfates (Leidy), Agomphus sp., and Osteopygis emarginatus Cope.[5]

References

  1. ↑ Bennett, R.R., and Collins, G.G., 1952, Brightseat Formation, a new name for sediments of Paleocene age in Maryland: Journal of the Washington Academy of Sciences, v. 42, no. 4, p. 114–116.
  2. ↑ Maryland Geological Survey - Coastal Plain Rocks and Sediments 1968
  3. ↑ Journal of Paleontology v. 42 no. 1 p 100–142 January 1968
  4. ↑ Travisono, Jeanne. 1981. AAPG Bulletin Volume 65 p 656
  5. ↑ Weems, R. E. 1988. Paleocene turtles from the Aquia and Brightseat formations, with a discussion of their bearing on sea turtle evolution and phylogeny. Proceedings of the Biological Society of Washington 101:109–145.
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