Aquia Formation

The Aquia Formation is a geologic sandstone formation that extends from the upper Chesapeake Bay to the James River near Hopewell, Virginia.[1] It consists of clayey, silty, very shelly, glauconitic sand.[1] Fossil records indicate that this stratigraphic unit was created during the Paleocene.[1]

The Aquia formation was named for Aquia Creek where it is exposed in cliff faces along the banks.[2]

Geology

Lithology

When uncovered, it appears dark green to gray-green, argillaceous, with well sorted fine- to medium-grained sand and locally indurated shell beds.[3] It occurs between 0 and 100 feet thick.[3] Quartz and phosphatic pebbles and/or very coarse glauconitic quartz sand mark the base of the unit.[4] A few hard streaks of shells or thin "rock" layers are often reported but appear to be more abundant in the sections south of the James River.[4]

Stratigraphy

The Aquia formation is overlain by the Nanjemoy Formation and overlies the Brightseat Formation.[5]

The Aquia formation is broken down into two members: the lower Piscataway member and upper Paspotansa member.[2]

Age

The Aquia Formation is thought to be 59.0-55.5 million years old.[2] The Piscataway member is 59-56.25 million years old, and the Paspotansa member is 56-55.5 million years old.[2]

Fossils

Vertebrates

Bony fish

Chondrichthyes

Sharks
Rays

Reptiles

Crocodylians
Turtles

Mammals

Mammal fossils are extremely rare.[2]

Birds

Bird fossils are extremely rare.[2]

Molluscs

Gastropods

Bivalves

Cephalopods

  • Cimomia marylandensis is present but uncommon.[19]

See also

References

  1. ^ a b c Geology of the National Capital Region - Field Trip Guidebook. Reston, Virginia: U.S. Geological Survey, Department of the Interior. 2004. p. 270.
  2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar http://phatfossils.com/Aquia%20Formation%20Paleocene%20of%20Maryland%20and%20Virginia.php
  3. ^ a b "Coastal Plain Rocks and Sediments". Geological Maps of Maryland. Maryland Geological Survey. 1968. Retrieved 21 January 2015.
  4. ^ a b Powars, D.S.; Bruce, T.S. (2000). The Effects Of The Chesapeake Bay Impact Crater On The Geological Framework And Correlation Of Hydrogeologic Units Of The Lower York-James Peninsula, Virginia. United States Geological Survey. Retrieved 22 January 2015.
  5. ^ Page, Richard A (1959). "The Questionable Age of the Aquia Formation". Journal of Paleontology. 33 (2): 347–350. JSTOR 1300764.
  6. ^ http://www.elasmo.com/frameMe.html?file=genera/cenozoic/sharks/abdounia.html&menu=bin/menu_genera-alt.html
  7. ^ a b c d e f g h i j k http://www.fossilguy.com/sites/potomac/liv_col.htm
  8. ^ a b http://www.thefossilforum.com/index.php?/topic/82854-potomac-aquia-formation-31518/
  9. ^ http://www.thefossilforum.com/index.php?/topic/83055-paleohypotodus/
  10. ^ http://www.itano.net/fossils/marylan2/galeo1s.htm
  11. ^ http://www.itano.net/fossils/marylan2/mylio1s.htm
  12. ^ http://www.itano.net/fossils/marylan2/theca1s.htm
  13. ^ http://www.itano.net/fossils/marylan2/trion1s.htm
  14. ^ http://www.itano.net/fossils/marylan2/turr1s.htm
  15. ^ a b c d e f g h i Virginia Division of Mineral Resources (1912). "Bulletin".
  16. ^ https://iapetancaptain.wordpress.com/2010/05/15/cucullaea-gigantea/
  17. ^ http://viewsofthemahantango.blogspot.com/2014/08/cucullaea-gigantea-pelecypod-from-aquia.html
  18. ^ a b http://www.itano.net/fossils/marylan2/ostre1s.htm
  19. ^ http://www.thefossilforum.com/index.php?/topic/84977-sanity-check-its-a-nautilus-right/

This page was last updated at 2019-11-11 08:54 UTC. Update now. View original page.

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