| Aquia Formation Stratigraphic range: Late Paleocene ~59.0–55.5 Ma | |
|---|---|
.jpg')) Thecachampsa crocodile coprolite (Aquia Formation; King George County, Virginia) | |
| Type | Geological formation |
| Unit of | Pamunkey Group |
| Sub-units | Paspotansa & Piscataway Members |
| Underlies | Nanjemoy Formation |
| Overlies | Brightseat Formation |
| Thickness | up to 100 feet (30 m) |
| Lithology | |
| Primary | Sandstone |
| Location | |
| Location | Hopewell, Virginia |
| Coordinates | 38°18′N 77°18′W / 38.3°N 77.3°W |
| Approximate paleocoordinates | 39°00′N 58°54′W / 39.0°N 58.9°W |
| Region | Maryland, New Jersey, Virginia |
| Country |  United States |
| Extent | Upper Chesapeake Bay-James River |
| Type section | |
| Named for | Aquia Creek |
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
- Abdounia beaugei[2][6]
- Anomotodon novus[2][7]
- Carcharias hopei[2][7]
- Cretolamna appendiculata[2][7]
- Delpitoscyllium africanum[2]
- Foumtizia abdouni[2]
- Galeorhinus[2]
- Ginglymostoma subafricanum[2]
- Heterodontus lerichei[2]
- Hypotodus verticalis[2]
- Isurolamna inflata[2]
- Megasqualus orpiensis[2]
- Notidanodon loozi[2]
- Odontaspisx loozi[2]
- Orectolobiform[2]
- Otodus obliquus[2][8][7]
- Pachygaleus lefevrei[2]
- Palaeogaleus[2]
- Paleocarcharodon orientalis[2][8][7]
- Paleohypotodus rutoti[2][9]
- Paraorthacodus clarkii[2]
- Physogaleus secundus[10]
- Premontreia subulidens[2]
- Scyliorhinus[2]
- Squalus
- Squatina prima[2]
- Striatolamia macrota[2][7]
- Striatolamia striata[2]
- Triakis[2]
Rays
- Myliobatis[11]
- Burnhamia[2]
- Coupatezia soutersi[2]
- Dasyatis[2]
- Hypolophodon sylvestris[2]
- Ischyodusx sylvestris[2]
Reptiles
Crocodylians
Turtles
Mammals
Mammal fossils are extremely rare.[2]
Birds
Bird fossils are extremely rare.[2]
Molluscs
Gastropods
- Turritella is very common.[2][7][14]
- Pleurotoma potomacensis[15]
Bivalves
- Crassatelites alaeformis[15]
- Cucullaea gigantea[16][15][17]
- Dosiniopsis lenticularis[15]
- Meretrix ovata[15]
- Modiolus alabamensis[15]
- Ostrea compressirostra[18][15]
- Panopea elongata[15]
- Venericardia planicosta[15]
- Volsella alabamensis[18]
Cephalopods
- Cimomia marylandensis is present but uncommon.[19]
See also
- List of fossiliferous stratigraphic units in Virginia
- Paleontology in Virginia
- Aquia Creek sandstone
- Public Quarry at Government Island
References
- ^ 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.
- ^ 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
- ^ a b "Coastal Plain Rocks and Sediments". Geological Maps of Maryland. Maryland Geological Survey. 1968. Retrieved 21 January 2015.
- ^ 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.
- ^ Page, Richard A (1959). "The Questionable Age of the Aquia Formation". Journal of Paleontology. 33 (2): 347–350. JSTOR 1300764.
- ^ http://www.elasmo.com/frameMe.html?file=genera/cenozoic/sharks/abdounia.html&menu=bin/menu_genera-alt.html
- ^ a b c d e f g h i j k http://www.fossilguy.com/sites/potomac/liv_col.htm
- ^ a b http://www.thefossilforum.com/index.php?/topic/82854-potomac-aquia-formation-31518/
- ^ http://www.thefossilforum.com/index.php?/topic/83055-paleohypotodus/
- ^ http://www.itano.net/fossils/marylan2/galeo1s.htm
- ^ http://www.itano.net/fossils/marylan2/mylio1s.htm
- ^ http://www.itano.net/fossils/marylan2/theca1s.htm
- ^ http://www.itano.net/fossils/marylan2/trion1s.htm
- ^ http://www.itano.net/fossils/marylan2/turr1s.htm
- ^ a b c d e f g h i Virginia Division of Mineral Resources (1912). Bulletin. p. 200.
fossils of the aquia formation.
- ^ https://iapetancaptain.wordpress.com/2010/05/15/cucullaea-gigantea/
- ^ http://viewsofthemahantango.blogspot.com/2014/08/cucullaea-gigantea-pelecypod-from-aquia.html
- ^ a b http://www.itano.net/fossils/marylan2/ostre1s.htm
- ^ http://www.thefossilforum.com/index.php?/topic/84977-sanity-check-its-a-nautilus-right/