Aquia Formation

Aquia Formation
Stratigraphic range: Late Paleocene
~
Boulder of Aquia Formation along Chester River. Contains casts of large mollusks. (c. 1917)
TypeGeological formation
Unit ofPamunkey Group
Sub-unitsPaspotansa & Piscataway Members
UnderliesNanjemoy Formation
OverliesBrightseat Formation
Thicknessup to 100 feet (30 m)
Lithology
PrimarySandstone
Location
LocationHopewell, Virginia
Coordinates38°18′N 77°18′W / 38.3°N 77.3°W / 38.3; -77.3
Approximate paleocoordinates39°00′N 58°54′W / 39.0°N 58.9°W / 39.0; -58.9
RegionMaryland, New Jersey, Virginia
CountryUnited States
ExtentUpper Chesapeake Bay-James River
Type section
Named forAquia 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 is between 0 and 100 feet thick in Maryland.[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] This is the Paleocene period.

Older publications describe the Aquia as being of Eocene age.[6]

Vertebrate paleobiota

Bony fish

Bony fish from the Aquia Formation
Genus Species Material Notes Images
Lepisosteus[2] L.sp. A Gar fish
Ostracion[2] O. meretrix An ostraciid (boxfish)[7]
Phyllodus[2] P.sp. A bonefish
Scomberomorus[2] S.sp. A mackrel fish
Labridae[2] Labridae indet. A wrasse

Chondrichthyes

Sharks

Sharks from the Aquia Formation
Genus Species Material Notes Images
Abdounia [2][8] A.beaugei A reqium shark
Anomotodon [2][9] A.novus A goblin shark
Carcharias [2][9] C.hopei A sand tiger shark
Cretolamna [2][9] C.appendiculata A megatooth shark
Delpitoscyllium [2] D.africanum
Foumtizia [2] F.abdouni
Galeorhinus[2] G.sp. A houndshark
Ginglymostoma [2] G.subafricanum A nurse shark
Heterodontus [2] H.lerichei A bullhead shark
Hypotodus [2] H.verticalis
Isurolamna [2] I.inflata A mackrel shark
Megasqualus [2] M.orpiensis
Notidanodon [2] N.loozi A cow shark
Odontaspis[2] O.loozi
Orectolobiform[2] O. Indet.
Otodus [2][10][9] O.obliquus A Megatooth shark
Pachygaleus [2] P.lefevrei
Palaeogaleus[2] P.sp.
Paleocarcharodon [2][10][9] P.orientalis A megatooth shark
Paleohypotodus [2][11] P.rutoti
Paraorthacodus [2] P.clarkii A Paraorthacodontid shark
Physogaleus [12] P.secundus A reqium shark
Premontreia [2] P.subulidens
Scyliorhinus[2] S.sp. A Scyliorhinid shark
Squalus S.sp. A dogfish
Squatina [2] S.prima An Angel shark
Striatolamia [2][9] S.macrota A Sand shark
S.striata
Triakis[2] T.sp. A Houndshark

Rays

Rays from the Aquia Formation
Genus Species Material Notes Images
Myliobatis[13] M.sp. A Mylobatiform ray
Burnhamia[2] B.sp. A devil ray
Coupatezia C. soutersi[2] A dasyatid ray
Dasyatis[2] D.sp
Hypolophodon H.sylvestris[2]
Ischyodus I. sylvestris[2]

Birds

Birds from the Aquia Formation
Genus Species Material Notes Images
Presbyornis P. isoni Humerus & alar phalanx A giant presbyornithid waterfowl.[14]
?Prophaeton ?P. sp. Distal end of right humerus A potential prophaetontid phaetontiform.[14]

Reptiles

Crocodylomorphs

Crocodylomorphs from the Aquia Formation
Genus Species Material Notes Images
Eosuchus E. minor A eusuchian crocodylomorph.[15]
?Hyposaurus H. sp. Teeth A potential dyrosaurid.[16]
Thoracosaurus[9] T. neocesariensis A eusuchian crocodylomorph.[7]

Turtles

Based on Weems (2014):[17]

Turtles from the Aquia Formation
Genus Species Material Notes Images
Aspideretoides A. virginianus A softshell turtle. Type locality of species.
Bothremydinae indet.[18] A marine side-necked turtle of uncertain affinities.
Catapleura C. coatesi A pancheloniid sea turtle. Type locality of species.
Eosphargis E. insularis A dermochelyid sea turtle.
Euclastes E. roundsi A pancheloniid sea turtle. Type locality of species.
Kinosternoidea indet. A kinosternoid turtle of uncertain affinities.
Osteopygis[19] O. kranzi[18] A freshwater macrobaenid turtle. Type locality of species.
Planetochelys P. savoiei A planetochelyid trionychian. Type locality of genus and species.
Tasbacka T. ruhoffi A pancheloniid sea turtle. Type locality of species.

Squamates

Squamates from the Aquia Formation
Genus Species Material Notes Images
Palaeophis P. virginianus A marine palaeophiid snake.[7]

Mammals

Based on Rose (2000):[20]

Mammals from the Aquia Formation
Genus Species Material Notes Images
Arctocyonidae indet. An arctocyonid of uncertain affinities.
Ectoganus E. cf. gliriformis A taeniodont.
?Phenacodus ?P. sp. A phenacodont.

Invertebrate paleobiota

Molluscs

Gastropods

Gastropods from the Aquia Formation
Genus Species Material Notes Images
Turritella [2][9][21] T.sp. very commonly found in the formation
Pleurotoma [22] P.potomacensis

Bivalves

Bivalves from the Aquia Formation
Genus Species Material Notes Images
Crassatelites [22] C.alaeformis
Cucullaea[23][22][24] C.gigantea
Dosiniopsis [22] D.lenticularis
Meretrix (bivalve)[22] M.ovata
Modiolus (bivalve)[22] M.alabamensis
Ostrea[25][22] O.compressirostra
Panopea[22] P.elongata
Venericardia[22] V.planicosta
Vulsella[25] V.alabamensis

Cephalopods

Sharks from the Aquia Formation
Genus Species Material Notes Images
Cimomia[26] C.marylandensis Uncommonly found

Mammal and bird fossils are also uncommonly found in the formation.[2]

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 Phatfossils Aquia Formation in Maryland and Virginia
  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. ^ Tolchester folio, Maryland, Folios of the Geologic Atlas 204, by B. L. Miller, E. B. Mathews, A. B. Bibbins, and H. P. Little, 1917.
  7. ^ a b c Weems, R. E. (1993). Stratigraphic distribution and bibliography of fossil fish, amphibians, and reptiles from Virginia (Report). U.S. Dept. of the Interior, Geological Survey.
  8. ^ Elasmo.com, The Life and Times of Long Dead Sharks, Abdounia, Jim Bourdon, author.
  9. ^ a b c d e f g h "Fossil Identification for the Potomac River".
  10. ^ a b "Potomac - Aquia Formation 3/15/18".
  11. ^ "Paleohypotodus?".
  12. ^ "Physogaleus secundus".
  13. ^ "Myliobatis".
  14. ^ a b Olson, Storrs L.; Olson, Storrs L. (1994). "A Giant Presbyornis (Aves, Anseriformes) And Other Birds From The Paleocene Aquia Formation Of Maryland And Virginia". Proceedings of the Biological Society of Washington. 107: 429––435.
  15. ^ Brochu, Christopher A. (2006). "OSTEOLOGY AND PHYLOGENETIC SIGNIFICANCE OF EOSUCHUS MINOR (MARSH, 1870) NEW COMBINATION, A LONGIROSTRINE CROCODYLIAN FROM THE LATE PALEOCENE OF NORTH AMERICA". Journal of Paleontology. 80 (1): 162–186. doi:10.1666/0022-3360(2006)080[0162:OAPSOE]2.0.CO;2. ISSN 0022-3360.
  16. ^ "The Marine Crocodilian Hyposaurus in North America", Ancient Marine Reptiles, Academic Press, pp. 375–397, 1997-01-01, doi:10.1016/B978-012155210-7/50020-X, retrieved 2026-02-15
  17. ^ Weems, Robert E. (2014-05-27). "Paleogene chelonians from Maryland and Virginia". PaleoBios. 31 (1). doi:10.5070/P9311022744. ISSN 0031-0298.
  18. ^ a b Weems, Robert E. (2014-05-27). "Paleogene chelonians from Maryland and Virginia". PaleoBios. 31 (1). doi:10.5070/P9311022744. ISSN 0031-0298.
  19. ^ Gentry, Andrew D.; Kiernan, Caitlín R.; Parham, James F. (2022-08-19). "A large non‐marine turtle from the Upper Cretaceous of Alabama and a review of North American "Macrobaenids"". The Anatomical Record. 306 (6): 1411–1430. doi:10.1002/ar.25054. ISSN 1932-8486. Archived from the original on 2022-08-19.
  20. ^ Rose, K. D. (2000). "Land-mammals from the late Paleocene Aquia formation: The first early Cenozoic mammals from Maryland". Proceedings of the Biological Society of Washington. 113 (4): 855–863. ISSN 0006-324X.
  21. ^ "Turritella sp".
  22. ^ a b c d e f g h i Virginia Division of Mineral Resources (1912). Bulletin. p. 200. fossils of the aquia formation.
  23. ^ "Cucullaea Gigantea". 15 May 2010.
  24. ^ "Views of the Mahantango: Cucullaea gigantea pelecypod from the Aquia Formation". 11 August 2014.
  25. ^ a b "Ostrea compressirostra".
  26. ^ "Sanity check: It's a Nautilus, right?".
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