Aquia Formation
Geologic formation in the United States
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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]
| Aquia Formation | |
|---|---|
| Stratigraphic range: Late Paleocene ~ | |
Boulder of Aquia Formation along Chester River. Contains casts of large mollusks. (c. 1917) | |
| 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 | 38.3°N 77.3°W |
| Approximate paleocoordinates | 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 |
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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
Vertebrate paleobiota
Bony fish
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. | _(18152226245).jpg) | |
| 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. Type locality of species.[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
Mammal and bird fossils are also uncommonly found in the formation.[2]
