Aquia Formation facts for kids
Quick facts for kids Aquia FormationStratigraphic range: Late Paleocene ~59.0–55.5Ma |
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Thecachampsa crocodile coprolite (Aquia Formation; King George County, Virginia)
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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. It consists of clayey, silty, very shelly, glauconitic sand. Fossil records indicate that this stratigraphic unit was created during the Paleocene.
The Aquia formation was named for Aquia Creek where it is exposed in cliff faces along the banks.
Contents
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. It occurs between 0 and 100 feet thick. Quartz and phosphatic pebbles and/or very coarse glauconitic quartz sand mark the base of the unit. 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.
Stratigraphy
The Aquia formation is overlain by the Nanjemoy Formation and overlies the Brightseat Formation.
The Aquia formation is broken down into two members: the lower Piscataway member and upper Paspotansa member.
Age
The Aquia Formation is thought to be 59.0-55.5 million years old. The Piscataway member is 59-56.25 million years old, and the Paspotansa member is 56-55.5 million years old.
Fossils
Vertebrates
Bony fish
- Lepisosteus
- Ostracion
- Phyllodus
- Scomberomorus
- Wrasse
Chondrichthyes
Sharks
- Abdounia beaugei
- Anomotodon novus
- Carcharias hopei
- Cretolamna appendiculata
- Delpitoscyllium africanum
- Foumtizia abdouni
- Galeorhinus
- Ginglymostoma subafricanum
- Heterodontus lerichei
- Hypotodus verticalis
- Isurolamna inflata
- Megasqualus orpiensis
- Notidanodon loozi
- Odontaspisx loozi
- Orectolobiform
- Otodus obliquus
- Pachygaleus lefevrei
- Palaeogaleus
- Paleocarcharodon orientalis
- Paleohypotodus rutoti
- Paraorthacodus clarkii
- Physogaleus secundus
- Premontreia subulidens
- Scyliorhinus
- Squalus
- Squatina prima
- Striatolamia macrota
- Striatolamia striata
- Triakis
Rays
- Myliobatis
- Burnhamia
- Coupatezia soutersi
- Dasyatis
- Hypolophodon sylvestris
- Ischyodusx sylvestris
Reptiles
Crocodylians
- Eosuchus
- Hyposaurus
- Thecachampsa
- Thoracosaurus
Turtles
- Trionyx
Mammals
Mammal fossils are extremely rare.
Birds
Bird fossils are extremely rare.
Molluscs
Gastropods
- Turritella is very common.
- Pleurotoma potomacensis
Bivalves
- Crassatelites alaeformis
- Cucullaea gigantea
- Dosiniopsis lenticularis
- Meretrix ovata
- Modiolus alabamensis
- Ostrea compressirostra
- Panopea elongata
- Venericardia planicosta
- Volsella alabamensis
Cephalopods
- Cimomia marylandensis is present but uncommon.
See also
In Spanish: Formación Aquia para niños