Cambridge Greensand
Cambridge Greensand | |
---|---|
Stratigraphic range: Earliest Cenomanian ~ | |
Type | Member |
Unit of | West Melbury Marly Chalk Formation |
Underlies | Chalk Group |
Overlies | Gault Formation |
Thickness | 0.1–1 m (0.33–3.28 ft) |
Lithology | |
Primary | Glauconitic marl |
Other | Phosphorite |
Location | |
Coordinates | 52°12′N 0°06′E / 52.2°N 0.1°E |
Approximate paleocoordinates | 41°00′N 1°48′E / 41.0°N 1.8°E |
Region | England |
Country | UK |
Extent | North Hertfordshire and Cambridgeshire |
Type section | |
Named for | Cambridge |
Location | Arlesey Brickpit |
The Cambridge Greensand is a geological unit in England whose strata are earliest Cenomanian in age. It lies above the erosive contact between the Gault Formation and the Chalk Group in the vicinity of Cambridgeshire, and technically forms the lowest member bed of the West Melbury Marly Chalk Formation. It is a remanié deposit, containing reworked fossils of late Albian age, including those of dinosaurs and pterosaurs.
Description
The lithology is made out of glauconitic marl, described as a "chalk mud", containing abundant ostracod, coccolith and foram remains, with a concentration of phosphatic nodules and bones at the base.
Vertebrate paleofauna
Birds
- Enaliornis barrette - "Braincases, vertebrae, pelvis [and] limb elements.."
- E sedgwicki - "Hindlimb elements."
- E. seeleyi - "Assorted cranial and postcranial elements"
Dinosaurs
Ornithischians
- Anoplosaurus curtonotus - "Partial postcranium."
- A. major - "Cervical vertebrae." "Vertebrae."
- Acanthopholis eucercus - "[Two] caudal centra."
- Acanthopholis platypus (in part) - "Phalanx, caudal centra."
- Acanthopholis macrocercus (aka Syngonosaurus) - "Osteoderms." "Vertebrae, fragmentary skeleton elements."
- Acanthopholis stereocercus - "Osteoderms." "Vertebrae."
- Eucercosaurus tanyspondylus - "Vertebrae."
- Trachodon cantabrigiensis - "Dentary tooth."
Saurischians
- Macrurosaurus semnus - "Caudal vertebrae"
Pterosaurs
- Amblydectes crassidens
- A. eurygnathus
- Camposipterus colorhinus
- C. nasutus
- Camposipterus sedgwickii
- Draigwenia platystomus
- Lonchodraco machaerorhynchus
- Lonchodraco microdon
- Ornithocheirus simus
- Nicorhynchus capito
- "Ornithocheirus" denticulatus
- "Ornithocheirus" polyodon
- Ornithostoma sedgwicki
Ichthyosaurs
- Cetarthrosaurus walkeri
- Maiaspondylus cantabrigiensis (originally Ophthalmosaurus)
- Pervushovisaurus campylodon
- Sisteronia seeleyi
Lepidosauria
Invertebrates
Ammonites
- Salaziceras (Salaziceras) salazacense