Horizon C, Blackborough, Devon (Blackdown Greensand) (Cretaceous of the United Kingdom)

Where: England, United Kingdom (50.9° N, 3.3° W: paleocoordinates 39.2° N, 2.3° E)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Blackdown Greensand Formation, Albian (113.0 - 100.5 Ma)

• Horizon C - 3.2 m above the base of the section. This is possibly equivalent top Downes (1882) Bed 8 or 9. The total section thickness was 7 m. Blackdown Greensand is an informal unit, describing a 30 m+ Cretaceous sequence of decalcified sands with layers of cherty sandstone concretions. The Greensand unconformably overlies Triassic and Jurassic strata..

• bed-level stratigraphic resolution

Environment/lithology: coastal; poorly lithified, concretionary, shelly/skeletal, cherty/siliceous sandstone

• Shallow marine sandbar complex, influenced by weak tides and periodic storms.
• Shelly sandstone with siliceous concretions.

Size class: macrofossils

Collection methods: No repository mentioned, but presumably this is the British Geological Survey.

Primary reference: M. A. Woods and N.S. Jones. 1996. The sedimentology and biostratigraphy of a temporary exposure of Blackdown Greensand (Lower Cretaceous, upper Albian) at Blackborough, Devon. Proceedings of the Ussher Society 9(1):37-40 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 51674: authorized by Austin Hendy, entered by Austin Hendy on 09.06.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for Mollusca. Nomenclature appears to be fair. Key top abundance: p=present, c=common, vc=very common
Gastropoda
 Cerithioidea - Turritellidae
Turritella (Torquesia) granulata n. sp. Sowerby 1827 turret shell
Bivalvia
 Ostreida - Gryphaeidae
 Pholadida - Corbulidae
 Cardiida - Veneridae
"Callistina plana" = Aphrodina plana
"Callistina plana" = Aphrodina plana Sowerby 1813 venus clam
 Carditida - Astartidae
 Trigoniida - Steinmanellidae