Undivided Middle Ordovician rocks, unit 3 (overview) (Ordovician to of the United States)

Where: Washington County, Virginia (36.8° N, 82.3° W: paleocoordinates 30.0° S, 66.5° W)

• coordinate stated in text

• local area-level geographic resolution

When: Chazy to Chazy (466.0 - 457.5 Ma)

• "Because of lack of definitive lithologic and faunal data and the narrow outcrop belt, these rocks are mapped as Middle Ordovician, undivided."

• formation-level stratigraphic resolution

Environment/lithology: shallow subtidal; lithified, concretionary, gray, red limestone and shelly/skeletal, brown, calcareous shale

• light gray, thin bedded, knobby limestone with two thick beds of pink, coarse grained limestone; some brown, calcareous clay shale in lower portion; fossils abundant

Primary reference: C. S., J.r. Bartlett and H. W. Webb. 1971. Geology of the Bristol and Wallace quadrangles, Virginia. Virginia Division of Mineral Resources Report of Investigations 25:1-93 [J. Alroy/M. Sommers/P. Wagner]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 6991: authorized by John Alroy, entered by Mike Sommers on 18.04.2000

Creative Commons license: CC BY (attribution)

Taxonomic list

Chlorophyceae
  - Receptaculitidae
Gastropoda
 Murchisoniina - Lophospiridae
? Lophospira sp. Whitfield 1886 snail
Rhynchonellata
 Orthida - Plaesiomyidae
 Orthida - Hesperorthidae
? Hesperorthis sp. Schuchert and Cooper 1931
Stenolaemata
 Cystoporata - Constellariidae
Constellaria sp. Dana 1846
 Cystoporata - Ceramoporidae
Scenellopora sp. Ulrich 1882
? Coeloclema sp. Ulrich 1882
 Cryptostomata - Rhinidictyidae
 Cryptostomata -
  - Phylloporinidae
Phylloporina sp. Foerste 1887
 Trepostomata - Trematoporidae
 Trepostomata -
Halloporina sp. Astrova 1965
 Trepostomata - Heterotrypidae
Heterotrypa sp. Nicholson 1879
 Trepostomata - Dittoporidae
Hemiphragma sp. Ulrich 1893
 Rhabdomesida - Rhabdomesidae
Deuteropoda
  -
Ostracoda indet. Latreille 1802 ostracod
ostracod fragments
Cystoidea
  -
Cystoidea indet. von Buch 1846
systoid calyx fragments