Birbury Farm (Eocene of South Africa)

Where: South Africa (33.5° S, 26.9° E: paleocoordinates 42.8° S, 16.5° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Bathurst Formation, Ypresian (56.0 - 47.8 Ma)

• STRATIGRAPHIC RELATIONS: From Alexandria Formation, which unconformably overlies Late Cretaceous Sundays River Fm in places, and is overlain by eolian calcarenites. Unit later subdivided as Bathurst Formation (Le Roux 1989). AGE: Much discussed, although not clearly in text, to range from Miocene to Pleistocene, but also possible Eocene (see Haughton pers. comm., cited in text). King (1972) assigned a Pliocene age, but more recently an undivided Mio-Pliocene range is used. Siesser and Miles (1979) also studied the Birbury microfossils and identified at least 14 species of calcareous nannofossils and six species of planktonic foraminifera. These were mainly Paleogene forms, plus a few longer-ranging types. None were specifically Neogene. Age ranges of several of the nannofossils and foraminifera, especially Morozovella subbotinae and Chiasmolithus solitus overlap, thus indicating an Early Eocene age for the Birbury deposits. STRATIGRAPHIC POSITION: According to Le Roux (1989), nautilids come from a 1 m-thick unit beginning 1.95 m above the base of the outcrop.

• group of beds-level stratigraphic resolution

Environment/lithology: shoreface; poorly lithified, medium-grained, calcareous sandstone

• ENVIRONMENT: Lithology and fossil (micro and macro) assemblages as well as the physical conditions of the fossils indicate a fairly high energy depositional environment, probably ranging from the shoreface to the foreshore.
• SPECIFIC LITHOLOGY: Medium-grained (0.25mm) calcareous sand, well sorted, rounded grains, with calcarenite nodules, containing abundant, mainly fragmented shells. LITHIFICATION: Poorly lithified, based on facies description, which is distinguished from "ccompact crystalline" and "porous, loosely-cemented" adjacent descriptions.

Size class: macrofossils

Collection methods: COLLECTOR: Unknown collector. REPOSITORY: Unknown repository.

Primary reference: A. Ruddock. 1966. The Tertiary limestone of the southern coastal regions of Cape Province, South Africa. Sedimentary Basins of the African Coasts 49-62 [A. Hendy/A. Hendy]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 77526: authorized by Austin Hendy, entered by Austin Hendy on 14.01.2008

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for gastropoda and bivalvia, and also mentioning foraminifera, brachiopoda, bryozoa, crustacea, and sharks. NOMENCLATURE: Not an authoritative publication, and with relatively antiquated nomenclature, commonly not assigned to species resolution.
Nodosariata
 Polymorphinida - Polymorphinidae
Tubothalamea
 Miliolida - Miliolidae
Sigmoilina sp. Schlumberger 1887
Spiroloculina sp. d'Orbigny 1826
Trillina sp. Munier-Chalmas and Schlumberger 1893
 Miliolida - Hauerinidae
 Miliolida - Fabulariidae
 Miliolida - Soritidae
Foraminifera
 Globigerinoidea - Globigerinidae
"Globigerina conglobata" = Globigerinoides conglobatus Brady 1879
Globigerina bulloides d'Orbigny 1826
 Lituolida - Lituolidae
"Textularia agglutinans" = Textularia jurassica Guembel 1862
Textularia gramen dOrbigny 1846
 Nummulitacea - Discocyclinidae
 Nummulitacea - Nummulitidae
 Rotaliacea - Rotaliidae
Globothalamea
 Rotaliida - Discorbidae
 Rotaliida - Nonionidae
Foraminifera
  -
Rhynchonellata
 Terebratulida - Cancellothyrididae
Terebratulina sp. d'Orbigny 1847
Gastropoda
  -
Cyclostoma indet. Draparnaud 1801 snail
Cephalopoda
 Nautilida - Aturiidae
Aturia sp. Bronn 1838 nautiloid
Bivalvia
 Ostreida - Ostreidae
Ostrea sp. Linnaeus 1758 oyster
 Pectinida - Pectinoidae
Pecten sp. Müller 1776 scallop
Deuteropoda
  -
Ostracoda indet. Latreille 1802 ostracod