Bed 13 (of Douvillé) - Operculina limestone (Paleocene of China)

Where: Tibet, China (32.0° N, 90.0° E: paleocoordinates 16.7° N, 78.7° E)

• outcrop-level geographic resolution

When: Zongpu Formation, Thanetian (59.2 - 56.0 Ma)

• STRATIGRAPHIC RELATIONS: Bed 13, named here as "Operculina limestone", which overlies Bed 12, a "gastropod limestone", and is overlain by Bed 13, a "calcareous shales". Approximately equivalent to the lower Ranikot Formation of India. "Operculina Limestone" now belongs to member 3 of the Zongpu Formation. AGE: Formerly thought to be Danian in age, reasessed by Vredenburg and Cotter to be Early Eocene on the basis of macrofossil biostratigraphic correlations. According to Wen et al., member 3 belongs to zone SBZ4 of late Paleocene age. STRATIGRAPHIC POSITION: From bed within thicker succession.

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, shelly/skeletal limestone

• ENVIRONMENT: Not reported in text.
• SPECIFIC LITHOLOGY: Limestone, presumably skeletal. LITHIFICATION: Unknown, but assigned to lithified as stated to be limestone.

Size class: macrofossils

Collected by Hayden

Collection methods: surface (in situ),

• COLLECTOR: H. Hayden, presumably earliest 1900's. REPOSITORY: Presumably, the Geological Survey of India.

Primary reference: G. P. Cotter. 1921. The age of the so-called Danian fauna from Tibet. Records of the Geological Survey of India 59:410-418 [A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 76994: authorized by Austin Hendy, entered by Austin Hendy on 13.12.2007

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for gastropoda, bivalvia, cephalopoda, and foraminifera. NOMENCLATURE: Antiquated, but determined to species-resolution.
Cephalopoda
 Nautilida - Nautilidae
"Nautilus pseudobouchardi" = Eutrephoceras charpentieri, "Nautilus cf. rota" = Paracymatoceras rota
"Nautilus pseudobouchardi" = Eutrephoceras charpentieri Leymerie 1851 nautiloid
"Nautilus cf. rota" = Paracymatoceras rota Blanford 1861 nautiloid
Gastropoda
 Neritoidea - Neritidae
 Architaenioglossa - Ampullinidae
"Natica cf. flemingi" = Pachycrommium flemingi
"Natica cf. flemingi" = Pachycrommium flemingi d'Archiac and Haime 1854 snail
 Sorbeoconcha - Campanilidae
 Neogastropoda - Volutidae
Lyria sp. Gray 1847 volute
Bivalvia
 Pectinida - Limidae
Lima squamifera file clam
 Lucinida - Lucinidae
Corbis cf. lamellosa Deshayes 1824 clam
Foraminifera
 Rotaliacea - Calcarinidae
 Nummulitacea - Nummulitidae
 Rotaliina - Lepitorbitoididae