Al Gata Member, Wadi Thamat Formation (Eocene of Libya)

Where: Libya (29.8° N, 16.6° E: paleocoordinates 23.2° N, 12.6° E)

• coordinate stated in text

• basin-level geographic resolution

When: Al Gata Member (Wadi Thamat Formation), Lutetian (47.8 - 41.3 Ma)

• LITHOSTRATIGRAPHIC RELATIONSHIPS: From the Al Gata Mbr of the Wadi Thamat Fm, which overlies the Al Jir (middle Eocene) and is overlain by the Thmed Al Qusur Mbr of the Wadi Thamat Fm (Priabonian). AGE: Lutetian, on the basis of microfossil (foraminiferal) and macrofossil biostratigraphy. THICKNESS: averages 90 m across its range.

• member-level stratigraphic resolution

Environment/lithology: shallow subtidal; lithified, shelly/skeletal, green, yellow, calcareous marl

• ENVIRONMENT: Shallow marine littoral to neritic environment of deposition.
• GENERAL LITHOLOGY: Greenish-yellow to buff marls grading into calcilutite crowded with oysters with subordinate intercalations of yellowish white organodetrital limestone. LITHIFICATION: Lithified, not stated, but apparent from facies description.

Size classes: macrofossils, microfossils

Collection methods: surface (in situ),

• COLLECTORS: Not stated, possibly multiple collectors. REPOSITORY: Unknown.

Primary reference: M. F. Megerisi and V. D. Mamgain. 1980. The Upper Cretaceous-Tertiary Formations of northern Libya: a synthesis. Department of Geological Researches and Mining Bulletin 12:1-85 [A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 42138: authorized by Austin Hendy, entered by Austin Hendy on 24.07.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Limited, but including bivalvia, gastropoda, echinoids, algae, and foraminifera. NOMENCLATURE: Somewhat antiquated nomenclature, but identified to species and subgenus resolution.
Nodosariata
 Nodosariida - Nodosariidae
Lagena sp. Walker and Boys 1784
Frondicularia sp. Defrance 1824
Globothalamea
 Rotaliida - Discorbidae
Discorbis sp. Lamarck 1804
 Rotaliida - Nonionidae
Nonion sp. Monfort 1808
Foraminifera
 Rotalioidea - Elphidiidae
Elphidium sp. Monfort 1808
 Lituolida - Haplophragmoididae
 Rotaliacea - Rotaliidae
Gastropoda
 Sorbeoconcha - Strombidae
"Rostellaria sp." = Tibia
"Rostellaria sp." = Tibia Röding 1798 true conch
Bivalvia
 Pectinida - Anomiidae
Carolia sp. Cantraine 1838 scallop
 Ostreida - Gryphaeidae
"Ostrea exogyroides" = Praeexogyra dubiensis
"Ostrea exogyroides" = Praeexogyra dubiensis Contejean 1859 oyster
 Ostreida - Ostreidae
"Ostrea multicostata" = Cubitostrea multicostata, Ostrea oviola
"Ostrea multicostata" = Cubitostrea multicostata Deshayes 1832 oyster
SUBSPECIES: O. multicostata strictiplicata
Echinoidea
 Echinolampadoida - Echinolampadidae
Echinolampas sp. Gray 1825 sea urchin