Assoc. VII (925-930 m) [Alfa Mbr, Santa Marta Fm] (Cretaceous of Antarctica)

Where: Antarctica (63.8° S, 58.0° W: paleocoordinates 61.6° S, 68.6° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Santa Marta Formation, Late/Upper Campanian (83.5 - 70.6 Ma)

• STRATIGRAPHIC RELATIONS: From the informal Alfa (Alpha) Mbr of the Santa Marta Fm, which regionally overlies the Hidden Lake Fm (Coniacian), and is overlain by the López de Bertodano Fm (Campanian-Maastrichtian). AGE: Late Campanian, on the basis of ammonite biostratigraphy. STRATIGRAPHIC POSITION: From near the middle of the regional section, between 925-930 m.

• bed-level stratigraphic resolution

Environment/lithology: offshore; lithified, silty sandstone

• ENVIRONMENT: Shallow siliciclastic marine setting.
• SPECIFIC LITHOLOGY: Sandy siltstone according to Fig. 2 of Olivero (1992). LITHIFICATION: Lithified, on the basis of figured specimens.

Size class: macrofossils

Preservation: cast, mold/impression

Collected by Olivero

Collection methods: surface (in situ),

• COLLECTOR: E. B. Olivero. REPOSITORY: Centro de Investigaciones en Recurso Geologicos (CIRGEO).

Primary reference: E. B. Olivero. 1992. Asociaciones de amonites de la formacion Santa Marta (Cretacio Tardio), Isla James Ross, Antartida. Geologia de la Isla James Ross 47-75 [A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 83385: authorized by Austin Hendy, entered by Austin Hendy on 19.08.2008

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for ammonoidea. Other taxa may be present, but were not listed in present biostratigraphic treatment. NOMENCLATURE: Not an authoritative publication, but with fairly modern nomenclature and species-resolution identifications where listed.
Show authors, comments, and common names
unclassified
  -
Oiphyllites sp.
Cephalopoda
 Ammonitida - Placenticeratidae
? Hoplitoplacenticeras sp., Metaplacenticeras sp.
? Hoplitoplacenticeras sp. Paulcke 1906 ammonite
Metaplacenticeras sp. Spath 1926 ammonite
 Ammonitida - Tetragonitidae
Gaudryceras sp.
Gaudryceras sp. de Grossouvre 1894 ammonite
 Ammonitida - Kossmaticeratidae
Neograhamites "sp. 1"
Neograhamites "sp. 1" Spath 1953 ammonite
 Ammonitida - Pachydiscidae
"Anapachydiscus "sp. 3"" = Menuites
"Anapachydiscus "sp. 3"" = Menuites Spath 1922 ammonite
 Ammonitida - Baculitidae
Baculites "sp. 2.", Baculites aff. subanceps
Baculites "sp. 2." Lamarck 1799 ammonite
Baculites aff. subanceps Haughton 1925 ammonite
SUBSPECIES: Baculites aff. subanceps pacificus