James Ross Island [upper Lachman Crags 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

• local area-level geographic resolution

When: Lachman Crags Member (Santa Marta Formation), Campanian (83.6 - 72.1 Ma)

• STRATIGRAPHIC RELATIONS: From the Lachman Crags Mbr of the Santa Marta Fm, which locally overlies the Hidden Lake Fm (Coniacian), and is overlain by the López de Bertodano Fm. AGE: Santonian-Campanian, on the basis of ammonite biostratigraphy; placed in Campanian as from the upper part of the unit. STRATIGRAPHIC POSITION: From beds in the upper part of the member.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified sandstone and lithified siltstone

• ENVIRONMENT: Siliciclastic marine setting.
• SPECIFIC LITHOLOGY: Sandstone and siltstone, with occasional conglomerate and shell beds according to Fig. 5 of Crame et al. (1991). LITHIFICATION: Lithified, on the basis of figured specimens.

Size class: macrofossils

Preservation: cast, mold/impression

Collection methods: COLLECTOR: Multiple collectors, including J.A. Crame and M.R.A Thompson. REPOSITORY: Not stated, but presumably British Antarctic Survey and Oxford University Museum (OUM).

Primary reference: J. A. Crame, D. Pirrie, J. B. Riding and M. R. A. Thomson. 1991. Campanian-Maastrichtian (Cretaceous) stratigraphy of the James Ross Island area, Antarctica. Journal of the Geological Society, London 148:1125-1140 [A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 83352: authorized by Austin Hendy, entered by Austin Hendy on 19.08.2008

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Not exhaustive but inclusive of representative and biostratigraphically important ammonoidea, bivalvia, and other taxa. 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.
unclassified
  -
Dinophyceae
  -
Nelsoniella sp. Cookson and Eisenack 1960
Xenikoon australis Cookson and Eisenack 1960
 Peridiniales - Peridiniaceae
Isabelidinium cretaceum Lentin and Williams 1977
Isabelidinium cf. belfastense Lentin and Williams 1976
 Gonyaulacales - Ceratiaceae
 Life -
Amphidiadema denticulata Cookson and Eisenack 1960
Cephalopoda
 Ammonitida - Diplomoceratidae
 Ammonitida - Baculitidae
Baculites rectus Marshall 1926 ammonite
Baculites bailyi Woods 1906 ammonite
 Ammonitida - Pachydiscidae
Eupachydiscus paucituberculatus, "Anapachydiscus sp." = Menuites
"Anapachydiscus sp." = Menuites Spath 1922 ammonite
Possibly Menuites (Neopachyceras) of Kennedy et al. (2007)
 Ammonitida - Kossmaticeratidae
""Karapadites" aff. centinelaensis" = Kossmaticeras (Karapadites) ammonite
Neograhamites taylori Spath 1953 ammonite
 Ammonitida - Desmoceratidae
"Kitchinites (Neopuzosia) cf. japonica" = Kitchinites (Neopuzosia) japonicus Spath 1922 ammonite
Bivalvia
 Myalinida - Inoceramidae
 Trigoniida - Trigoniidae
Trigoniidae indet. Lamarck 1819 clam