USGS Loc. 24860, Matanuska Valley-Nelchina [Matanuska Fm] (Cretaceous of the United States)

Where: Matanuska-Susitna County, Alaska (62.1° N, 147.8° W: paleocoordinates 70.3° N, 102.6° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Matanuska Formation, Campanian (83.6 - 72.1 Ma)

• STRATIGRAPHIC RELATIONS: From the Matanuska Fm, which unconformably overlie Early Cretaceous strata, including the Nelchina Limestone. AGE: Late Campanian or Maastrichtian, on the basis of ammonite biostratigraphy; Pachydiscus kamishakensis zone. STRATIGRAPHIC POSITION: From upper part of member 3, Matanuska Fm.

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified siltstone and lithified shale

• SPECIFIC LITHOLOGY: Siltstone and shale. LITHIFICATION: Lithified, on the basis of figured specimens.

Size class: macrofossils

Preservation: mold/impression

Collected by Grant & Fay in 1953; reposited in the USNM

Collection methods: surface (in situ),

• COLLECTOR: A. Grant & L. Fay, 1953. REPOSITORY: USNM.

Primary reference: D. L. Jones. 1963. Upper Cretaceous (Campanian and Maestrichtian) ammonites from southern Alaska. United States Geological Survey Professional Paper 432:1-53 [L. Ivany/L. Ivany/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 88822: authorized by Austin Hendy, entered by Austin Hendy on 21.04.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for ammonoids and bivalves. NOMENCLATURE: Authoritative publication, with slightly antiquated nomenclature, but with species-resolution identifications.
Bivalvia
 Myalinida - Inoceramidae
Inoceramus cf. subundatus, "Inoceramus aff. elegans" = Sphenoceramus elegans
"Inoceramus aff. elegans" = Sphenoceramus elegans Sokolow 1914 clam
Cephalopoda
 Phylloceratida - Phylloceratidae
"Neophylloceras hetonaiense" = Hypophylloceras (Neophylloceras) hetonaiense
"Neophylloceras hetonaiense" = Hypophylloceras (Neophylloceras) hetonaiense Matsumoto 1942 ammonite
 Ammonitida - Pachydiscidae
 Ammonitida - Diplomoceratidae
"Diplomoceras notabile" = Diplomoceras cylindraceum
"Diplomoceras notabile" = Diplomoceras cylindraceum Defrance 1816 ammonite