USGS Loc. 24226, Matanuska Valley-Nelchina [Matanuska Fm] (Cretaceous of the United States)

Where: Matanuska-Susitna County, Alaska (61.9° N, 147.7° W: paleocoordinates 70.2° N, 102.8° 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

Reposited in the USNM

Collection methods: surface (in situ),

• COLLECTOR: Grantz et al, 1952. 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 88819: 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.
Show authors, comments, and common names
Bivalvia
 Myalinida - Inoceramidae
Inoceramus cf. subundatus
Cephalopoda
 Ammonitida - Tetragonitidae
Gaudryceras tenuiliratum
Gaudryceras tenuiliratum Yabe 1903 ammonite