USGS Loc. 16398, Matanuska Valley-Nelchina [Matanuska Fm] (Cretaceous of the United States)

Where: Matanuska-Susitna County, Alaska (61.8° N, 148.1° W: paleocoordinates 70.3° N, 104.5° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Matanuska Formation, Late/Upper Campanian (83.5 - 70.6 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 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 Waring in 1932; reposited in the USNM

Collection methods: surface (in situ),

• COLLECTOR: G.A. Waring, 1932. 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 88816: authorized by Austin Hendy, entered by Austin Hendy on 21.04.2009, edited by Matthew Clapham

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.
Cephalopoda
 Phylloceratida - Phylloceratidae
"Neophylloceras hetonaiense" = Hypophylloceras (Neophylloceras) hetonaiense Matsumoto 1942 ammonite
Phyllopachyceras forbesianum d'Orbigny 1850 ammonite
 Ammonitida - Tetragonitidae
Pseudophyllites indra Forbes 1846 ammonite
Gaudryceras tenuiliratum Yabe 1903 ammonite
 Ammonitida - Desmoceratidae
"Desmophyllites phyllimorphum" = Desmophyllites diphylloides
"Desmophyllites phyllimorphum" = Desmophyllites diphylloides Forbes 1846 ammonite
 Ammonitida - Pachydiscidae
 Ammonitida - Nostoceratidae
Didymoceras aff. hornbyense Whiteaves 1876 ammonite
 Ammonitida - Diplomoceratidae
"Diplomoceras notabile" = Diplomoceras cylindraceum
"Diplomoceras notabile" = Diplomoceras cylindraceum Defrance 1816 ammonite
Bivalvia
 Myalinida - Inoceramidae