USGS 3717-CO - Hillard Limestone, Yukon River (west ridge) area (Cambrian of the United States)

Also known as 61AMc941

Where: Alaska (65.0° N, 141.2° W: paleocoordinates 6.8° N, 66.2° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Hillard Limestone Formation, Dresbachian (497.0 - 485.4 Ma)

• STRATIGRAPHIC RELATIONS: From Hillard Limestone, which regionally overlies the Early Cambrian Adams Argillite and is unconformably overlain by the lower part of the Rhoad River Formation. AGE: Dresbachian on occurence of faunal assemblages similar to that of the Dunderbergia zone of the Great Basin. STRATIGRAPHIC POSITION: At base of 50 ft section, bed of limestone at top of a unit of black siltstone that seems to be locally developed.

• bed-level stratigraphic resolution

Environment/lithology: lithified limestone

• ENVIRONMENT: Carbonate deposition, intermittent turbulent conditions.
• SPECIFIC LITHOLOGY: Limestone. LITHIFICATION: Lithified, based on age and facies.

Size class: macrofossils

Reposited in the USNM

• COLLECTOR: J.C. Mclik (1961). REPOSITORY: USGS and USNM.

Primary reference: A.R. Palmer. 1968. Cambrian trilobites of East-Central Alaska. United States Geological Survey Professional Paper 559(B) [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 64798: authorized by Austin Hendy, entered by Austin Hendy on 15.09.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Only trilobites (following monograph focus). No other taxa listed. IDENTIFIER: A.R. Allison. NOMENCLATURE: Authoritative publication, though probably somewhat age nomeclature, with species designations.
Trilobita
 Corynexochida - Corynexochidae
Corynexochus plumula Whitehouse 1939 trilobite
 Olenida - Aphelaspidae
Olenaspella "evansi" Kobayashi 1936 trilobite
Artiopoda
 Agnostida - Diplagnostidae
Pseudagnostus sp. Jaekel 1909