Yokoun River - Skonun Formation (Miocene of Canada)

Where: British Columbia, Canada (53.8° N, 132.1° W: paleocoordinates 51.3° N, 128.7° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Skonun Formation, Late/Upper Miocene (11.6 - 5.3 Ma)

• Exposure of 12 m of sandstone overlain by 3 m of mudstone. The mudstone is unaccessible except for talus containing the collection piled at the base of the cliff. Acila empirensis in the assemblages indicates a late Late Miocene age. This unit can be correlated to the Empire Fm of Oregon. The fauna is similar to the Yakataga Fm of Alaska and presumably is of similar age.

• bed-level stratigraphic resolution

Environment/lithology: offshore; lithified mudstone

• Inner or mid-shelf environment; 20-50 m consistent with sedimentological evidence which suggests a tidal-shelf setting. Comparable in faunal composition to the Empire Fm (Washington) and Yakataga Fm (Alaska).
• Massive mudstone. Material appears to be in lithified rock based on plates.

Size class: macrofossils

Preservation: cast, mold/impression

Primary reference: J. M. White, L. Marincovitch, and R. Higgs. 1994. New Miocene fossil discoveries in the Skonun Formation, Queen Charlotte Islands, British Columbia, and implications for basin stratigraphy and climate. Geological Survey of Canada Bulletin 479:85-100 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 57689: authorized by Austin Hendy, entered by Austin Hendy on 17.12.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

Gastropoda
 Cerithioidea - Turritellidae
Turritella sp. Lamarck 1799 turret shell
Bivalvia
 Cardiida - Cardiidae
? Clinocardium sp. Keen 1936 cockle
"Clinocardium coosense" = Clinocardium (Clinocardium) coosense Dall 1909 cockle
 Thraciida - Periplomatidae
? Periploma sp. Schumacher 1816 clam
 Nuculida - Nuculidae
Acila sp., "Acila (Truncacila) empirensis" = Acila (Truncacila) castrensis
Acila sp. Adams and Adams 1858 divaricate nutclam
"Acila (Truncacila) empirensis" = Acila (Truncacila) castrensis Hinds 1843 divaricate nutclam