USGS 18779 - Wolf Creek Highway [Pittsburg Bluff Fm] (Oligocene of the United States)

Where: Washington County, Oregon (45.6° N, 123.2° W: paleocoordinates 45.3° N, 112.4° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Pittsburg Bluff Formation, Rupelian (33.9 - 28.1 Ma)

• From lower Pittsburg Bluff Formation. The Pittsburg Bluff Formation conformably overlies the Keasey Formation (late Eocene and early Oligocene) and is conformably overlain by the Scappose Formation (late Oligocene and early Miocene). Parts of the formation are lithologically similar and therefore the stratigraphic position of exposures are sometimes uncertain. The estimated thickness for the entire formation is 200 ml the thickest continuous section of the formation is 100 m thick.

• bed-level stratigraphic resolution

Environment/lithology: coastal; fine-grained, gray sandstone

• Massive olive-gray fine-grained sandstone, with concretions, trough shaped prisms, silstone rip-up clasts.

Size class: macrofossils

Reposited in the CAS, UCMP, UW

Collection methods: quarrying,

• Material housed in the USGS, Menlo Park. Also collections from UCMP, CAS, Stanford University (SU), University of Washington (UW), University of Oregon (UO), and the Academy of Natural Sciences of Philadelphia (ANSP)

Primary reference: E. J. Moore. 1976. Oligocene marine mollusks from the Pittsburg Bluff Formation in Oregon. United States Geological Survey Professional Paper 922:1-66 [A. Miller/A. Hendy/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 37822: authorized by Austin Hendy, entered by Austin Hendy on 24.03.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Very complete for mollusca
Gastropoda
 Neogastropoda - Nassariidae
Molopophorus gabbi Dall 1909 snail
 Neogastropoda - Fasciolariidae
Perse pittsburgensis Durham 1944 snail
Bivalvia
 Nuculida - Nuculidae
Acila (Truncacila) shumardi Dall 1909 divaricate nutclam