Columbia (USGS 15284) - Hickman (1980) (Eocene of the United States)

Also known as USGS 15284

Where: Columbia County, Oregon (45.8° N, 123.3° W: paleocoordinates 46.1° N, 111.0° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Lower Member (Keasey Formation), Priabonian (38.0 - 33.9 Ma)

• Lower member consists of 0-150 m of dark gray, highly micaceous, laminated siltstone and interbedded mudsone. Glaucontitc layers are not uncommon. The Keasey Formation consists of a maximum of 700 m of gray tuffaceous marine siltstone and massive mudstone discontinuously exposed in quaries, road and railway cuts, and along major drainages. The Keasey Fm overlies the late Eocene Cowlitz Fm, and underlies the Pittsburg Bluff Fm. Fm is subdivided into three informal members.

• bed-level stratigraphic resolution

Environment/lithology: deep-water; micaceous, gray siltstone and mudstone

• No general geologic data provided
• Dark gray, highly micaceous, laminated siltstone and interbedded mudstone

Size class: macrofossils

Reposited in the USNM

Collection methods: quarrying,

• USGS collections are reposited in USNM. Other collections are reposited at Stanford University (SU), UC Berkeley Museum of Paleontology (UCMP), Cal. Acad. Sci. (CAS), Oregon State Dept. of Geology and Mineral Industries (DOGAMI)

Primary reference: C. S. Hickman. 1980. Paleogene Marine Gastropods of the Keasey Formation in Oregon. Bulletins of American Paleontology 78(310):1-112 [L. Ivany/E. Kowalski/M. Uhen]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 39945: authorized by Austin Hendy, entered by Austin Hendy on 12.06.2004, edited by Mark Uhen

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for gastropoda
Gastropoda
 Epitonioidea - Epitoniidae
 Sorbeoconcha - Bursidae
Olequahia schencki Durham 1944 frog shell
 Sorbeoconcha - Naticidae
Bivalvia
 Thraciida - Thraciidae
Thracia keaseyensis1 Hickman 2014 clam
 Cardiida - Veneridae
Lamelliconcha clarki2 Dickerson 1917 venus clam
 Cardiida - Cardiidae
Anechinocardium weaveri2 Anderson and Martin 1914 cockle