Columbia (USGS 15525) - Hickman (1980) (Eocene of the United States)

Also known as USGS 15525

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

• coordinate based on nearby landmark

• outcrop-level geographic resolution

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

• Middle member includes 500 m of predominantly light gray highly tuffaceous siltstone and mudstone beds with occasional ash layers and calcaerous concretionary beds. 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; poorly lithified, concretionary, tuffaceous, gray, calcareous siltstone and concretionary, tuffaceous, gray, calcareous mudstone

• No general geologic data provided
• Predominantly light gray highly tuffaceous siltstone and mudstone beds with occasional ash layers and calcaerous concretionary beds

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 40190: authorized by Austin Hendy, entered by Austin Hendy on 19.06.2004, edited by Mark Uhen

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for gastropoda
Gastropoda
 Cerithioidea - Turritellidae
Turritella keaseyensis Hickman 1980 turret shell
 Neogastropoda - Cancellariidae
Bonellitia (Admetula) tumida Hickman 1980 snail
 Sorbeoconcha - Cassidae
Echinophoria dalli Dickerson 1917 snail
 Sorbeoconcha - Bursidae
Olequahia schencki Durham 1944 frog shell
 Opisthobranchia - Cylichnidae
Scaphander impunctatus Hickman 1980 snail
Bivalvia
 Carditida - Carditidae
Cyclocardia moniligena2 Hickman 2015 clam
 Thraciida - Thraciidae
Thracia keaseyensis1 Hickman 2014 clam
 Cardiida - Cardiidae
Anechinocardium weaveri2 Anderson and Martin 1914 cockle