Columbia (USGS 15274) - Hickman (1980) (Eocene of the United States)

Also known as USGS 15274

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 40183: 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
 Opisthobranchia - Cylichnidae
Scaphander impunctatus Hickman 1980 snail
Scaphander stewarti Durham 1944 snail
 Epitonioidea - Epitoniidae
 Sorbeoconcha - Naticidae
Natica (Natica) weaveri Tegland 1933 moon snail
 Neogastropoda - Turridae
Procerapex bentsonae1 Durham 1944 turrid
Bivalvia
 Cardiida - Cardiidae
Anechinocardium weaveri3 Anderson and Martin 1914 cockle
 Cardiida - Tellinidae
Moerella quasimacoma3 Hickman 2015 tellin clam
 Cardiida - Veneridae
Lamelliconcha clarki3 Dickerson 1917 venus clam
 Thraciida - Thraciidae
Thracia keaseyensis2 Hickman 2014 clam