Columbia (USGS 25028) - Hickman (1980) (Eocene of the United States)

Also known as USGS 25028

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 39952: 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
 Seguenzioidea - Eucyclidae
Bathybembix columbiana Dall 1909 snail
 Epitonioidea - Epitoniidae
Epitonium (Boreoscala) keaseyense Durham 1937 wentletrap
 Neogastropoda - Buccinidae
Trophonopsis platacantha Hickman 1980 true whelk
 Neogastropoda - Conidae
Conus weltoni Hickman 1980 cone shell
 Neogastropoda - Ptychatractidae
Exilia bentsonae Hickman 1980 snail
 Sorbeoconcha - Cassidae
Echinophoria dalli Dickerson 1917 snail
Bivalvia
 Cardiida - Tellinidae
Moerella quasimacoma Hickman 2015 tellin clam
 Carditida - Carditidae
Cyclocardia moniligena n. sp. Hickman 2015 clam