USGS M4680 (Oligocene of the United States)

Also known as Psycht area

Where: Clallam County, Washington (48.2° N, 122.1° W: paleocoordinates 47.9° N, 113.2° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Clallam Formation, Chattian (28.1 - 23.0 Ma)

• GENERAL STRATIGRAPHY: The Clallam Formation is a predominantly marine sandstone with minor conglomerate and siltstone exposed along the Strait of Juan de Fuca in northwestern Washington. Marine molluscs occur throughout the 600 to 800 m thick formation but are especially abundant in the lowermost 240 m. Pillarian Stage afe, a provincial time stratigraphic unit of late early Miocene age. Age emended to Chattian follow more recent work [Hendy, 7/2016].

• bed-level stratigraphic resolution

Environment/lithology: offshore; lithified sandstone

• All Clallam Formation assemblages represent inner sublittoral depths (less than about 100 m). Qualitative analysis of these assemblages indicates a gradual shallowing during deposition of the formation. The highest strata in the formation contain coal and are presumably non-marine.
• Sandstone with minor conglomerate and siltstone.

Size class: macrofossils

Preservation: mold/impression

Collected by Addicott in 1971; reposited in the USGS

Collection methods: quarrying,

• REPOSITORY: USGS (Menlo Park).

Primary reference: W.O. Addicott. 1976. Molluscan paleontology of the lower Miocene Clallam Formation, northwestern Washington. United States Geological Survey Professional Paper 976:1-44 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 37575: authorized by Austin Hendy, entered by Austin Hendy on 17.03.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Only molluscan taxa listed.
 Cardiida - Mactridae
"Spisula albaria" = Mactromeris albaria
"Spisula albaria" = Mactromeris albaria Conrad 1848 clam
 Cardiida - Tellinidae
Tellina emacerata Conrad 1849 tellin clam
 Nuculida - Nuculidae
"Acila cf. conradi" = Acila (Truncacila) conradi
"Acila cf. conradi" = Acila (Truncacila) conradi Meek 1864 divaricate nutclam
 Protobranchia - Yoldiidae
Yoldia supramontereyensis Arnold 1908 clam
 Naticoidea - Naticidae
Natica vokesi Addicott 1966 moon snail
 Dentaliida - Dentaliidae
Dentalium schencki Moore 1963 tusk shell