Where: Kodiak County, Alaska (56.5° N, 154.3° W: paleocoordinates 58.5° N, 148.0° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Narrow Cape Formation, Chattian (28.1 - 23.0 Ma)

• Unknown stratigraphic position within Narrow Cape Formation. Late Oligocene or early Miocene age. Overlies Early Oligocene Sitkinak Formation. Total thickness of formation about 210 m. The mollusks of the Narrow Cape Formation on Sitkinak Island are referable to the Juanian Stage of the provincial molluscan chronology of the Pacific Northwest (Oregon and Washington) (Addicott, 1976b; Allison, 1978). The Juanian Stage is coeval with the Echinophoria apta Zone of the Pacific Northwest (Armentrout, 1975; Addicott, 1976b; Allison, 1978) and is mostly of late Oligocene age and partly of early Miocene age (Allison, 1976, 1978). The Narrow Cape Formation on Sitkinak Island is older than the type Narrow Cape Formation of Kodiak Island. Echinophoria (=Liracassis) apta zone and type Juanian stage in the Pysht and Lincoln Creek Formations dated as Late Oligocene only by magnetostratigraphy in Prothero et al. (2003).

• group of beds-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, concretionary, pebbly siltstone

Size class: macrofossils

Preservation: concretion

Reposited in the USNM

Collection methods: quarrying,

• Collections housed in USGS, Menlo Park; University of Alaska, and USNM

Primary reference: R. C. Allison and L. Marincovich. 1981. A late Oligocene or earliest Miocene molluscan fauna from Sitkinak Island, Alaska. United States Geological Survey Professional Paper 1233:1-11 [A. Miller/A. Hendy/M. Krause]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 37662: authorized by Austin Hendy, entered by Austin Hendy on 19.03.2004

Creative Commons license: CC BY (attribution)