Trinity Islands (M6576) (Miocene to of the United States)

Also known as USGS M6576, UCMP IP22734

Where: Kodiak County, Alaska (56.5° N, 154.3° W: paleocoordinates 57.8° N, 150.6° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Narrow Cape Formation, Early/Lower Miocene to Early/Lower Miocene (23.0 - 11.6 Ma)

• Lower Narrow Cape Formation. Late Oligocene or early Miocene age. Overlies Early Oligocene Sitkinak Formation. Total thickness of formation about 210 m.

• bed-level stratigraphic resolution

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

• Mainly siltstone with some beds contaioning scattered pebbles and cobbles, and scattered to locally abundant calcareous concretions. Occasional thin beds of very fine sandstone. Megafossils throughouty siltstone and commonly in concretions.

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 37643: authorized by Austin Hendy, entered by Austin Hendy on 19.03.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Representative of mollusca; foraminifera listed in reference for some localities but are not entered.
Gastropoda
 Cerithioidea - Turritellidae
"Turritella (Hataiella) sp." = Hataiella
"Turritella (Hataiella) sp." = Hataiella Kotaka 1959 turret shell
 Sorbeoconcha - Naticidae
Naticidae indet. Guilding 1834 moon snail
Polinices (Euspira) ramonensis Clark 1918 moon snail
Bivalvia
 Carditida - Carditidae
 Hiatellida - Hiatellidae
Hiatella arctica Linnaeus 1767 clam
 Cardiida - Tellinidae
Macoma (Macoma) golikovi Scarlato and Kafanov 1988 tellin clam
"Macoma twinensis" = Macoma (Macoma) twinensis Clark 1925 tellin clam
Macoma (Macoma) moesta Deshayes 1855 tellin clam
Subspecies: Macoma (Macoma) modesta alaskana
Macoma (Macoma) calcarea Gmelin 1792 tellin clam