Trinity Islands (M1489) (Miocene to of the United States)

Also known as USGS M1489

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)

• 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.

• 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 37660: 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 - Cassidae
"Echinophoria apta" = Liracassis apta
"Echinophoria apta" = Liracassis apta Tegland 1931 snail
 Neogastropoda - Volutidae
Musashia (Musashia) sp. Hayashi 1966 volute
 Neogastropoda - Buccinidae
Buccinum sp. Linnaeus 1758 true whelk
? Beringius sp. Dall 1886 true whelk
 Neogastropoda - Fasciolariidae
 Neogastropoda - Turridae
Parasyrinx sp. Finlay 1924 turrid
Bivalvia
 Cardiida - Mactridae
Spisula cf. hannibali Clark and Arnold 1923 clam
 Cardiida - Veneridae
Liocyma cf. fluctuosa Gould 1841 venus clam
 Cardiida - Cardiidae
? Serripes hamiltonensis Clark 1932 cockle
 Cardiida - Tellinidae
Macoma sp. Leach 1819 tellin clam
 Hiatellida - Hiatellidae
Hiatella arctica Linnaeus 1767 clam
 Carditida - Carditidae