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: Narrrow Cape Formaton 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.
Bivalvia
 Carditida - Carditidae
 Cardiida - Mactridae
Spisula cf. hannibali Clark and Arnold 1923 clam
 Cardiida - Veneridae
Liocyma cf. fluctuosa Gould 1841 venus clam
 Cardiida - Tellinidae
Macoma sp. Leach 1819 tellin clam
 Cardiida - Cardiidae
? Serripes hamiltonensis Clark 1932 cockle
 Hiatellida - Hiatellidae
"Hiatella arctica" = Hiatella (Hiatella) arctica
"Hiatella arctica" = Hiatella (Hiatella) arctica Linnaeus 1767 clam
Gastropoda
 Neogastropoda - Buccinidae
Buccinum sp. Linnaeus 1758 true whelk
 Neogastropoda - Fasciolariidae
 Neogastropoda - Volutidae
"Musashia (Musashia) sp." = Fulgoraria (Musashia)
"Musashia (Musashia) sp." = Fulgoraria (Musashia) volute
 Neogastropoda - Turridae
Parasyrinx sp. Finlay 1924 turrid
 Tonnoidea - Cassidae
 Sorbeoconcha - Turritellidae
"Turritella (Hataiella) sp." = Hataiella
"Turritella (Hataiella) sp." = Hataiella Kotaka 1959 turret shell
  - Neptuneidae
? Beringius sp. Dall 1886 snail