Trinity Islands (M6583) (Miocene to of the United States)

Also known as USGS M6583

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)

• 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, 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 37651: 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.
 Carditida - Carditidae
Cyclocardia sp. Conrad 1867 clam
Cyclocardia cf. tokunagai Yokoyama 1924 clam
 Pholadida - Myidae
Mya (? Arenomya) grewingki Makiyama 1934 softshell clam
 Cardiida - Tellinidae
Macoma sp. Leach 1819 tellin clam
"Macoma cf. twinensis" = Macoma (Macoma) twinensis Clark 1925 tellin clam
Macoma (Macoma) golikovi Scarlato and Kafanov 1988 tellin clam
 Hiatellida - Hiatellidae
"Hiatella arctica" = Hiatella (Hiatella) arctica
"Hiatella arctica" = Hiatella (Hiatella) arctica Linnaeus 1767 clam
 Nuculida - Nuculidae
Acila sp. Adams and Adams 1858 divaricate nutclam
 Neogastropoda - Buccinidae
 Naticoidea - Naticidae
Naticidae indet., "Natica (Cryptonatica) clausa" = Cryptonatica affinis
Naticidae indet. Guilding 1834 moon snail
"Natica (Cryptonatica) clausa" = Cryptonatica affinis Gmelin 1791 moon snail
 Sorbeoconcha - Turritellidae
"Turritella (Hataiella) sp." = Hataiella
"Turritella (Hataiella) sp." = Hataiella Kotaka 1959 turret shell