Trinity Islands (M6499) (Miocene to of the United States)

Also known as USGS M6499, UCMP IP 22709

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)

• 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 37652: 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
  - Neptuneidae
Neptuneidae indet. Stimpson 1865 snail
 Neotaenioglossa - Calyptraeidae
Calyptraea cf. diegoana Conrad 1855 slipper shell
 Cerithioidea - Turritellidae
"Turritella (Hataiella) cf. chichibuensis" = Hataiella
"Turritella (Hataiella) cf. chichibuensis" = Hataiella turret shell
 Neogastropoda - Buccinidae
 Neogastropoda - Siphonaliidae
 Neogastropoda - Fasciolariidae
 Neogastropoda - Turridae
Parasyrinx sp. Finlay 1924 turrid
 Sorbeoconcha - Naticidae
Neverita (Neverita) washingtonensis Weaver 1916 moon snail
"Natica (Cryptonatica) clausa" = Cryptonatica affinis Gmelin 1791 moon snail
Bivalvia
 Cardiida - Cardiidae
Clinocardium cf. makiyamae Kamada 1962 cockle
 Cardiida - Tellinidae
Macoma (Macoma) golikovi Scarlato and Kafanov 1988 tellin clam
"Macoma twinensis" = Macoma (Macoma) twinensis Clark 1925 tellin clam
 Hiatellida - Hiatellidae
Hiatella arctica Linnaeus 1767 clam
 Carditida - Carditidae