Trinity Islands (M6585) (Miocene to of the United States)

Also known as USGS M6585

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)

• Middle of 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 37657: 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
 Mytilida - Mytilidae
Crenella porterensis Weaver 1916 mussel
 Cardiida - Veneridae
 Cardiida - Tellinidae
Macoma sp. Leach 1819 tellin clam
"Macoma twinensis" = Macoma (Macoma) twinensis Clark 1925 tellin clam
Macoma (Macoma) moesta Deshayes 1855 tellin clam
Subspecies: Macoma (Macoma) moesta alaskana
 Hiatellida - Hiatellidae
"Hiatella arctica" = Hiatella (Hiatella) arctica
"Hiatella arctica" = Hiatella (Hiatella) arctica Linnaeus 1767 clam
 Thraciida - Periplomatidae
Gastropoda
 Neogastropoda - Buccinidae
Buccinum sp. Linnaeus 1758 true whelk
 Neogastropoda - Fasciolariidae
Priscofusus aff. stewarti Tegland 1933 snail
 Naticoidea - Naticidae
Naticidae indet. Guilding 1834 moon snail
 Sorbeoconcha - Turritellidae
"Turritella (Hataiella) sp." = Hataiella
"Turritella (Hataiella) sp." = Hataiella Kotaka 1959 turret shell
  - Neptuneidae
Bruclarkia sp. Trask 1926 snail
Scaphopoda
 Dentaliida - Dentaliidae