False Pass (M7146) (Miocene of the United States)

Also known as USGS M7146

Where: Aleutians East County, Alaska (55.0° N, 162.8° W: paleocoordinates 56.0° N, 161.2° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Tachilni Formation, Tortonian (11.6 - 7.2 Ma)

• Formation crops out continuously from the coast west of Cape Tachilni from Morzhovoi Bay to Flase Pass and possibly of Deer Island. Thickness of the Tachilni Fm is not known because its base is not exposed, but is estimated to be as much as 460 m thick, although not more than 250 m and any outcrop. Disconformably overlies volcaniclastic Belkofski Fm, and is unconformably overlain by Pliocene-Holocene volacanic flows and breccia.

• bed-level stratigraphic resolution

Environment/lithology: coastal; fine-grained, medium, brown, gray sandstone

• Composed mostly of dark brown to light greenish-gray, fine- to coarse-grained sandstone, abundant similarly colored siltstone, with some pebble conglomerate and black shale....mainly a fine- to medium-grained sandstone.

Size class: macrofossils

Reposited in the CAS, USNM

Collection methods: quarrying,

• Also collections at University of Alaska (UA), Fairbanks, Alaska

Primary reference: L. Marincovich. 1983. Molluscan paleontology, paleoecology, and North Pacific correlations of the Miocene Tachilni Formation, Alaska Peninsula, Alaska. Bulletin of American Paleontology 84(317):1-155 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 37401: authorized by Austin Hendy, entered by Austin Hendy on 14.03.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for molluscan taxa
unclassified
  -
Gastropoda
  -
Gastropoda indet. Cuvier 1795 snail
 Trochoidea - Turbinidae
 Sorbeoconcha - Naticidae
Naticidae indet., "Natica (Cryptonatica) cf. clausa" = Cryptonatica affinis
Naticidae indet. Guilding 1834 moon snail
"Natica (Cryptonatica) cf. clausa" = Cryptonatica affinis Gmelin 1791 moon snail
 Neogastropoda - Buccinidae
Neptunea sp. Röding 1798 true whelk
 Neogastropoda - Conidae
Bivalvia
 Nuculanida - Yoldiidae
"Yoldia (Cnesterium) scissurata" = Yoldia (Cnesterium) aeolica
"Yoldia (Cnesterium) scissurata" = Yoldia (Cnesterium) aeolica Valenciennes 1846 clam
 Nuculida - Nuculidae
"Acila (Truncacila) empirensis" = Acila (Truncacila) castrensis
"Acila (Truncacila) empirensis" = Acila (Truncacila) castrensis Hinds 1843 divaricate nutclam
 Mytilida - Crenellidae
Musculus (Musculus) niger Gray 1824 mussel
 Pectinida - Pectinoidae
"Chlamys (Swiftopecten) cosibensis" = Chlamys (Chlamys) cosibensis
"Chlamys (Swiftopecten) cosibensis" = Chlamys (Chlamys) cosibensis Yokoyama 1911 scallop
Subspecies: Chlamys (Swiftopecten) cosibensis cosibensis
 Arcida - Glycymerididae
Glycymeris grewingki Dall 1909 clam
 Cardiida - Cardiidae
"Clinocardium ciliatum" = Clinocardium (Ciliatocardium) ciliatum, Clinocardium hannibali, "Clinocardium meekianum" = Clinocardium (Clinocardium) meekianum, "Clinocardium cf. pristinum" = Clinocardium (Clinocardium) pristinum
"Clinocardium ciliatum" = Clinocardium (Ciliatocardium) ciliatum Fabricius 1780 cockle
"Clinocardium meekianum" = Clinocardium (Clinocardium) meekianum Gabb 1866 cockle
"Clinocardium cf. pristinum" = Clinocardium (Clinocardium) pristinum Keen 1954 cockle
 Cardiida - Tellinidae
"Peronidia (Peronidia) lutea" = Tellina (Megangulus) lutea Gray 1828 tellin clam
Subspecies: Peronidia aff. P. lutea alternidentata
Macoma sp. Leach 1819 tellin clam
Macoma (Macoma) golikovi Scarlato and Kafanov 1988 tellin clam
 Cardiida - Mactridae
Spisula sp., "Spisula (Mactromeris) polynyma" = Mactromeris polynyma, "Spisula (Mactromeris) brevirostrata" = Mactromeris brevirostrata, "Spisula (Mactromeris) cf. albaria" = Mactromeris albaria
Spisula sp. Gray 1837 clam
"Spisula (Mactromeris) polynyma" = Mactromeris polynyma Stimpson 1860 clam
"Spisula (Mactromeris) brevirostrata" = Mactromeris brevirostrata Packard 1916 clam
"Spisula (Mactromeris) cf. albaria" = Mactromeris albaria Conrad 1848 clam
 Pholadida - Myidae
Mya (Mya) truncata Linnaeus 1758 softshell clam
Mya (Arenomya) elegans Eichwald 1871 softshell clam
 Solenida - Pharidae
Siliqua cf. alta Broderip and Sowerby I 1829 clam
 Hiatellida - Hiatellidae
 Thraciida - Periplomatidae