Clatsop (UGSG 5403) - #4 (Moore, 1963) (Miocene of the United States)

Also known as Locality #4 (Moore, 1963); USGS 5403

Where: Clatsop County, Oregon (46.2° N, 123.8° W: paleocoordinates 46.0° N, 119.2° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Lower Sandstone Member (Astoria Formation), Middle Miocene (16.0 - 11.6 Ma)

• Lower Sandstone Member. Astoria Formation has been used as a name for almost all of the marine middle Miocene sedimentary rocks of Washington and Oregon although these correlations are poorly constrained. The formation has been divided into three members: a lower sandstone, a shale, and an upper sandstone. These rocks form the northern limb of a syncline, the asis of which is exposed east of Astoria, and the syncline trends NE and plunges to the SW. The Astoria Formation is intermittently exposed; theya re faulted and exposures are interupted by volcanic rocks and slides. The maximum thickness of any exposure is 25 feet.

• bed-level stratigraphic resolution

Environment/lithology: coastal; poorly lithified, fine-grained, concretionary, silty, carbonaceous sandstone

• Astoria Formtaion is faulted and interupted in exposure by volcanic rocks and land slides.
• Fine-grained sandstone, alternating with sandy shale in whcih coal pebbles, small round concretions, and fossils are abundant

Size class: macrofossils

Preservation: concretion, replaced with other

Reposited in the CAS, USNM

Collection methods: salvage, quarrying, surface (float),

• Collected by R.F. Rogers and G.A. Macready, 1910. Collections reside in the Californian Academy of Sciences, the U.S. National Museum, and presumably the USGS.

Primary reference: E. J. Moore. 1963. Miocene marine mollusks from the Astoria Formation in Oregon. United States Geological Survey Professional Paper 419 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 39583: authorized by Austin Hendy, entered by Austin Hendy on 31.05.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for mollusca
 Arcida - Arcidae
Anadara (Anadara) devincta ark
indetermined form
 Pectinida - Pectinoidae
 Carditida - Carditidae
Cyclocardia subtenta Conrad 1849 clam
 Cardiida - Tellinidae
Tellina emacerata Conrad 1849 tellin clam
 Lucinida - Lucinidae
Lucinoma acutilineata Conrad 1849 clam
 Neogastropoda - Buccinidae
 Neogastropoda - Nassariidae
"? Hinia lincolnensis" = Nassarius (Demondia) lincolnensis
"? Hinia lincolnensis" = Nassarius (Demondia) lincolnensis Anderson and Martin 1914 snail
 Ficoidea - Ficidae
Ficus modesta fig shell
 Naticoidea - Naticidae
 Sorbeoconcha - Turritellidae
Turritella oregonensis Conrad 1849 turret shell
  - Neptuneidae
 Dentaliida - Dentaliidae
Dentalium (? Dentalium) pseudonyma Pilsbry and Sharp 1898 tusk shell