Tillamook (UGSG 15301) - #42 (Moore, 1963) (Miocene of the United States)

Also known as Locality #42 (Moore, 1963); USGS 15301

Where: Tillamook County, Oregon (45.4° N, 123.9° W: paleocoordinates 45.2° N, 119.3° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

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

• From unknown horizon. 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, silty, calcareous shale and fine-grained, silty, calcareous sandstone

• Astoria Formtaion is faulted and interupted in exposure by volcanic rocks and land slides.
• Strata exposed consist shale varying in silt and sand content, siltstone, fine-grained sandstone with varying amounts of silt, coarse-grained sandstone, conglomerate, and tuff. Calcareous silty shale and fine-grained silty sandstone generally predominate.

Size class: macrofossils

Preservation: concretion, replaced with other

Reposited in the CAS, USNM

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

• Collected by W.C. Warren and R.M. Grivetti, 1952. 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 39586: authorized by Austin Hendy, entered by Austin Hendy on 31.05.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Exhaustive for mollusca
Bivalvia
 Cardiida - Veneridae
"Chione (Securella) ensifera" = Securella
"Chione (Securella) ensifera" = Securella venus clam
Gastropoda
  - Neptuneidae