Sample #94W-6a - Myrtle Group (Oregon) (Cretaceous of the United States)

Also known as Record 73

Where: Douglas County, Oregon (43.0° N, 123.5° W: paleocoordinates 41.1° N, 72.0° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Dotham Formation (Myrtle Group), Valanginian (139.8 - 132.9 Ma)

• Presumably from Dotham Formation, Myrtle Group. Lithostratigraphy is unclear. The Myrtle Group consists of Late Jurassic and Early to Middle Cretaceos turbidite and mass flow deposits considered to be either arc basin and or post-orogenic flysch basins syntectonic with waning phases of arc collapse. The Dotham Formation comprises low grade sub-pumpellyite facies, and pumpellyite bearing graywacke and semischistose graywacke, and scattered limestone. Macrofossil biostratigraphy suggests an Valanginian age.

• bed-level stratigraphic resolution

Environment/lithology: basinal (); lithified sandstone

• No environmental interpetation, though given basinal lithofacies are described, a basinal (siliciclastic) environment is chosen by enterer. "Turbidite and mass flow deposits considered to be either arc basin and or post-orogenic flysch basins syntectonic with waning phases of arc collapse"
• Presumably from low-graded metamorphosed graywackes.

Size class: macrofossils

Collection methods: quarrying,

• Unknown collector. Collections presumably reposited at USGS Menlo Park or USNM.

Primary reference: R. E. Wells, A. S. Jayko, A.R. Niem, G. Black, T. Wiley, E. Baldwin, K. Molenaar, K.L. Wheeler, C.B. DuRoss and R.W. Givler. 2000. Geologic Map and Database of the Roseburg 30 x 60' Quadrangle, Douglas and Coos Counties, Oregon. United States Geological Survey Open-File Report 00-367 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 52313: authorized by Austin Hendy, entered by Austin Hendy on 03.08.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

• Unknown identifier.
Bivalvia
 Pectinida - Buchiidae
Buchia pacifica Jeletsky 1965 scallop