Sample #93DB-3 - Myrtle Group (Oregon): Berriasian, Oregon
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Bivalvia
- Pectinida
- Buchiidae
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Buchia pacifica
Jeletsky 1965
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| see common names | |||||||
Geography
| Country: | United States | State/province: | Oregon | County: | Douglas |
| Coordinates: | 43.0° North, 123.1° West (view map) | ||||
| Paleocoordinates: | 40.3° North, 71.6° West | ||||
| Basis of coordinate: | stated in text | ||||
| Geographic resolution: | outcrop |
Time
| Period: | Cretaceous | Epoch: | Early/Lower Cretaceous |
| Stage: | Berriasian | 10 m.y. bin: | Cretaceous 1 |
| Key time interval: | Berriasian | ||
| Age range of interval: | 145.00000 - 139.80000 m.y. ago |
Stratigraphy
| Geological group: | Myrtle | Formation: | Dotham | ||
| Local section: | Dodson Butte | ||||
| Regional section: | Tyee | ||||
| Stratigraphic resolution: | bed | ||||
| Stratigraphy comments: 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 Berriasian age. | |||||
Lithology and environment
| Primary lithology: | lithified sandstone |
| Includes fossils? | Y |
| Lithology description: Presumably from low-graded metamorphosed graywackes, specifically sandstone. | |
| Environment: | basinal (siliciclastic) |
| Geology comments: 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" | |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
Collection methods and comments
| Collection methods: | selective quarrying,field collection |
| Reason for describing collection: | biostratigraphic analysis |
| Collection method comments: Collected by D. Bukry (1993). Collections presumably reposited at USGS Menlo Park or USNM. | |
| Taxonomic list comments:Identified by D. Bukry. | |
Metadata
| Also known as: | Record 61 | ||
| Database number: | 52311 | ||
| Authorizer: | A. Hendy | Enterer: | A. Hendy |
| Modifier: | A. Hendy | Research group: | marine invertebrate |
| Created: | 2005-08-03 10:20:53 | Last modified: | 2013-11-25 13:37:23 |
| Access level: | the public | Released: | 2005-08-03 10:20:53 |
| Creative Commons license: | CC BY | ||
Reference information
Primary reference:
| 14064. | 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] |