USGS Mesozoic loc. 27505, Sun River area, Western Montana: Bathonian, Montana

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Bivalvia - Pectinida - Oxytomidae
Meleagrinella curta (Hall 1852)
Bivalvia - Myalinida - Inoceramidae
Inoceramus sp. Sowerby 1814
unclassified
Brachiopoda indet. Cuvier 1805
see common names

Geography
Country:United States State/province:Montana
Coordinates: 47.5° North, 112.8° West (view map)
Paleocoordinates:40.3° North, 52.2° West
Basis of coordinate:stated in text
Geographic resolution:small collection
Time
Period: Jurassic Epoch: Middle Jurassic
Stage: Bathonian 10 m.y. bin: Jurassic 4
Key time interval: Bathonian
Age range of interval: 168.2 - 165.3 m.y. ago
Stratigraphy
Formation:Sawtooth Member:Upper Siltstone
Stratigraphic resolution:group of beds
Stratigraphy comments: float in lower part of upper siltstone member of Sawtooth formation; the Upper Siltstone member is probably of Bathonian age
Lithology and environment
Primary lithology: lithified siltstone
Lithology description: The upper siltstone member consists of yellow calcareous siltstone and fine-grained sandstone.
Environment:marine indet.
Taphonomy
Size of fossils:macrofossils
Collection methods and comments
Collection methods:survey of museum collection
Reason for describing collection:biostratigraphic analysis
Museum repositories:USGS
Collection method comments: collection was made by M. R. Mudge in 1959
Metadata
Database number:68868
Authorizer:M. Aberhan Enterer:S. Nurnberg
Research group:marine invertebrate
Created:2007-02-10 08:48:06 Last modified:2007-02-10 10:48:06
Access level:the public Released:2007-02-10 08:48:05
Creative Commons license:CC BY
Reference information

Primary reference:
19843.1% R. W. Imlay. 1962. Jurassic (Bathonian or Early Callovian) Ammonites from Alaska and Montana. Geological Survey Professional Paper 374-C:1-32 [M. Aberhan/S. Nurnberg]