Juniper Fork (USGS Mes. loc. 24011): Early Jurassic, Alaska

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Crinoidea - Isocrinida - Pentacrinitidae
Pentacrinus subangularis Miller 1821
var. alaska
see common names

Geography
Country:United States State/province:Alaska
Coordinates: 69.4° North, 147.0° West (view map)
Paleocoordinates:63.0° North, 50.3° West
Geographic resolution:small collection
Time
Period: Jurassic Epoch: Early Jurassic
10 m.y. bin: Jurassic 1-3
*Period:Early/Lower Jurassic
Key time interval: Early Jurassic
Age range of interval: 201.4 - 174.7 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Formation:Kingak Shale
Stratigraphic resolution:bed
Stratigraphy comments: Lower part of Kingak Shale. "Lower Jurassic."
Lithology and environment
Primary lithology:black lithified "shale"
Secondary lithology: ironstone
Lithology description: ironstone lenses in black fissile shale.
Environment:marine indet. Tectonic setting:foreland basin
Geology comments: "[These sediments] were deposited in an eastward-trending trough about 150 mi wide...the trough was bounded on the S by a rising landmass from which most of the sediments were derived. It was bounded on the N by the Barrow Platform..."

[ergo, foreland basin]

Taphonomy
Modes of preservation:body
Collection methods and comments
Collection methods:field collection
Reason for describing collection:biostratigraphic analysis
Museum repositories:USGS
Metadata
Database number:5230
Authorizer:J. Alroy Enterer:M. Sommers
Research group:marine invertebrate
Created:1999-09-02 17:48:01 Last modified:2001-08-30 17:52:51
Access level:the public Released:2000-11-20 13:53:25
Creative Commons license:CC BY
Reference information

Primary reference:
313. R. W. Imlay. 1955. Characteristic Jurassic Mollusks from northern Alaska. United States Geological Survey Professional Paper 274-D:69-96 [J. Alroy/M. Sommers]