Depositional history and correlation problems of the Anderson-Dietz coal zone, southeastern Montana

Journal Article · Wed Apr 01 04:00:00 EST 1981 · Mt. Geol.; (United States)

OSTI ID:6151261

Sholes, M A; Cole, G A

The Roland, Smith, Anderson, and Dietz coal beds of the Tertiary Fort Union Formation in Big Horn County, Montana, split and merge in a complex pattern which makes standard methods of correlation by stratigraphic interval impossible. The splitting and merging of the coal beds can be related to the distribution of the associated rocks, particularly the sandstone beds which can be divided into crevasse splay and channel fill facies. The clastic partings and intervals between coal beds represent short term input of crevasse splay clastics into interdistributary peat swamps or the longer term migration of fluvial channels through them. This interpretation means that the coal beds studied in Big Horn County are not separate isochronous beds but are irregularly distributed throughout the stratigraphic interval containing them, and coal beds near the base of the interval can frequently be physically correlated with coal beds near the top of the interval. It is therefore recommended that coal correlations not be carried over long distances or that new names not be assigned to coal beds within the interval without very detailed stratigraphic support.

• Research Organization: Montana Bureau of Mines and Geology, Butte
• OSTI ID: 6151261
• Journal Information: Mt. Geol.; (United States), Journal Name: Mt. Geol.; (United States) Vol. 18:2; ISSN MOGEA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
011000* -- Coal
Lignite
& Peat-- Reserves
Geology
& Exploration
CENOZOIC ERA
COAL DEPOSITS
DEPOSITION
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGY
MINERAL RESOURCES
MONTANA
NORTH AMERICA
RESOURCES
ROCKS
ROCKY MOUNTAIN REGION
SANDSTONES
SEDIMENTARY ROCKS
SEDIMENTATION
STRATIGRAPHY
TERTIARY PERIOD
USA