Depositional framework of Upper Cretaceous fluvio-deltaic coals, south-central Alberta

Conference · Tue Jan 01 00:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6309995

Waheed, A; Miall, A D

Coal-bearing strata of the Horseshoe Canyon Formation near Drumheller represent a progradational fluvio-deltaic system. Lower delta-plain facies include meandering channels flanked by levees, crevasse splays and channels, bays, and well-drained and poorly-drained swamps. Upper delta-plain facies are similar except that flood basins and oxbow lakes replace bays. The ten main coal seams compose 5% of the section and are bituminous with 0.6-1.0% sulfur. They are up to 2 m thick and most extend across the 11 by 7 km area of detailed study. In order of importance, they represent bay-floor accumulations, interfleuve swamps, and oxbow-fills. In interchannel bays and flood basins, coal deposition was frequently interrupted either by influx of crevasse-sands or inundation by bays. Coal seams that accumulated in low-lying areas of flood basins are thin and are commonly interbedded with carbonaceous shales. Oxbow-fill coals are thin, lenticular and arcuate. Thickness and lateral continuity of fluvio-deltaic coals were controlled by crevassing, differential compaction, and post-depositional channel erosion. Flood basins and bays were distinguished with palynomorphs. Deltaic and fluvial channels are 1-6 m thick fining-upward sequences with well-developed epsilon cross-stratification. An embedded Markov chain analysis suggest strong asymmetrical ordering within the coal-bearing sequence. Facies paths indicate depositional control by such autocyclic and allocyclic processes as lateral accretion, crevassing, avulsion, subsidence, marine inundation, overbank flooding, water-table fluctuation, and growth and demise of vegetation.

• Research Organization: Kent State Univ., OH (USA)
• OSTI ID: 6309995
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ALBERTA
COAL DEPOSITS
DEPOSITION
STRATIGRAPHY
ALLUVIAL DEPOSITS
CRETACEOUS PERIOD
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
LITHOLOGY
CANADA
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGY
MESOZOIC ERA
MINERAL RESOURCES
NORTH AMERICA
RESOURCES
011000* - Coal
Lignite
& Peat- Reserves
Geology
& Exploration