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

Conference · Tue Jan 01 04:00:00 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-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

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