Sullivan et al. (1997) reinterpreted the Shannon Sandstone at Hartzog Draw field to be a series of stacked, upward-coarsening tidal bars. Thickness trends are interpreted to be the product of variable erosion associated with southeast-trending incised valleys. Three major, unconformity-bounded depositional sequences have been identified: (a) the lowermost "Copenhagen Blue" sequence is composed of distal tidal-bar deposits sitting atop offshore mudstones of the Cody Shale; (b) the "Crimson Red" sequence is the main reservoir interval and is dominated by high-reservoir-quality, proximal tidal-bar sandstones; (c) the highly incised, overlying "Canary Yellow" sequence is composed of distal tidal bars and offshore mudstones. After Sullivan et al. (1997).
Reprinted with permission of Soc. Sedimentary Geology (SEPM).
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