ABSTRACT

In the southern half of the Manila Embayment, southern Alabama, the Smackover Formation comprises one stratigraphic sequence, 30 to 120 m (100 to 400 ft) thick, which was deposited within the late early Oxfordian-early Kimmeridgian depositional cycle. Analysis of depositional facies associations reveals that the Smackover carbonate platform was initially a carbonate shelf (lower parasequence set) that changed rapidly to a carbonate ramp (upper parasequence set) owing to an increase in the rate of relative sea level rise during the depositional cycle. Shelfal facies comprising the lower Smackover parasequence set are bounded at the base by a marine flooding surface located above terrestrial clastic facies (Norphlet Formation). The lower Smackover parasequence set is separated from the upper Smackover by a second marine flooding surface. The upper Smackover parasequence set is bounded at the top by a type-2 unconformity beneath anhydritic sabkha facies (Buckner Anhydrite Member of the Hayneville Formation).