John P. Haiduk
The Britt sandstones record a regressive-transgressive couplet in response to deltaic progradation, abandonment, and subsidence in the southeastern Anadarko basin, during the Late Mississippian. Four principal facies compose the sequence: (1) deltaic bar-finger sands, (2) shelf sand ridges, (3) delta-destructional sand bars, and (4) storm deposits.
Platform sands were reworked into shelf sand ridges in mid-shelf, with elongated delta-destructional bars forming along the subsiding delta front. Storm surges mixed coarse-grained coquinoid sands with muds and silts typical of lower energy environments. Scouring of storm deposits into underlying sediments was common.
Petrologically mature, with the exception of storm deposits, each facies is quartzitic, with trace amounts of potassic and plagioclase feldspar, rock fragments, and heavy minerals. Glauconite is restricted to delta-destructional bars. Storm deposits are dominated by fragmented fossils and sparse oolitic units.
Numerous episodes of diagenetic activity have altered extensively the reservoir quality of these sands. Volumetrically, silica and carbonate cementation were the most important diagenetic processes. Chlorite is the dominant authigenic clay mineral. Porosity is predominantly secondary, and the dissolution of quartz and quartz overgrowths provided much of the reservoir in these highly productive strata.
AAPG Search and Discovery Article #91039©1987 AAPG Mid-Continent Section Meeting, Tulsa, Oklahoma, September 27-29, 1987.