Review of Carbonate Sand-Belt Deposition of Ooid Grainstones and Application to Mississippian Reservoir, Damme Field, Southwestern Kansas

Abstract

Ooid shoals are present (1) in the high-energy zones of carbonate ramps, (2) across broad shelves, and (3) along rimmed carbonate shelf edges. Shoals generally form as depositional strike-oriented or dip-oriented sand bodies in these settings. Marine sand belts, locally present along the shelf edge of the Great Bahama Little Bahama Banks, are depositional strike-oriented sand shoals made of flood ramps, shields, and channels that terminate in spillover lobes. Their geometry results from an interplay between storm-generated and tide-generated currents with the sea floor. Mississippian oolitic limestones (St. Louis Limestone B-zone), whose geometries resemble modern Bahamian ooid shoals, produce oil and are current exploration targets in southwestern Kansas (Hugoton embayment). Thus, a sedimentological and stratigraphic study of a producing field (Damme field, Finney County, Kansas) and a comparison to modern ooid sand bodies were justified. The St. Louis Limestone is overlain by the Ste. Genevieve Limestone (nonproductive) in Damme field. Both formations consist of five lithofacies: (1) skeletal wackestones in an open marine shelf, (2) porous, skeletal, ooid grainstone in a marine sand belt, (3) sandy, peloid-ooid, skeletal grainstone in a mobile grain shoal, (4) quartz-arenite in a tidal inlet, and (5) fenestral lime mudstone in an intertidal mud flat. Porous grainstones of lithofacies 2 form an elongate (northwest-southeast), lenticular body 10 mi (16 km) long, 2 mi (3.2 km) wide, and up to 18 ft (5.5 m) thick. Its shape and geometry are nearly the same as the marine sand belts of the Bahamas. Lithofacies arrangements indicate two styles of shallowing-upward depositional cycles; the lower St. Louis cycle was deposited during a relative sea level rise, and the overlying Ste. Genevieve cycles were deposited after a relative drop of sea level, an event signalled by the influx of siliciclastic sediments into the carbonate shelf from the Central Kansas uplift and/or Transcontinental arch.