Sequences within the Mississippian strata of the Central Appalachian Basin, USA

1. Bashkirian Pocahontas Fm. 4. Arnsbergian Serpukhovian Pendlean Pennington sequence Brigantian 3. Central Appalachian Basin Asbian Slade sequence Viséan (minus Renfro) Holkerian Warsaw-Salem 2. Ft. Payne sequence Arundian Chadian 1. Ivorian 4. Pennington sequence Borden sequence Tournaisian coastal and shallow marine W E Hastarian Paragon Fm. tidalites, paleosols, coals, marine clastics and minor carbonates Pennington Gp. Sunbury Sh. Mauch Chunk Famennian Berea-Bedford Appalachian Basin subsidence 3. Slade sequence upper part of Pennington Formation at Pound Gap, Kentucky (from KSPG.org) carbonate platform sea level carbonates shallow basin Slade, Newman, Greenbrier Ls. gentle ramp carbonates Mauch Chunk clastics Cane Valley Mbr. Slade Formation (minus Renfro Renfro Member Nada Mbr. On-platform sediments: Ft. Payne sequence (Nada and Renfro here) at Bighill, Kentucky Basin fill: Ft. Payne Formation near Burkesville, Kentucky E W The Borden Formation in east-central. Kentucky From Weir ant others, 1966 The Borden Formation in west-central Kentucky From Keperle, 1977 Cowbell Siltstone E W Nancy Shale From Lewis and Potter, 1978 Borden Delta Front From Matchen and Kammer, 1994 Borden Formation at Bighill, Kentucky Cross section from northeastern Kentucky to eastern W. Virginia Sequences within the Mississippian strata of the Central Appalachian Basin, USA Donald R. CHESNUT*University of Kentucky, 228 MMRB, Lexington, KY 40506, USA; chesnut @ uky.edu Charles MASONMorehead State University, Physical Sciences, 123 Lappin A, Morehead, KY 40351, USA David M. WORKMaine State Museum, 83 State House Station, Augusta, ME 04333, USA The Serpukhovian is represented by the Pennington sequence (herein includes the Pennington Group and Paragon Formation). This third-order sequence is dominated by siliciclastics that thicken along the northeast-striking axis of the Appalachian Basin. Sediment supply kept the basin largely filled as it subsided. The Pennington has numerous paleosols, red and green beds, coastal sandstones, marine shales and carbonates, and thin coals. This heterogeneous unit is certainly influenced by fourth-order eustatic cycles. However, detailed reconstructions are lacking and platform and ramp positions are unknown. The Serpukhovian strata are unconformably overlain by Pennsylvanian coal-bearing siliciclastics. Along the margins of the basin the unconformity is probably a series of amalgamated unconformities of mid-Carboniferous age. Time scale and European substages from Menning and others (2006) W E Appalachian Basin subsidence Late Viséan carbonates of the Slade sequence (herein includes Slade, Newman and Greenbriar formations minus the Renfro) were deposited on the now extensive platform formed by the earlier Borden through Fort Payne cycles. However, this time, the Slade carbonates formed a platform to the west of a Late Viséan northeast-striking basin located in Virginia and eastern West Virginia. Fourth-order cycles within the Slade and its lateral equivalents have been noted, but further systematic studies are needed. From Al-Tawil and Read, 2003 Upper part of Slade Formation at Bighill, Kentucky Fourth-order cycles in the Slade sequence 2. Ft. Payne sequence extensive platform W E Renfro and part Nada Warsaw-Salem Fms. carbonates old Borden delta Ft. Payne Fm. siliciclastics, carbonates, mounds Floyds Knob bed (glauconite) The mixed siliciclastic-carbonate strata of the Early Viséan Fort Payne sequence (herein the Fort Payne, Muldraugh, Renfro, Harrodsburg, Warsaw, Salem and part of the Nada formations) filled in the remnant "Borden" basin with generally southwest prograding strata with discrete beds of shales, siltstones, sandstones, dolostones, “Waulsortian” mounds, and calcareous fenestrate- and crinoidal-biostromes. The thin glauconitic Floyds Knob bed at the base of the sequence traces the underlying Borden delta from basin to delta top and probably represents the maximum flooding surface of the third-order sequence. Up depositional dip, carbonates of the Renfro/Salem/Warsaw/Harrodsburg formations capped the siliciclastic basin fill at later stages. Some fourth-order cycles have been noted in the sequence, but no thorough, basin-scale study has been conducted to correlate these cycles with others around the world. 1. Borden sequence delta platform E sea level W Mary “Borden delta” “delta front” starved basin Pocono siliciclastics Pocono Sunbury black shale Tournaisian siliciclastics of the Borden sequence (herein includes Sunbury, Maury, New Providence, Borden, Cuyahoga, Pocono, Price and Grainger formations) prograded westward from old Acadian highlands in the east. It prograded across the Central Appalachian Basin toward the margin of the basin in Kentucky. The northwest striking Borden Delta Front in Kentucky marks the final delta ramp. To the east of the front, the Borden/Pocono wedge forms a delta platform. To the west of the delta front, thin basinal deposits of the Sunbury (starved basin) and New Providence/Maury (very distal prodelta) are all that represent the Tournaisian deposition in this region. The organic-rich black shales of the Sunbury represent the maximum flooding surface overlying the Famenian clastic wedge (Berea/Bedford). The Borden delta front represents the arrested development of the Borden/Pocono clastic wedge at the end of third-order highstand through lowstand progradation. Discrete packages of siltstone, sandstone, red beds, and limey mounds probably represent the affects of fourth-order cycles, but a basin-scale, systematic litho- and biostratigraphic survey is lacking to differentiate and date many of the cycles. The "fossil" Borden delta front, delta basin and delta platform affected subsequent deposition through mid-Mississippian times. References for Fourth-Order Cycles Al-Tawil, A and Read, J.F., 2003, Late Mississippian (Late Meramecian-Chesterian), glacioeustatic sequence development on an active distal foreland ramp, Kentucky, U.S.A. Permo-Carboniferous Carbonate Platforms and Reefs, Society for Sedimentary Geology (SEPM) Special Publication No. 78 and AAPG Memoir 83, p. 35-55. Khetani, A.B., and Read, J.F., 2002, Sequence development of a mixed carbonate siliciclastic high relief ramp, Mississippian, Kentucky, U.S.A. Journal of Sedimentary Research, v. 72, No. 5, p. 657-672. Krause, R.A., Jr. and Meyer, D.L., 2004, Sequence stratigraphy and depositional dynamics of carbonate buildups and associated facies from the Lower Mississippian Fort Payne Formation of southern Kentucky, U.S.A. Journal of Sedimentary Research, v. 74, p. 831-844. Despite the abundant world-class exposures of Carboniferous strata in the Central Appalachian Basin, the details of biostratigraphy are lacking to correlate all the fourth-order cycles with those of other areas around the world. With extensive exposures of fossiliferous rocks, this area may actually be the best place to examine Mississippian fourth-order cycles in detail. Ongoing biostratigraphic work is being conducted to elucidate these cycles.