Part A: General Sequence Stratigraphy and Conodont Biostratigraphy (including new species) of the Uppermost Carboniferous (upper Gzhelian) to Lower Permian (lower Artinskian) from the North American Midcontinent

The uppermost Wabaunsee, Admire, Council Grove, and lower Chase Groups of Kansas, Oklahoma, and Nebraska are placed into three third-order depositional sequences: a Gzhelian late-highstand sequence set, a Council Grove transgressive and highstand sequence set, and a Chase transgressive sequence set. Sequences are defined by bounding maximum-exposure surfaces and are placed within the zone of exposure surfaces (typically, stacked paleosols). Conodonts are abundant in open-marine deposits and most marine units have a differing and characteristic faunal make-up. Eleven species are described as new: Streptognathodus binodosus, S. denticulatus, S. elongianus, S. florensis, S. lineatus, S. nevaensis, S. postconstrictus, S. postelongatus, S. robustus, S. translinearis, and S. trimilus

Part B: Conodont Distribution, Systematics, Biostratigraphy, and Sequence Stratigaphy of the Uppermost Carboniferous and Lower Permian (uppermost Wabaunsee, Admire, Council Grove, and lower Chase Groups) from the North American Midcontinent

aximum-marine flooding levels and marine-condensed sections from uppermost Carboniferous and Lower Permian fourth-order (0.1-1 m.y.) depositional sequences of the North American midcontinent reveal a rich stratigraphic succession of species of Streptognathodus and Sweetognathus conodonts that permits high-precision correlation of the Carboniferous-Permian boundary as well as the Asselian-Sakmarian and Sakmarian-Artinskian boundaries. Eleven new species of Streptognathodus are described: Streptognathodus binodosus, S. denticulatus, S. elongianus, S. florensis, S. lineatus, S. nevaensis, S. postconstrictus, S. postelongatus, S. robustus, S. translinearis, and S. trimilus. Seventeen species are redescribed and clarified and include Streptognathodus alius, S. barskovi, S. bellus, S. brownvillensis, S. conjunctus, S. constrictus, S. elongatus, S. farmeri, S. flexuosus, S. fuchengensis, S. fusus, S. invaginatus, S. isolatus, S. longissimus, S. minacutus, S. nodulinearis, and S. wabaunsensis. The correlated level of the Carboniferous-Permian boundary is recognized in the lower part of the Red Eagle Depositional Sequence based on the introduction of Streptognathodus isolatus Chernykh, Ritter, and Wardlaw; Streptognathodus minacutus Barskov and Reimers; Streptognathodus invaginatus Reshetkova and Chernykh; Streptognathodus fuchengensis Zhao; and Streptognathodus nodulinearis Reshetkova and Chernykh. The correlated Carboniferous-Permian boundary occurs in the depositional sequence that represents the maximum-marine highstand of the Council Grove Composite Third Order Sequence. This level represents a significant marine-flooding event that should be correlatable in numerous shelfal sections throughout the world. Although the Asselian-Sakmarian boundary has not been rigorously defined, Sweetognathus merrilli has been informally utilized as a Sakmarian indicator. Due to the ecologically controlled distribution of species of Sweetognathus, we prefer to use a species of Streptognathodus as a defining species. We propose that Streptognathodus barskovi (Kozur) Reshetkova be considered as a potentially defining or ancillary defining species for the Sakmarian Stage. In the North American midcontinent, Streptognathodus barskovi appears in the same depositional sequence with Sweetognathus merrilli in the Eiss (Lower Bader) Depositional Sequence. Historically, Sweetognathus whitei has been used to mark the Sakmarian-Artinskian boundary. In our succession Sweetognathus whitei and Streptognathodus florensis appear in the basal part of the Barneston Depositional Sequence. We suggest that Streptognathodus florensis be further investigated as a possible defining or ancillary defining taxon for the base of the Artinskian Stage. This depositional sequence also forms the maximum-marine highstand of the Chase Third-Order Composite Depositional Sequence suggesting that this level is a significant marine-flooding event that should be widely traceable in numerous shelfal sections

Part A: General Sequence Stratigraphy and Conodont Biostratigraphy (including new species) of the Uppermost Carboniferous (upper Gzhelian) to Lower Permian (lower Artinskian) from the North American Midcontinent

The uppermost Wabaunsee, Admire, Council Grove, and lower Chase Groups of Kansas, Oklahoma, and Nebraska are placed into three third-order depositional sequences: a Gzhelian late-highstand sequence set, a Council Grove transgressive and highstand sequence set, and a Chase transgressive sequence set. Sequences are defined by bounding maximum-exposure surfaces and are placed within the zone of exposure surfaces (typically, stacked paleosols). Conodonts are abundant in open-marine deposits and most marine units have a differing and characteristic faunal make-up. Eleven species are described as new: Streptognathodus binodosus, S. denticulatus, S. elongianus, S. florensis, S. lineatus, S. nevaensis, S. postconstrictus, S. postelongatus, S. robustus, S. translinearis, and S. trimilus

Part B: Conodont Distribution, Systematics, Biostratigraphy, and Sequence Stratigaphy of the Uppermost Carboniferous and Lower Permian (uppermost Wabaunsee, Admire, Council Grove, and lower Chase Groups) from the North American Midcontinent

aximum-marine flooding levels and marine-condensed sections from uppermost Carboniferous and Lower Permian fourth-order (0.1-1 m.y.) depositional sequences of the North American midcontinent reveal a rich stratigraphic succession of species of Streptognathodus and Sweetognathus conodonts that permits high-precision correlation of the Carboniferous-Permian boundary as well as the Asselian-Sakmarian and Sakmarian-Artinskian boundaries. Eleven new species of Streptognathodus are described: Streptognathodus binodosus, S. denticulatus, S. elongianus, S. florensis, S. lineatus, S. nevaensis, S. postconstrictus, S. postelongatus, S. robustus, S. translinearis, and S. trimilus. Seventeen species are redescribed and clarified and include Streptognathodus alius, S. barskovi, S. bellus, S. brownvillensis, S. conjunctus, S. constrictus, S. elongatus, S. farmeri, S. flexuosus, S. fuchengensis, S. fusus, S. invaginatus, S. isolatus, S. longissimus, S. minacutus, S. nodulinearis, and S. wabaunsensis. The correlated level of the Carboniferous-Permian boundary is recognized in the lower part of the Red Eagle Depositional Sequence based on the introduction of Streptognathodus isolatus Chernykh, Ritter, and Wardlaw; Streptognathodus minacutus Barskov and Reimers; Streptognathodus invaginatus Reshetkova and Chernykh; Streptognathodus fuchengensis Zhao; and Streptognathodus nodulinearis Reshetkova and Chernykh. The correlated Carboniferous-Permian boundary occurs in the depositional sequence that represents the maximum-marine highstand of the Council Grove Composite Third Order Sequence. This level represents a significant marine-flooding event that should be correlatable in numerous shelfal sections throughout the world. Although the Asselian-Sakmarian boundary has not been rigorously defined, Sweetognathus merrilli has been informally utilized as a Sakmarian indicator. Due to the ecologically controlled distribution of species of Sweetognathus, we prefer to use a species of Streptognathodus as a defining species. We propose that Streptognathodus barskovi (Kozur) Reshetkova be considered as a potentially defining or ancillary defining species for the Sakmarian Stage. In the North American midcontinent, Streptognathodus barskovi appears in the same depositional sequence with Sweetognathus merrilli in the Eiss (Lower Bader) Depositional Sequence. Historically, Sweetognathus whitei has been used to mark the Sakmarian-Artinskian boundary. In our succession Sweetognathus whitei and Streptognathodus florensis appear in the basal part of the Barneston Depositional Sequence. We suggest that Streptognathodus florensis be further investigated as a possible defining or ancillary defining taxon for the base of the Artinskian Stage. This depositional sequence also forms the maximum-marine highstand of the Chase Third-Order Composite Depositional Sequence suggesting that this level is a significant marine-flooding event that should be widely traceable in numerous shelfal sections

Southeast Nebraska Geology: Field Trip 3

The purpose of this trip is to familiarize you with the latest Pennsylvanian and earliest Permian rocks that are exposed in extreme southeastern Nebraska. You will see eight exposures of these rocks and will have ample opportunity to collect lithologic samples, as well as samples for both macro- and micro-fossils. The stops have been selected to show you examples of several different environments that existed in southeastern Nebraska in the late Paleozoic. These include subaerial deposits with paleosols, nearshore and offshore marine clastic and carbonate sequences. Each stop is covered in detail in the handouts that have been furnished to the trip participants. Subsequent readers will be able to find this information in the several references that are listed at the end of the text. All of the stops will be in Richardson and Pawnee counties (fig. 1)

Biostratigraphy of Middle and Late Pennsylvanian (Desmoinesian-Virgilian) ammonoids

New stratigraphic ranges for genera of Desmoinesian-Virgilian ammonoids are presented, based on analysis of 40,000 specimens collected from over 70 ammonoid-bearing horizons that represent at least 40 successive stratigraphic levels in the North American midcontinent. These range revisions indicate that current generic-level ammonoid zonations are inadequate, especially for correlation of Pennsylvanian series and stage boundaries. Six high-confidence, largely generic-level first-occurrence zones are proposed for the Desmoinesian through Virgilian stages: Wellerites Zone, Eothalassoceras Zone, Pennoceras Zone, Preshumardites Zone, Pseudaktubites Zone, and Shumardites Zone. Fifteen zones of lesser confidence for correlation are also suggested. The Shumarditidae Plummer & Scott, 1937, is emended to include Preshumardites Plummer & Scott, 1937, Pseudaktubites gen. nov. (type species, Preshumardites stainbrooki Plummer & Scott, 1937), and Shumardites Smith, 1903. Early Permian (Sakmarian) species previously assigned to Preshumardites are reassigned to Andrianovia gen. nov. (type species ?Preshumardites sakmarae Ruzhencev, 1938). Aktubites Ruzhencev, 1955, Eoshumardites Popov, 1960, and Parashumardites Ruzhencev, 1939, previously included in the Shumarditidae, are assigned to the new family Parashumarditidae. Eovidrioceras inexpectans gen. nov., sp. nov. is included and is interpreted as the ancestor of the cyclobacean family Vidrioceratidae Plummer & Scott, 1937. The base of the revised Wellerites Zone, defined by the first occurrence of the nominate genus, approximates but does not coincide with the Atokan-Desmoinesian boundary. Recorrelation of the stratigraphic level of the Collinsville, Oklahoma, ammonoid locality from the "Seminole Formation" (basal Missourian) to the Holdenville Formation (upper Desmoinesian), based on lithostratigraphic evidence, effectively places the first occurrence of Eothalassoceras in the upper Desmoinesian. Because Wellerites apparently became extinct before the end of the Desmoinesian, the revised Eothalassoceras Zone is used to represent the upper Desmoinesian. The Middle-Upper Pennsylvanian boundary (Desmoinesian-Missourian boundary) can be recognized by the appearance of Pennoceras, which defines the base of the new Pennoceras Zone. The Pennoceras Zone is an excellent indicator of lower Missourian strata in the northern midcontinent, north-central Texas, the Marathon Uplift, and the Appalachian Basin. The new Preshumardites Zone occupies most of the upper part of the Missourian Stage. The appearance of the ancestral shumarditid Pseudaktubites, which defines the base of the new Pseudaktubites Zone, occurs one cycle below the Missourian-Virgilian boundary, which is currently recognized at the top of the South Bend Limestone Member in eastern Kansas. No recognizable biostratigraphic event coincides with the South Bend Member, thereby resulting in an uncorrelatable chronostratigraphic boundary. The largest changeover in ammonoid faunas takes place at the base of strata containing the upper part of the Pseudaktubites Zone (Pseudaktubites stainbrooki Subzone). The base of the Pseudaktubites stainbrooki Subzone is stratigraphically near the original Missourian-Virgilian boundary. It is recommended that the stratigraphic level containing the base of the Pseudaktubites stainbrooki Subzone be adopted as the official base of the Virgilian Stage. Recognition of the upper subzone of the Pseudaktubites Zone (Pseudaktubites stainbrooki Subzone) within the Colony Creek Shale Member in north-central Texas places the base of the Virgilian within the upper part of the Canyon Group and substantially below the current position at the Canyon-Cisco group boundary. Shumardites, a taxon previously used to mark the base of the Virgilian Stage, appears in early middle Virgilian strata; consequently, the revised Shumardites Zone represents the middle-upper Virgilian interval

Biostratigraphy of Middle and Late Pennsylvanian (Desmoinesian-Virgilian) ammonoids

New stratigraphic ranges for genera of Desmoinesian-Virgilian ammonoids are presented, based on analysis of 40,000 specimens collected from over 70 ammonoid-bearing horizons that represent at least 40 successive stratigraphic levels in the North American midcontinent. These range revisions indicate that current generic-level ammonoid zonations are inadequate, especially for correlation of Pennsylvanian series and stage boundaries. Six high-confidence, largely generic-level first-occurrence zones are proposed for the Desmoinesian through Virgilian stages: Wellerites Zone, Eothalassoceras Zone, Pennoceras Zone, Preshumardites Zone, Pseudaktubites Zone, and Shumardites Zone. Fifteen zones of lesser confidence for correlation are also suggested. The Shumarditidae Plummer & Scott, 1937, is emended to include Preshumardites Plummer & Scott, 1937, Pseudaktubites gen. nov. (type species, Preshumardites stainbrooki Plummer & Scott, 1937), and Shumardites Smith, 1903. Early Permian (Sakmarian) species previously assigned to Preshumardites are reassigned to Andrianovia gen. nov. (type species ?Preshumardites sakmarae Ruzhencev, 1938). Aktubites Ruzhencev, 1955, Eoshumardites Popov, 1960, and Parashumardites Ruzhencev, 1939, previously included in the Shumarditidae, are assigned to the new family Parashumarditidae. Eovidrioceras inexpectans gen. nov., sp. nov. is included and is interpreted as the ancestor of the cyclobacean family Vidrioceratidae Plummer & Scott, 1937. The base of the revised Wellerites Zone, defined by the first occurrence of the nominate genus, approximates but does not coincide with the Atokan-Desmoinesian boundary. Recorrelation of the stratigraphic level of the Collinsville, Oklahoma, ammonoid locality from the "Seminole Formation" (basal Missourian) to the Holdenville Formation (upper Desmoinesian), based on lithostratigraphic evidence, effectively places the first occurrence of Eothalassoceras in the upper Desmoinesian. Because Wellerites apparently became extinct before the end of the Desmoinesian, the revised Eothalassoceras Zone is used to represent the upper Desmoinesian. The Middle-Upper Pennsylvanian boundary (Desmoinesian-Missourian boundary) can be recognized by the appearance of Pennoceras, which defines the base of the new Pennoceras Zone. The Pennoceras Zone is an excellent indicator of lower Missourian strata in the northern midcontinent, north-central Texas, the Marathon Uplift, and the Appalachian Basin. The new Preshumardites Zone occupies most of the upper part of the Missourian Stage. The appearance of the ancestral shumarditid Pseudaktubites, which defines the base of the new Pseudaktubites Zone, occurs one cycle below the Missourian-Virgilian boundary, which is currently recognized at the top of the South Bend Limestone Member in eastern Kansas. No recognizable biostratigraphic event coincides with the South Bend Member, thereby resulting in an uncorrelatable chronostratigraphic boundary. The largest changeover in ammonoid faunas takes place at the base of strata containing the upper part of the Pseudaktubites Zone (Pseudaktubites stainbrooki Subzone). The base of the Pseudaktubites stainbrooki Subzone is stratigraphically near the original Missourian-Virgilian boundary. It is recommended that the stratigraphic level containing the base of the Pseudaktubites stainbrooki Subzone be adopted as the official base of the Virgilian Stage. Recognition of the upper subzone of the Pseudaktubites Zone (Pseudaktubites stainbrooki Subzone) within the Colony Creek Shale Member in north-central Texas places the base of the Virgilian within the upper part of the Canyon Group and substantially below the current position at the Canyon-Cisco group boundary. Shumardites, a taxon previously used to mark the base of the Virgilian Stage, appears in early middle Virgilian strata; consequently, the revised Shumardites Zone represents the middle-upper Virgilian interval