Mississippian (middle Osagean) ammonoids from the Nada Member of the Borden Formation, Kentucky

Abstract

The borden formation in northeastern Kentucky contains a significant, largely undescribed, Osagean (upper Tournaisian to lower Viséan) ammonoid succession. Lower Osagean strata in the Nancy Member contain a diverse Pericyclus Zone assemblage characterized by Muensteroceras oweni (Hall), M. parallelum (Hall), Kazakhstania colubrella (Morton), Imitoceras ixion (Hall), and Masonoceras kentuckiense Work and Manger. This interval, which ranges into the basal Cowbell Member, was referred to the Muensteroceras oweni Assemblage Zone by Gordon and Mason (1985) and Gordon (1986) and indicates correlation to the lower Ivorian Stage of the Belgian Tournaisian succession. The succeeding middle Osagean interval in the middle and upper part of the Cowbell Member contains Merocanites drostei Collinson and Dzhaprakoceras which presumably represent the lower, or Tournaisian (upper Courceyan or lower Chadian), portion of the Fascipericyclus–Ammonellipsites Zone. An even higher middle Osagean assemblage with Polaricyclus bordenensis new species and Winchelloceras allei (Winchell, 1862) occurs in the upper part of the Nada Member, near the top of the Borden Formation, and is the basis for the current report.

The ammonoids from the Grès du Kahla supérieur of Timimoun (Middle-early Late Tournaisian; Gourara, Algeria)

“…Its similarity to the fauna of the Chouteau Limestone led Miller & Collinson (1951) to assume that the two are time equivalents. Kentucky -Early, middle, and late Osagean ammonoid assemblages (Work & Mason 2003, 2005 show a succession similar to the occurrences in Algeria. The Cave Run Lake fauna (Nancy Member of the Borden Formation; early Osagean) with Kazakhstania, Furnishoceras, and Muensteroceras (Work & Mason 2005) probably represents a time equivalent of the lower assemblage from the Gr s de Kahla sup rieur.…”

The ammonoids from the Dalle àMerocanitesof Timimoun (Late Tournaisian-Early Viséan; Gourara, Algeria)

“…Utah -The assemblage from the Deseret Limestone (Petersen et al 2000) is composed of only two species of Dzhaprakoceras; this makes it difficult to place it within the stratigraphic scheme. Kentucky -Early, middle, and late Osagean ammonoid assemblages (Work & Mason 2003, 2005 show a succession similar to the occurrences in Algeria. Particularly the fauna from the New Providence Shale (late Osagean) with Polaricyclus, Winchelloceras, and Michiganites (Work & Mason 2004) may represent a time equivalent of the assemblage from the Dalle Merocanites.…”

The ammonoids from the Argiles de Teguentour of Oued Temertasset (early Late Tournaisian; Mouydir, Algeria)

“…The Rockford fauna is composed of the genera Imitoceras, Gattendorfia, Prodromites, Muensteroceras, and Protocanites. Kentucky -Of the three Osagean ammonoid assemblages (Work & Mason 2003, 2005, it is particularly the Nada Member of the Borden Formation that is similar to the occurrences at Oued Temertasset. The fauna contains Polaricyclus and Winchelloceras (Work & Mason 2003).…”

“…Kentucky -Of the three Osagean ammonoid assemblages (Work & Mason 2003, 2005, it is particularly the Nada Member of the Borden Formation that is similar to the occurrences at Oued Temertasset. The fauna contains Polaricyclus and Winchelloceras (Work & Mason 2003). Ireland -Of the rich ammonoid fauna described by Crick (1899) and Foord (1901Foord ( , 1903, particularly the material from St. Doulagh's (Co. Dublin) which shows a close resemblance with a distinct horizon within the Argiles de Teguentour.…”

“…They are known from the classic occurrences in the Calcaire de Calonne of Belgium (de Koninck 1844Koninck , 1880Delpine 1940), the 'Carboniferous Limestone' of Ireland (Crick 1899;Foord 1901Foord , 1903, and the Rockford Limestone as well as the Marshall Sandstone of the North American Midcontinent (Hall 1860;Miller & Collinson 1951;Miller & Garner 1955). An outstanding site is the Borden Formation of Kentucky, which yielded well-preserved ammonoids from three successive faunal complexes (Work & Mason 2003, 2005.…”