Bangor Limestone Research Articles

Obruchevodid petalodonts (Chondrichthyes, Holocephali) from the Upper Mississippian (Serpukhovian) Bangor Limestone of northern Alabama, U.S.A.

ABSTRACT Undocumented collections and new field studies have revealed a diverse chondrichthyan assemblage within the Upper Mississippian (Serpukhovian/middle-upper Chesterian) Bangor Limestone in northern Alabama, U.S.A. which includes multiple new occurrences of holocephalians. Included in these new records are the first occurrences of Obruchevodidae (Euchondrocephalii, Petalodontiformes) outside of the synchronic Bear Gulch Limestone Member of the Heath Formation in Montana, U.S.A. Isolated teeth from Fissodopsis robustus and Netsepoye hawesi represent the first specimens to provide three-dimensional tooth morphology that is otherwise obscured in the holotypes. Additionally, these specimens represent the first reported occurrences from the southern coast of the subcontinent Laurentia. The significance of these new specimens is discussed in regard to the comparative morphology of Petalodontiformes and the paleobiogeography of Obruchevodidae.

New ctenacanth sharks (Chondrichthyes; Elasmobranchii; Ctenacanthiformes) from the Middle to Late Mississippian of Kentucky and Alabama

ABSTRACT Two new ctenacanthiform sharks representing two families, Ctenacanthidae and Heslerodidae, have been identified from the Middle to Late Mississippian marine sediments from Mammoth Cave National Park, Kentucky, and two Late Mississippian marine horizons in northern Alabama. The ctenacanthid, Troglocladodus trimblei, gen. et sp. nov., is known from isolated teeth from the Middle Mississippian St. Louis Formation and Ste. Genevieve Formation of Mammoth Cave and the Late Mississippian Bangor Limestone of northern Alabama. Troglocladodus gen. nov. is characterized by broad median cusps, pronounced longitudinal cristae, multiple intermediate cusps, and labiolingually shortened tooth bases. The heslerodid, Glikmanius careforum sp. nov., is known from isolated teeth and visceral arches from the Middle Mississippian St. Louis Formation and Ste. Genevieve Formation and the Late Mississippian Haney Formation, a Hartselle Sandstone-equivalent shale interval, and Bangor Limestone. Glikmanius careforum sp. nov. has proportionately distinct teeth among species of Glikmanius, with more robust and shorter cusps. The palatoquadrate of G. careforum has a short palatine ramus, otic process that is dorsoventrally deep and less expanded antero-posteriorly similar to Heslerodus and Dracopristis, and an elongated quadrate process like Heslerodus. The Meckel’s cartilage is less dorsoventrally deep than Dracopristis. These two new ctenacanth taxa add important information on the diversity of Ctenacanthiformes suggesting three major lineages within the order. Ctenacanths have a rich fossil history from the Late Devonian to the Middle Permian evolving a variety of tooth types and small to large body sizes.

A new janassid (Chondrichthyes, Petalodontiformes) from the Late Mississippian of Alabama, USA

ABSTRACT Teeth from the late Mississippian Bangor Limestone, Monteagle Limestone, and Pride Mountain Formation (early to middle Chesterian = late Viséan–early Serpukhovian) of northern Alabama, USA, are designated as Cavusodus whitei, gen. et sp. nov. The species is similar to Cypripediodens cristatus Duffin and Ward, known only from the Eyam Limestone Formation (Mississippian, late Viséan) of Derbyshire, England. Cypripediodens cristatus, the only species of the genus, is distinguished by teeth having an elongate crown, an apical cusp having a nearly circular cross-section, a secondary cusp on the lingual face, and several cristae on the lingual heel. Cavusodus whitei teeth resemble those of Cypripediodens cristatus but differ in lacking the secondary cusp, in having a more labiolingually compressed apical cusp, in possessing more robust lingual cristae, and in possessing a longitudinal groove on the labial face. The genera comprising the Janassidae are reconsidered. It is proposed that only Janassa, Cholodus, and Cypripediodens be retained, in addition to the new genus. urn:lsid:zoobank.org:pub:DB68190C-E9E6-48C7-B5A7-8A72D174CBCE

Revision of the unusual Carboniferous ophiuroidCholaster(Echinodermata) and remarks on skeletal differentiation within the Asterozoa

AbstractNewly discovered, relatively well-preserved specimens ofCholaster whitein. sp. (Ophiuroidea, Echinodermata) are described from a small area of extensive outcrop of the Bangor Limestone (Mississippian, Chesterian) exposed on the edge of Cedar Creek Reservoir in northern Alabama, USA. The only other known species of the genus,C.peculiarisWorthen and Miller, is based on a single specimen exposed in dorsal aspect and collected from strata of similar age from southwestern Illinois. Incomplete preservation of the singleC.peculiarisspecimen limits comparisons, but differences between the two occurrences support separation at the species level.Skeletal remains of both asteroids and ophiuroids are first recognized from Early Ordovician sediments, and representatives of the two classes have retained plesiomorphies or converged morphologically since that time, thereby suggesting important evolutionary potentials and limitations.Cholasteris asteroid-like and unusual among ophiuroids in that the arms are comparatively broad and strap-like, and lateral ossicles are similar to asteroid adambulacrals and marginals, whereas the “vertebrae” (i.e., fused axial pair) and oral frame configurations ofC. whitein. sp. are typical of the Ophiuroidea. The oral frame ofC. peculiarisis unknown.A poorly preserved specimen of the asteroidDelicaster? also was recovered from nearby strata associated with theC. whitein. sp.UUID:http://zoobank.org/e0eea445-58e5-4096-80c1-a65964832ef6

A new cochliodont anterior tooth plate from the Mississippian of Alabama (USA) having implications for the origin of tooth plates from tooth files

BackgroundPaleozoic holocephalian tooth plates are rarely found articulated in their original positions. When they are found isolated, it is difficult to associate the small, anterior tooth plates with the larger, more posterior ones. Tooth plates are presumed to have evolved from fusion of tooth files. However, there is little fossil evidence for this hypothesis.ResultsWe report a tooth plate having nearly perfect bilateral symmetry from the Mississippian (Chesterian Stage) Bangor Limestone of Franklin County, Alabama, USA. The high degree of symmetry suggests that it may have occupied a symphyseal or parasymphyseal position. The tooth plate resembles Deltodopsis? bialveatus St. John and Worthen, 1883, but differs in having a sharp ridge with multiple cusps arranged along the occlusal surface of the presumed labiolingual axis, rather than a relatively smooth occlusal surface. The multicusped shape is suggestive of a fused tooth file. The middle to latest Chesterian (Serpukhovian) age is determined by conodonts found in the same bed.ConclusionThe new tooth plate is interpreted as an anterior tooth plate of a chondrichthyan fish. It is referred to Arcuodus multicuspidatus Itano and Lambert, gen. et sp. nov. Deltodopsis? bialveatus is also referred to Arcuodus.

A biodetrital coral mound complex: Key to early diagenetic processes in the Mississippian Bangor Limestone

The Bangor Limestone is a Mississippian (Chesterian) shallow marine carbonate formation exposed over a large portion of the Interior Low Plateaus province of northern Alabama. It is dominated by oolitic grainstone and skeletal wackestone and packstone, but in one outcrop near Moulton, Alabama, the Bangor contains a five m thick, 25 m wide, oolite-biodetrital mound-tidal flat succession. This sequence is interpreted as a 4th order sea level cycle.

A lone biodetrital mound in the Chesterian (Carboniferous) of Alabama?

A carbonate mound in the Chesterian Bangor Limestone of Lawrence County, Alabama, consists chiefly of packstone and grainstone dominated by echinoderm ossicles and fragments of fenestrate bryozoans. In-situ colonies of the rugose coral Caninia flaccida comprise about 8% of the mound by volume. The exposed portion of the mound is approximately 25 m wide, 1.6 m thick at the thickest point and roughly circular in plan. The mound developed on top of a shallow ooid shoal that had been cemented and stabilised during an earlier episode of sub-aerial exposure. Subsequent flooding of the exposed shoal surface permitted establishment of the mound biota. Lateral and vertical facies relationships suggest that the mound possessed about 45 cm of synoptic relief when fully developed. Rugose corals, fenestrate and ramose bryozoans, stalked echinoderms, and sessile soft-bodied organisms encrusted by foraminifera colonised the shoal, forming a mound. Baffling resulted in deposition of mixed-fossil packstone containing locally derived debris and coated grains from the surrounding sea floor. Strong currents within the mound are indicated by preferred orientation of corals and by coarse, commonly cross-stratified grainstone in channels between neighboring coral colonies. Corals are most abundant on the windward side of the mound, where they account for about 13% of the mound compared to 6–10% in the central part of the mound, and 2–4% on the leeward flank. Biodetrital mounds such as the one described here are uncommon in upper Paleozoic strata and previously unknown in the Bangor Limestone. Of 10 carbonate buildups we examined in the Bangor in Alabama and Tennessee, only one is a biodetrital mound. Two are rugose coral–microbial reefs, one is a coral biostrome, and six are dominated by microbialite. The Bangor shelf, previously interpreted as sedimentologically simple, appears to contain many small mounds of quite varied characteristics. Also, the discovery of a biodetrital mound in the Chesterian of Alabama suggests that there may be more kinds of upper Paleozoic mounds than commonly acknowledged.

Abstract: Facies and Conodont Content of a Condensed Interval: Mississippian (Chesterian) Bangor Limestone, Central Tennessee and North Alabama 

Abstract: Facies and Conodont Content of a Condensed Interval: Mississippian (Chesterian) Bangor Limestone, Central Tennessee and North Alabama 

Sequential filling of a late Paleozoic foreland basin

ABSTRACT Through the use of an extensive data base of geophysical well logs, parasequence-scale subdivisions within a late Paleozoic synorogenic clastic wedge resolve cycles of sequential subsidence of a foreland basin, sediment progradation, subsidence of a carbonate shelf edge, diachronously subsiding discrete depositional centers, and basinwide transgression. Although temporal resolution of biostratigraphic markers is less precise in Paleozoic successions than in younger basins, parasequence-scale subdivisions provide more detailed resolution within marker-defined units in Paleozoic strata. As an example, the late Paleozoic Black Warrior basin in the foreland of the Ouachita thrust belt is filled with a synorogenic clastic wedge, the lower part of which intertongues with the fringe of a cratonic carbonate facies in the distal part of the basin. The stratal geometry of one tongue of the carbonate facies (lower tongue of Bangor Limestone) defines a ramp that grades basinward into a thin black shale. An overlying tongue of the synorogenic clastic wedge (lower tongue of Parkwood Formation) consists of cyclic delta and delta-front deposits, in which parasequences are defined by marine-flooding surfaces above coarsening- and shallowing-upward successions of mudstone and sandstone. Within the lower Parkwood tongue, two genetic stratigraphic sequences (A and B) are defined by parasequence offlap and downlap patterns and are bounded at the tops by basinwide maximum-flooding surfaces. The distribution of parasequences within sequences A and B indicates two cycles of sequential subsidence (deepening) and progradation, suggesting subsidence during thrust advance and progradation during thrust quiescence. Parasequence stacking in sequences A and B also indicates diachronous differential tectonic subsidence of two discrete depositional centers within the basin. The uppermost sequence (C) includes reworked sandstones and an overlying shallow-marine limestone, a vertical succession that reflects no tectonic subsidence, a very minor or null sediment supply, and basinwide transgression. The temporal resolution at parasequence scale significantly improves the resolution of the tectonic history of the thrust belt-foreland basin system.

Paleoautecology and systematic re-evaluation of Camptocrinus alabamensis (Mississippian: Chesterian) from northern Alabama

Camptocrinus alabamensis Strimple and Moore, from the Gasperian (Mississippian: Chesterian) part of the Monteagle Limestone and overlying Bangor Limestone in northern Alabama, is the only species of Camptocrinus known to have more than 10 arms. Camptocrinus alabamensis exhibits morphological features (basals that are taller on their posterior ends than on their anterior ends, flattened primanal, shorter posteriormost secundibrachs on C ray and D ray) indicative of a tightly coiled life position, with most of the stem lying along the sediment. Unlike other coiled crinoids, Camptocrinus alabamensis had a double-folded stem and more than 10 arms, which we interpret to have been compromise solutions to the problems of protection from high current energy and predation pressure coupled with the need to lift the animal into a feeding posture. In addition, C. alabamensis is the only dichocrinid exhibiting highly modified pinnules, which may have been used as rheo/chemosensory organs. Camptocrinus alabamensis was a leeward passive suspension feeder that, in times of danger, could fold in its arms and coil tightly against the sediment.Camptocrinus alabamensis is removed from synonymy with C. cirrifer and the diagnosis of Camptocrinus is modified. Species of the genera Camptocrinus and Neocamptocrinus should be used only for specimens in which calyces are known; therefore, the plethora of stem-species erected over the years should all be assigned to stem genera unless adequate calyx descriptions are available.

Ostracode paleoecology of the Bangor-Pennington transition (Chesterian, Mississippian) in northeastern Alabama

The Pennington Formation (Chesterian, Mississippian) of northeastern Alabama is a regressive, distal lobe of the Pennington/Lee clastic wedge, located on the western flank of the Appalachians in the Tennessee structural salient. The clastic units of the Pennington include sandstone, siltstone, mudstone, clay shale and coal and are genetically related to the effects of progradation. The presence of limestones and dolostones within the southwestwardly prograding and thinning Pennington is due to the lateral equivalency and interfingering relationships of the Pennington with the upper part of the adjacent Bangor Limestone shelf.A highly diverse ostracode fauna as been collected from outcrops along the Pennington-Bangor transition in northeastern Alabama. The most common assemblage of ostracodes is dominated by kirkbyaceans and includes species of Amphissites, Polytylites, Kirkbyella, Kirkbya and Reviya. Bairdiaceans are noteably absent from this assemblage. The Kirkbyacean Assemblage is only found in middle to outer shelf palaeoenvironments where clastic input is high, but where salinity conditions are thought to have been typically marine. In middle to outer shelf limestone-producing palaeoenvironments, a Bairdiacean Assemblage is dominant, although kirkbyaceans are still present.A Sansabellid Assemblage, consisting of kloedenellaceans such as Sansabella, Geisina, Geffenina, Nufferella and Glyptopleura appears to be produced under rapidly changing nearshore, inner shelf conditions, where terrigenous input was often high and palaeosalinities may have been variable or less than normal marine. The Sansabellid Assemblage contains occasional kirkbyaceans, however bairdiaceans are noteably absent. Intermediate assemblages contain elements of the three main assemblages and reflect the transition from the inner to outer shelf.In summary, the ostracode assemblages of the Pennington-Bangor transition in northeast Alabama provide indicators of palaeoenvironmental change during the southwestward progradation of the Pennington deltaic wedge onto the Bangor Limestone shelf. The prime factors resulting in palaeoecological response appear to have been variations in terrigenous input and palaeosalinity.

First report of hexactinellid dictyosponges and other sponges from the Upper Mississippian Bangor Limestone, northwestern Alabama

Dictyosponges from the Chesteran Bangor Limestone document the first known occurrence of these hexactinellids in Mississippian rocks of Alabama and their discovery adds information to the worldwide impoverished record of Lower Carboniferous Porifera. The sponges are generally fragmented and occur in marine, cross-bedded, sandy limestone and sandstone channel-fill lenses that occur up to 12 m above the base of the formation, above the Hartselle Sandstone. The reticulosid dictyosponges Dictyospongia(?) sp., Clathrospongia bangorensis n. sp., Clathrospongia(?) sp. A, Clathrospongia(?) sp. B, Thamnodictya(?) radiata n. sp., and Phragmodictya rugosa n. sp. are described. Previously, the lyssacinosid(?) hexactinellid Pileospongia lopados Rigby, Keyes, and Horowitz, 1979, was described from this region, from the slightly older Chesteran Monteagle Limestone, and its occurrence in the Bangor Limestone is the youngest yet discovered. In addition to the above hexactinellids, the demosponge Belemnospongia parmula Rigby, Keyes, and Horowitz, 1979, is questionably represented by a single impression in fine-grained sandstone of the Bangor Limestone.

Cyclicity in Upper Mississippian Bangor Limestone, Blount County, Alabama: ABSTRACT

Cyclicity in Upper Mississippian Bangor Limestone, Blount County, Alabama: ABSTRACT

Vicariant Distribution of Two Delphinium Species in Southeastern United States

The distribution of two closely related species, Delphinium treleasei Bush ex Davis and D. alabamicum Kral, is correlated with surface exposures of particular geologic formations. Delphinium treleasei is found only in northwestern Arkansas and southwestern Missouri, and its distribution closely follows the exposure of an upper member of the Ordovician Cotter dolomite. Exposures of the Mississippian Bangor limestone in northwestern Alabama provide habitats for populations of D. alabamicum. Not only are the two species similar in morphology; the geologic formations are similar in mineralogy and geologic history. The most likely explanation for the vicariant distribution of these taxa is parallel evolution.

New flexible crinoids from the Bangor Limestone (Mississippian) of Tennessee

New flexible crinoids referable to Taxocrinus Phillips and Onychocrinus Lyon and Casseday are made known from Carboniferous (Mississippian, Chesterian) strata of Tennessee. Taxocrinus strimplei n. sp. and Onychocrinus sp. A are reported from a single locality in the Bangor Limestone in Cumberland County, east-central Tennessee. Specimens of both species are characterized by having fewer numbers of brachials than any species yet referred to either genus. Both the evolutionary development of their brachial series and their stratigraphic position suggest that these species are at or near the end of lineages of these two genera.

Foraminifera, stratigraphy and regional interpretation of the Bangor Limestone in northwestern Georgia

Foraminifera, stratigraphy and regional interpretation of the Bangor Limestone in northwestern Georgia

Chester (Mississippian) Ostracodes from Bangor Formation of Black Warrior Basin, Northern Alabama: ABSTRACT

A previously unreported ostracode fauna is described from the Bangor Limestone in Franklin, Lawrence, and Colbert Counties, Alabama. The Bangor formation is a Chesterian (Mississippian) platformal carbonate sequence. The predominant carbonates are bioclastic and oolitic grainstones to wackestones with less abundant micritic claystones. Intercalated fine clastics are common in the upper and lower parts of the sequence. This study focuses on the bioclastic limestones with interbedded shales of the lower Bangor. The megafaunal associations include crinoid and blastoid pelmatozoans, orthotetid, and spiriferid brachiopids, and both fenestrate and nonfenestrate bryozoans. Solitary rugose corals and trilobites may be locally abundant. Gastropods and bivalves form a consistent but accessory part of the fauna, which indicates a shallow, nearshore shelf environment. A diverse ostracode fauna of variable abundance has been collected from the shaly units and friable limestones. The ostracode fauna indicates shallow, open-marine conditions and is dominated by bairdiaceans, including Bairdia spp. Rectobairdia and Bairdiacypris. Several species of Cavellina, healdia, and Seminolites are also abundant. Palaeocopids present include Coryellina, Kirkbya, and Polytylites. Kloedenellaceans include Beyrichiopsis, Glyptopleura, Glypotpleurina, and .Hypotetragona. Paraparchitaceans are notably more scarce, but specimens of Shishaella have been found. Some sample have a high valve to carapace ratio, suggesting postmortem transport.more » Although diversity is high, numerical abundances can be low. Initial studies suggest the ostracodes have a Mid-Continent affinity, which may indicate that the Appalachians were acting as a barrier to migration of European forms.« less

Karst landforms and drainage basin evolution in the Obey River basin, north-central Tennessee, U.S.A.

An extensive karst landscape is developed on the Mississippian limestones of the dissected western margin of the Cumberland Plateau. Surface streams rising on the clastic rocks of the Cumberland Plateau flow down the escarpment and sink along its slopes at the upper contact of the Bangor Limestone. Some surface channels are continuous across the karst of the lower slopes while others terminate in blind valleys as swallow holes. At the base of the escarpment is an upland surface of doline karst developed in the Monteagle and St. Louis limestones at an elevation of 300–330 m. It consists of 1–5 km 2 shallow blind valleys and uvala-like closed depressions along with many smaller dolines. The internal drainage from the dolines and from the sinking streams is perched on the impermeable Warsaw Formation and emerges as contact springs on the inner gorges of the rivers which have cut deep narrow valleys below the level of the upland surface. Tributary streams to the Wolf, Obey and Roaring rivers (tributaries of the Cumberland River in north-central Tennessee) were analysed by fitting their longitudinal profiles to exponential and logarithmic functions. Linear segments of semilogarithmic plots permitted extrapolating both active streams and underdrained stream channels through the doline karst. The presently active streams extrapolated through the karst emerge at grade with the present-day base-level streams. Underdrained segments of the tributary valleys extrapolate to the upland surface and suggest that dry karst valleys can be interpreted much like river terraces. The development of interior drainage appears to be a much faster process than is the adjustment of the surface drainage.

Paleogeographic relationship of a Mississippian barrier-island and shelf-bar system (Hartselle Sandstone) in Alabama to the Appalachian-Ouachita erogenic belt

A Mississippian clastic facies in the southern United States is within one of several regionally extensive clastic wedges that record the evolution of the Appalachian-Ouachita orogenic belt along the eastern and southern margin of the North American craton. In the eastern fringe of the wedge in Alabama, the Hartselle Sandstone is a northwest-trending linear sandstone along the regional facies boundary between clastic-wedge rocks (Floyd-Parkwood) and carbonate rocks (Monteagle-Bangor) typical of the shallow-marine shelf of the craton. Internal facies distribution in the Hartselle Sandstone defines a depositional system consisting of a northwest-trending barrier-island complex on the southwest and migrating sand bars on a shelf on the northeast. Barrier-island facies include horizontally laminated foreshore sandstone that contains limestone interbeds, as well as crossbedded longshore bar sandstone that contains fossil logs. The shallow shelf was dominated by migration of bars, wave reworking, and deposition of fine sediment from suspension in interbar areas. These processes are indicated by a complex vertical succession of crossbedded sandstones, rippled sandstones, and mudstones. Shelf processes reworked the upper part of the barrier-island sediment during regional southwestward marine transgression that is confirmed by southwestward extent of the Bangor Limestone over the Hartselle Sandstone. The northwest-trending barrier island of the Hartselle indicates sediment supply from the southwest, and that sediment dispersal system suggests uplift at a tectonically active converging continental margin along the Appalachian-Ouachita orogen during the Mississippian.

Ooid Cortices Composed of Neomorphic Pseudospar: Possible Evidence for Ancient Originally Aragonitic Ooids

Cortices of ooids in a bed in the upper part of the Bangor Limestone (Upper Mississippian) in northwestern Georgia are composed of neomorphic pseudospar which is mostly in a mosaic pattern but also occurs as single crystals in crystallographic continuity with nuclei consisting of echinoderm fragments. Locally common are single crystals of neomorphic spar which are shared by cortices of adjoining ooids. A void-filling origin for the calcite in the ooid cortices is ruled out, for the most part, because of good preservation of concentric structure in the ooids. The tentative conclusion is drawn that the cortices of the ooids originated as aragonite and that echinoderm fragments, where present as nuclei of ooids or as uncoated grains adjacent to ooids, strongly influenced the crystallographic orientation of neomorphic calcite in the cortices.