Mauch Chunk Research Articles

Timing and evolution of the Mississippian sedimentary system on southeastern Laurussia: Evidence from the Appalachian area, U.S.A.

This paper is a synthesis of Mississippian sedimentation on the southeastern, Appalachian margin of Laurussia. The Mississippian stratigraphic framework in the Appalachian area shows a large-scale, three-part, wedge-like, clastic‑carbonate-clastic sequence, which has been interpreted to be a likely flexural response to coeval Neoacadian Orogeny. Using an already established flexural framework and biostratigraphy, we have interpreted the approximate timing of flexural events based on biostratigraphy. These flexural events begin with active deformational loading that initiated rapid subsidence in the Appalachian foreland basin, during which the deeper-water, black Sunbury Shale and equivalents were deposited throughout the basin. Subsequent relaxational loading contributed to basin infilling through the deposition of a deeper-water, clastic succession, manifest as the extensive Cuyahoga-Logan-Borden-Grainger-Price-Rockwell-Pocono deltaic clastic wedge. By the time this clastic wedge had filled the foreland basin, clastic source areas in the orogen had apparently been lowered to the point that shallow seas migrated far eastward across former source areas. This brief period of equilibrium between the basin and source areas resulted in reduced clastic influx at a time when the basin entered subtropical latitudes, setting the stage for widespread carbonate deposition, represented by units like the Newman, Greenbrier, and Slade Limestones. Ensuing, rebound-related uplift, perhaps abetted by incipient, subsurface, Alleghanian thrusting, generated new sediment source areas and accompanying wedges of prograding marginal-marine and terrestrial sediment represented by the Pennington, Mauch Chunk and equivalent units. Marginal-marine sedimentation continued into Early Pennsylvanian time, when a combination of Alleghanian uplift and LPIA lowstand conditions generated a period of widespread, deep erosion that in many places across the Appalachian Basin destroyed substantial parts of the underlying Mississippian succession along the sub-Absaroka or “Mississippian-Pennsylvanian” unconformity. Although the basic Mississippian stratigraphic framework described above for the Appalachian Basin largely appears to be a consequence of Neoacadian flexural responses, major details regarding processes, timing and lithology were apparently controlled by concomitant interactions involving paleoclimate, eustasy, coeval Ouachita tectonism, and possibly early Alleghanian tectonism.

Rock Magnetic Cyclostratigraphy of the Carboniferous Mauch Chunk Formation, Pottsville, PA, United States

A rock magnetic cyclostratigraphy study was conducted on the Carboniferous Mauch Chunk Formation red beds at Pottsville, Pennsylvania to determine if Milankovitch climate forcing could be detected in these terrestrial, fluvial deposits with hematite as the predominant ferromagnetic mineral. This locality was chosen because a robust magnetostratigraphy had already been established for it thus giving an estimate of its sediment accumulation rate. Magnetic susceptibility was measured in the laboratory with a KLY-3s Kappabridge on samples collected every 0.5 m of section for 68 m of section. Magnetic susceptibility measurements were also made in the field using an SM-20 portable susceptibility meter. The time series that resulted were different but yielded very similar power spectra calculated by the multi-taper method. Significant spectral peaks isolated by robust red noise and harmonic f-tests yielded peaks identified to be short eccentricity (125 ka and 95 ka), obliquity (35 ka) and precession (21 and 17.5 ka) in the Carboniferous. Average spectral misfit analysis of these peaks for both the Kappabridge and SM-20 time series gave the identical sediment accumulation rate of 5.69 cm/ka, somewhat slower than the ~9 cm/ka average rate for >250 m of section estimated from magnetostratigraphy and biostratigraphic correlation throughout northeastern North America. Analysis of the low temperature magnetic susceptibility versus temperature curves for a 10 m stratigraphic interval of samples indicates that the ferromagnetic content of the bulk susceptibility appears to be driving the precession- and obliquity-scale bulk susceptibility variations. This observation suggests that climate change in the source area causes more or less erosion of ferromagnetic minerals that are then deposited into a background of paramagnetic clays or diamagnetic quartz sand in the depositional basin. Our study clearly shows that fluvial terrestrial sediments can record astronomically-forced climate change. Our study also indicates that portable susceptibility measurements are a valid way of collecting reconnaissance rock magnetic time series to determine sampling intervals for more detailed studies.

A new lower actinopterygian fish from the Upper Mississippian Bluefield Formation of West Virginia, USA.

The Upper Mississippian Bluefield Formation of the Mauch Chunk Group in southeastern West Virginia is known for its preservation of a variety of invertebrate taxa and early tetrapod trackways, but no lower actinopterygian remains have been formally described from these Carboniferous rocks. Here, the first lower actinopterygian fish is described from the Bluefield Formation of West Virginia. This fish is represented by a nearly complete articulated specimen with a three-dimensional snout and an unobstructed view of the gular and branchiostegal region. This new taxon is defined by a unique set of characters, which include features of the snout, circumorbital series, cheek, and operculo-gular region. These features make this fish different and distinct from previously described Carboniferous fishes. Some of the morphological features of note include the presence of a distinct lacrimal, premaxillary, ventral rostral and dorsal rostral bones, a narrow infraorbital ventral to the orbit, and a large crescent shaped infraorbital that contacts a single dermosphenotic. There is an anteriorly inclined hatchet-shaped preoperculum and six small suborbital bones anterior to the expanded region of this bone that filling the space between the preoperculum, dermosphenotic, and infraorbital. Posterior to the preoperculum, there is a single wedge-shaped dermohyal and a series of three rectangular anteopercular bones. The anteopercular bones extend halfway down the anterior border of the rectangular operculum. A median gular, two pairs of lateral gulars, and at least eight branchiostegal rays are present. The heterocercal caudal fin is deeply cleft and inequilobate. The scales have pectinated posterior margins and bear diagonal ridges of ganoine. The description of this new taxon represents the first actinopterygian and the first vertebrate body fossil described from the Bluefield Formation and the second actinopterygian taxon described from the Mauch Chunk Group in West Virginia.

Upstream controls on incised-valley dimensions and fill: Examples from the Upper Mississippian Mauch Chunk Group, Central Appalachian Basin, USA

Subsurface mapping and facies and architectural element analysis on outcrop, combined with published detrital zircon geochronology and sandstone petrography, are used to reconstruct a source to sink system for two incised-valley fills in the Upper Mississippian Mauch Chunk Group. The lower Stony Gap incised valley is relatively broad and filled with quartzarenite fluvial facies consisting of downstream accreting elements with minimum thicknesses of 6m; cross-sets within elements average 62.5cm thick. The lower Princeton incised valley is relatively narrow and filled with sublitharenite fluvial facies consisting of channel elements that range in thickness from 0.25 to 3.6m; cross-sets within elements average 35cm thick.Quantitative estimates of drainage areas, using regional hydraulic geometry curves for comparable climatic settings, are consistent with order-of-magnitude differences for the lower Stony Gap Sandstone (>700,000km2) and the lower Princeton Formation (<100,000km2). Statistical analysis of the detrital zircon age data reveal that the Stony Gap and Princeton sample populations are not the same and were derived, at least in part, from provenances of different age. Drainage areas are consistent with detrital zircon geochronology and petrographic data and suggest that the lower Stony Gap fluvial sandstone was derived from distal, northern and northwestern cratonic sources including, uniquely, the Archean Superior Province and Proterozoic Penokean-Yavapai-Mazatal provinces, possibly through recycling from older sedimentary rocks. Sediment was dispersed into a NE-SW-oriented, axial drainage system. Inferred channel depths and drainage areas of the lower Stony Gap Sandstone are comparable to the modern Brahmaputra River. In contrast, the younger lower Princeton fluvial sandstone was derived from proximal tectonic highland sources along the eastern margin of the Appalachian Basin that included uplifted older sedimentary rocks and accreted island arc terranes. Sediment was dispersed into a transverse drainage system that was deflected by the existent foreland-basin topography into an axial drainage which is preserved in the study area. Drainage area estimates for the Lower Pennsylvanian Corbin Member in the Appalachian Basin follow the same scaling relationship as the lower Stony Gap Sandstone and lower Princeton Formation incised valleys, where dimensions of incised valleys and their internal fill elements scale to the size of their drainage areas. This study has demonstrated that valley dimensions derived from field and subsurface mapping can be used in conjunction with petrographic data and detrital zircon age spectra to constrain drainage basin area and location, at least to a first order.

Sublethal injuries in non-marine microconchid tubeworms from the Lower Carboniferous of West Virginia, USA

More than 10,000 non-marine microconchid tubeworms (order Tentaculita) from the Lower Carboniferous (Mauch Chunk Group) of West Virginian, USA, have been inspected with respect to the occurrence of specimens having repaired injuries. The inspection showed that only nine specimens bear distinct regenerations of their tubes which constitute only 0.08% of the total specimens. This value, although much lower than that obtained from other encrusting tentaculitoid tubeworms, is very similar to that calculated before for the thousands of Early Devonian planktonic tentaculitids. This clearly indicates that sample size (specimen number) is critical for obtaining the reliable data about the proportion of regenerated vs. unaffected specimens. The sublethal injuries present in these few individuals probably resulted from failed predation, most probably by grazing fishes. However, the repaired injuries only indicate that some individuals survived but do not provide any information about the predation intensity on the group in the given paleoenvironment. Microconchids encrusted a given substrate in large quantities, so grazing fishes may have easily removed the majority of individuals, leaving no trace of predation activity in the Early Carboniferous, non-marine paleoenvironments of what is now West Virginia.

The Geology of Canaan Valley

Abstract Canaan Valley (hereafter, the Valley) is located in the Folded Plateau Physiographic Province of the Appalachian Mountains. The Province features broad, gentle folds and low, structural dips. The Valley lies over the Blackwater Anticline, one of three structures that characterize the high plateau in which the Valley is set. The Anticline plunges northward, creating a broad amphitheater at the Valley's northern end. Southward, the Anticline truncates against a zone of discordance. The cause of the discordance is unknown. South of this zone, the Plateau is more deeply dissected, and the Anticline cannot be traced. In its place, there are three structures that terminate northward against the zone. Local stratigraphy controls the Valley's landscape. Six stratigraphic units—the Pennsylvanian Kanawha Formation, New River Formation, Mississippian Mauch Chunk Formation, Greenbrier Limestone Formation, Price Formation, and Devonian Hampshire Formation—outcrop in the Valley. The ridges in the Valley are su...

Magnetic polarity stratigraphy and palynostratigraphy of the Mississippian-Pennsylvanian boundary interval in eastern North America and the age of the beginning of the Kiaman

Magnetic polarity data from the Maritimes Basin in eastern Canada reveal patterns of magnetic reversal through ∼17 m.y. of late Mississippian and early Pennsylvanian time. We collected samples from three sections on Cape Breton Island, a fourth that extends a section studied previously, and a fifth from a deep cored well on Prince Edward Island. We compared the polarity data from these sections to previous results from lower parts of the Joggins section of eastern Canada. All sections are constrained by new palynological data and collectively span the late Mississippian, Brigantian, Pendleian, and much of the Arnsbergian substages. A major unconformity at the Pennsylvanian-Mississippian boundary makes correlation difficult. The late Mississippian Arnsbergian substage is dominated by normal polarity, whereas the Pendleian and Brigantian are characterized by normal and reversed polarity intervals in about equal proportions. In the United States, the Mississippian-Pennsylvanian boundary is a major hiatus that juxtaposes strata of early Pennsylvanian age on Mississippian strata ranging in age from Brigantian to mid- to late Arnsbergian. Data for the Mauch Chunk Formation in the United States provide polarity reversal patterns for correlative sequences in the Central Appalachian Basin. Field mapping and magnetic polarity data show closely comparable Mississippian-Pennsylvanian relationships in the Maritimes Basin more than 1500 km northeast from the U.S. sections. The eustatic event that coincides with the Mississippian-Pennsylvanian boundary unconformity is late Arnsbergian to Yeadonian in both the central Appalachians and Maritime Basins. Basal Pennsylvanian strata of Yeadonian to Langsettian age on Cape Breton Island reveal normal paleomagnetic polarity through several hundred meters of section. These strata are overlain by a thick section showing only reversed polarity. We believe that this polarity boundary is the base of the Kiaman. An early Langsettian position (ca. 318 Ma) for the base-Kiaman superchron is indicated by these new data. In eastern Nova Scotia and New Brunswick, the sedimentary rocks just above the unconformity are of reversed polarity. It is clear that the sedimentation in the two areas is affected by the unconformity, and no magnetic or palynological correlation is possible. Above the unconformity, only saetosa zone sediments are present.

High-density bioturbated sandstones in the Mississippian Mauch Chunk Formation, eastern Pennsylvania, USA: Implications for continental ecospace exploitation

Continental communities represented by complex, rapidly evolving invertebrate ecosystems first appeared during the Early Palaeozoic Era and are recorded in surface and subsurface bioturbation. The Mississippian-age Mauch Chunk Formation contains several high-density bioturbated, fine-grained sandstones that are preserved as erosively based fluvial channel fills. Several of these channel sandstone bodies are almost completely homogenized by subsequent bioturbation throughout their entire thickness, up to a maximum depth of 1.6m.The Mauch Chunk ichnofossil record demonstrates that high-density bioturbation occurred at least 30my prior to the Permian and well before its widespread distribution in the Triassic. Hence, the Late Mississippian high-density bioturbated sandstones demonstrate a much earlier high-density exploitation of the continental subsurface ecospace than previously known.

A most magnificent machine: America adopts the railroad, 1825-1862

Just as the railroad transformed America's economic landscape, it profoundly transfigured its citizens as well. But while there have been many histories of railroads, few have examined the subject as a social and cultural phenomenon. Informed especially by rich research in the nation's newspaper archives, Craig Miner now traces the growth of railroads from their origins in the 1820s to the onset of the Civil War. In this first social history of the early railroads, Miner reveals how ordinary Americans experienced this innovation at the grass roots, from boosters' dreams of get-rich schemes to naysayers' fears of soulless corporations. Drawing on an amazing 400,000 articles from 185 newspapers-plus more than 3,000 books and pamphlets from the era-he documents the initial burst of enthusiasm accompanying early railroading as it took shape in various settings across the country. Miner examines the cultural, economic, and political aspects of this broad and complicated topic while remaining rooted in the local interests of communities. He takes readers back to the days of the Mauch Chunk Railway, a tourist sensation of the mid-1820s, navigates the mixed reactions to trains as Baltimore's city fathers envisioned tracks to the Ohio River, shows how Pennsylvanians wrestled with the efficacy of railroads versus canals, and describes the intense rivalry of cities competing for trade as old transportation patterns were replaced by the new rail technology. Miner samples individual railroads to compare progress across the industry, showing how it became a quintessentially American business-and how the Panic of 1837 significantly slowed the railways as a major engine of growth for many years. He also explores the impact of railroads on different regions, even disproving the backwardness of the South by citing the Central of Georgia as one of the best-managed and most profitable lines in the country. Through this panoramic work, readers will discover just how the benefits of what became the country's first big business triumphed over cultural concerns, though not without considerable controversy along the way. By identifying citizens' hopes and fears sparked by the railroads, A Most Magnificent Machine takes readers down the tracks of progress as it opens a new window on antebellum America.

The Fish Swimming Trace Undichna from the Mississippian Mauch Chunk Formation, Eastern Pennsylvania

Undichna, the swimming trace of fish, was recovered from the middle member of the Mauch Chunk Formation in eastern Pennsylvania in strata of Late Mississippian (Visean) age. These traces represent the only evidence of fish known from the Mauch Chunk Formation and the Carboniferous of Eastern Pennsylvania. The Mauch Chunk Formation in the study area is characterized by an ephemeral fluvial depositional environment that yields a diverse invertebrate ichnoassemblage of the Scoyenia ichnofacies and a tetrapod footprint assemblage dominated by the tracks of temnospondyl amphibians. The Undichna specimens are preserved on fine-grained, mudstone-draped, rippled sandstone. Two specimens, assigned to U. Britannica, consist of pairs of well-defined, narrowly incised, sinusoidal wave traces that are out-of-phase. Two specimens, assigned to U. quina, consist of two pairs of in-phase sinusoidal waves intersected by an additional single wave with a greater amplitude. Two specimens, each composed of a single wave, are assigned to U. unisulca. The slabs of rock with the Undichna traces also preserve tetrapod undertracks assigned to Batrachichnus, Matthewichnus, and Hylopus. This trace fossil association indicates the presence of small fish, some with caudal and/or anal fins and some with pectoral, pelvic, and anal and/or caudal fins, that touched the sediment during periods of intermittent flooding of subaerial surfaces walked upon by early tetrapods. Examples of Undichna from Mississippian or older deposits, especially from a fluvial paleoenvironment, are rare; few have been reported from the Devonian and the Lower Carboniferous.

Large vertebrate burrow from the Upper Mississippian Mauch Chunk Formation, eastern Pennsylvania, USA

A burrow of probable amphibian origin was discovered in the upper member of the Mississippian Mauch Chunk Formation in eastern Pennsylvania. Facies analysis of the upper member indicates that deposition occurred in an ephemeral–braided stream setting. The burrow is housed in a mudstone and is filled by two graded beds of conglomerate to sandstone. It is characterized by a flared opening leading into a narrower slightly helical tunnel that ends in an inflated ovate chamber approximately 51 to 60 cm in diameter with a maximum height of 20 cm. The flared opening is stratigraphically higher than the elevation at the base of the chamber. The tunnel has a semicircular base. The geometries, abrupt angle changes, inflated termination, width-to-height ratios of the terminal chamber, and graded fill indicate that the structure was an open void prior to sedimentation. The geometry and size of this structure are incompatible with known invertebrate burrows and erosional features. Palaeosauropus primaevus, an amphibian footprint ichnotaxon, recovered from the Mauch Chunk Formation, was made by an amphibian of sufficient size to create such a large burrow. This type of burrowing was most likely a response to seasonal droughts as local water sources evaporated.

A new inclination shallowing correction of the Mauch Chunk Formation of Pennsylvania, based on high-field AIR results: Implications for the Carboniferous North American APW path and Pangea reconstructions

A new magnetic anisotropy study was performed on samples of the Lower Carboniferous Mauch Chunk Formation of Pennsylvania. These red beds had been sampled for an inclination shallowing study by Tan and Kodama (2002), however, application of a high-field anisotropy of isothermal remanence magnetization (hf-AIR) technique specifically designed to measure the anisotropy of hematite provides considerably different results from those previously reported. The newly measured fabric has smaller anisotropy (~ 9–17% as opposed to ~ 25–40%) and shows a pronounced ENE–WSW magnetic lineation that is sub-parallel to the trend of the Appalachians and interpretable as a hematite intersection lineation that occurred during local NNW-directed shortening. The measured magnetic fabric yields a new inclination correction with a corrected paleopole that is in better agreement with recently corrected Carboniferous paleopoles than the previously corrected Mauch Chunk paleopole, defining a more consistent APW path. The corrected paleopoles allow calculation of new mean Early (~ 325 Ma) and Late (~ 312 Ma) Carboniferous inclination-corrected paleopoles for North America, which can be compared to coeval, but uncorrected, paleopoles from Gondwana. Results suggest a Pangea B assemblage unless inclination shallowing is considered for Gondwana. Estimating an inclination correction for Gondwana sedimentary rock-derived paleopoles permits a Pangea A-type assemblage at higher southern latitudes than previous reconstructions, which we term Pangea A3.

Amphibian Body Impressions from the Mississippian of Pennsylvania, USA

Temnocorpichnus isaacleai is a new ichnogenus and ichnospecies of temnospondyl amphibian body impression from the Mississippian (Visean) Mauch Chunk Formation of eastern Pennsylvania, United States. The shovel-shaped head, robust limbs, relatively short trunk and smooth integument diagnose the ichnotaxon and readily distinguish it from Hermundurichnus and Sauropleura, the only other named body impressions of Paleozoic tetrapods. Temnocorpichnus is a compound ichnogenus in which the footprint ichnogenus Batrachichnus is a behaviorally distinct component. The temnospondyl identity of Temnocorpichnus adds to the sparse and earliest records of temnspondyls, which are of Visean age. The smooth integument of the ichnogenus does not support the presence of ventral scales or armor in the earliest temnospondyls, but body proportions of the Mauch Chunk body impressions indicate a relatively terrestrial temnospondyl not matched by any taxon now known from bones. Three closely associated impressions of Temnocorpichnus on a single bedding plane suggest some sort of gregarious behavior in Mississippian temnospondyls and may support speculation that internal fertilization and associated courtship behavior evolved independently in one group of amphibians more than 300 million years ago.

The Mississippian Tetrapod Footprint Ichnogenus Palaeosauropus: Extramorphological Variation and Ichnotaxonomy

Palaeosauropus primaevus is a tetrapod footprint ichnotaxon first described from the Upper Mississippian (Visean) Mauch Chunk Formation near Pottsville, Pennsylvania, United States. Our relocation of the type locality and stratigraphic horizon of P. primaevus, a long-available but unstudied collection of tetrapod footprints from these strata, and our new collections allow a much fuller characterization of this ichnotaxon and the range of extramorphological variation encompassed by it. P. primaevus is characterized as the footprints of a quadruped with a pentadactyl pes and a tetradactyl manus, in which the pes frequently oversteps the manus and with which tail drags are common. In the manus, all digits are relatively broad and have rounded tips, digit III is longest, and digit IV is more widely separated from digit III than the other digits are from each other. The pes has five digits that are also wide and blunt-tipped, digit IV is longest, and digit V projects nearly laterally. P. primaevus is the track of a relatively large temnospondyl (∼400 mm gleno-acetabular length) and documents the Mississippian presence of such large amphibians long before their body fossil record. Palaeosauropus also occurs in Mississippian strata in Indiana and is distinguished from the geologically younger but similar temnospondyl footprint ichnogenus Limnopus by its relatively narrower manus and pes that lack broad and rounded sole impressions.

Invertebrate trace fossils in semi-arid to arid braided-ephemeral-river deposits of the Mississippian middle member of the Mauch Chunk Formation, eastern Pennsylvania, USA

The rapid diversification of terrestrial ecosystems was initiated in the Silurian and subsequently continued through the Mississippian. Detailed collecting of the middle member of the Mississippian Mauch Chunk Formation in eastern Pennsylvania has yielded a number of important vertebrate and invertebrate trace fossils, indicating the presence of a significant terrestrial biotic diversity during the Early Carboniferous. This report illustrates the diverse invertebrate trace fossil assemblage associated with the ephemeral-river systems of the Mauch Chunk. The Mauch Chunk invertebrate ichnoassemblage consists of backfilled burrows of deposit feeders, both meniscate ( Taenidium) and non-meniscate ( Planolites) that typically cross-cut bedding; arthropod trackways ( Diplichnites, Diplopodichnus, Stiaria, Kouphichnium and Stialla); striated trails ( Cruziana) and resting traces ( Rusophycus); and surface or shallow subsurface grazing trails or burrows ( Gordia). Tetrapod footprints, mostly made by temnospondyl amphibians, are also part of this ichnoassemblage. The Mauch Chunk invertebrate ichnoassemblage corresponds well to the Scoyenia ichnofacies in consisting of simple burrows, trackways, striate and bilobate trails and pits and simple meniscate burrows. Typically, trace fossils of the Scoyenia ichnofacies indicate opportunistic behaviors in subaerial environments that are temporarily or periodically inundated. Indeed, the palaeoenvironmental setting of these traces is a semi-arid to possibly arid, braided-ephemeral-river system with extensive overbank deposits. The invertebrate traces were developed both as infaunal burrows in the tops and within channel sandstones and as surface and grazing traces on in-channel mudstone-draped bedforms and in proximal overbank deposits. The in-channel mudstone-draped bedforms display both vertebrate and invertebrate trace fossils. The Mauch Chunk invertebrate ichnofossil assemblage resembles other Devonian through Triassic ichnoassemblages from ephemeral fluvial red beds, confirming that the terrestrial invertebrate fauna had already fully colonized fluvial environments by Mississippian time. Furthermore, the development of the Scoyenia ichnoguild in the Mauch Chunk Formation, in the form of abundant traces of deposit feeders of a shallow to intermediate depth infauna (esp. Taenidium), is unusually early, when compared to the previously known Palaeozoic record.

X-ray CT scan as an aid to identification and description of a new bivalve species (Mollusca) from the Mississippian Bluefield Formation, Southeastern West Virginia

X-ray CT scans at two different energies of three articulated specimens ofSpathelopsis oakvalensisn. sp., a bivalve from the Bluefield Formation of the Mauch Chunk Group (Mississippian, Chesterian) from southeastern West Virginia, permitted observation and description of poorly known internal features of the shell, resulting in a reversal of the shell orientation alleged by past authors and concomitant reassignment of this problematic genus to the palaeotaxodont family Nuculanidae Adams and Adams. Distinctive posterior and anterior gapes inSpathelopsissuggest separation of inhalant and exhalant water streams, a characteristic associated with derived but not primitive palaeotaxodonts.

Isaac Lea's Palaeosauropus (= “Sauropus”) primaevus: A Review of His Discovery

In 1849, Isaac Lea named Sauropus primaevus for footprints from Mount Carbon, Pennsylvania, USA, then the oldest fossil vertebrate footprints reported. In 1902, O. P. Hay constructed a new ichnogenus Palaeosauropus for this ichnospecies. Palaeosauropus has been one of the most frequently reported Mississippian footprint ichnogenera in North America and remains a valid ichnotaxon. The holotype of Palaeosauropus (= “Sauropus”) primaevus (referred to as P. primaevus), consisting of a single manus/pes pair, is described and illustrated in Lea (1853) and is housed at the Academy of Natural Sciences in Philadelphia, Pennsylvania (ANS9752). Lea's large specimen of P. primaevus (approximately 86 cm by 53 cm), that included a trackway of six manus/pes pairs, described and illustrated in 1853 and 1855, was a combination of ANS9752 and a second specimen represented by a plaster cast housed at the National Museum of Natural History (USNM487148). Historical documents and examination of the Mauch Chunk Formation at Mount Carbon, Pennsylvania, enabled the identification of Lea's tracksite, originally reported to be a few hundred feet (about 75 m) from the former Mount Carbon Hotel. Our forensic evidence indicates the type locality for P. primaevus is approximately 90 m south from the southwest corner of Centre and Main Streets in Mount Carbon, Pennsylvania, with geographical coordinates of N 40° 40' 25.7”, W 76° 11' 14.9”. The type locality is within the middle member of the Mauch Chunk Formation, a fluvial sequence of late Mississippian (Visean) Age.

Simplification of the anisotropy-based inclination correction technique for magnetite- and haematite-bearing rocks: a case study for the Carboniferous Glenshaw and Mauch Chunk Formations, North America

SUMMARY An anisotropy-based inclination correction was applied to the Carboniferous Glenshaw Formation from southwestern Pennsylvania. A combination of low-temperature thermal demagnetization followed by alternating field demagnetization isolated a palaeomagnetic remanence direction similar to that previously reported for these rocks. The inclination correction was conducted by fitting the samples’ anisotropy of anhysteretic remanence (AAR) to the theoretical correction curves for a magnetite remanence that yielded a remanence individual magnetic particle anisotropy, the aγ factor, equal to 1.86. Direct measurement of individual particle anisotropy in magnetic grain extracts, yielded an aγ value of 2 in good agreement with the curve fitting technique. The inclination-corrected formation mean directions for these two a factors were statistically indistinguishable. This result shows that curve fitting is an easier, but accurate, method of applying an anisotropy-based inclination correction than direct measurement of the individual grain anisotropy in magnetic grain extracts. The corrected Glendale Formation magnetite-based palaeopole is very similar to haematite-based palaeopoles from the Carboniferous Canadian Maritimes. A new technique is described that extracts the detrital haematite grains from red sedimentary rocks. The measured haematite aγ factors from the Carboniferous Mauch Chunk and Cretaceous Kapusaliang Formations yield values consistent with susceptibility individual particle anisotropies, aχ , determined previously by curve fitting techniques, extending the use of curve fitting for individual particle anisotropy determination to haematite-bearing rocks. However, the corrected Mauch Chunk Formation palaeopole is significantly different from the corrected Glendale Formation palaeopole, calling the accuracy of the Mauch Chunk palaeopole into question. Tectonic strain during folding may have added to the compaction strain in the rocks, leading to an overcorrection of the inclination. A new, inclination-corrected palaeopole for the North American Carboniferous is reported for the Glenshaw Formation at 28.6uN, 119.9uE.

Biostratigraphy of crinoids from the Wymps Gap member of the Greenbrier Formation (Mississippian, Chesterian) in northern West Virginia

Crowns of four crinoid species, Talarocrinus planus Weller, 1920, Phacelocrinus longidactylus (McChesney, 1860), Ampelocrinus mundus? Kirk, 1942, and Phanocrinus maniformis (Yandell and Shumard, 1847) are reported from the limestones of the Wymps Gap Member of the Greenbrier Formation in northern West Virginia. Collectively these species indicate an early Chesterian age for the Wymps Gap Member, with the occurrence of T. planus indicating correlation with the Ridenhower (Paint Creek) Formation of the Illinois Basin. A review of the 17 species currently placed in Talarocrinus suggests that the Talarocrinus zone ranges no higher than the Ridenhower Formation in the Upper Gnathodus bilineatus conodont zone of the late Visean. The new occurrence of A. mundus extends its range upwards from the Genevievian substage of the Chesterian.Previous studies have used sequence stratigraphy to correlate the Wymps Gap Member with the lower part of the Union Limestone Formation of the Greenbrier Group in southern West Virginia, which in turn has been correlated with the Ridenhower Formation. The occurrence of T. planus in the Wymps Gap Member provides independent confirmation of the correlations based on sequence stratigraphy between the Appalachian and Illinois basins. Correlation of the overlying Reynolds Member of the Mauch Chunk Formation with the Glen Dean Formation of the Illinois Basin suggests a significant unconformity between the Greenbrier Formation and Mauch Chunk Formation in northern West Virginia.

Biostratigraphy of crinoids from the Wymps Gap member of the Greenbrier Formation (Mississippian, Chesterian) in northern West Virginia

Crowns of four crinoid species, Talarocrinus planus Weller, 1920, Phacelocrinus longidactylus (McChesney, 1860), Ampelocrinus mundus? Kirk, 1942, and Phanocrinus maniformis (Yandell and Shumard, 1847) are reported from the limestones of the Wymps Gap Member of the Greenbrier Formation in northern West Virginia. Collectively these species indicate an early Chesterian age for the Wymps Gap Member, with the occurrence of T. planus indicating correlation with the Ridenhower (Paint Creek) Formation of the Illinois Basin. A review of the 17 species currently placed in Talarocrinus suggests that the Talarocrinus zone ranges no higher than the Ridenhower Formation in the Upper Gnathodus bilineatus conodont zone of the late Visean. The new occurrence of A. mundus extends its range upwards from the Genevievian substage of the Chesterian. Previous studies have used sequence stratigraphy to correlate the Wymps Gap Member with the lower part of the Union Limestone Formation of the Greenbrier Group in southern West Virginia, which in turn has been correlated with the Ridenhower Formation. The occurrence of T. planus in the Wymps Gap Member provides independent confirmation of the correlations based on sequence stratigraphy between the Appalachian and Illinois basins. Correlation of the overlying Reynolds Member of the Mauch Chunk Formation with the Glen Dean Formation of the Illinois Basin suggests a significant unconformity between the Greenbrier Formation and Mauch Chunk Formation in northern West Virginia.