Testing the limits of chronostratigraphic resolution in the Appalachian Basin, Late Devonian (middle Frasnian), eastern North America: New U-Pb zircon dates for the Belpre Tephra suite

2016 ◽  
Vol 128 (11-12) ◽  
pp. 1813-1821 ◽  
Author(s):  
Amanda Lanik ◽  
D. Jeffrey Over ◽  
Mark Schmitz ◽  
William T. Kirchgasser
1987 ◽  
Vol 61 (4) ◽  
pp. 750-757 ◽  
Author(s):  
George C. Mcintosh

Two recently collected specimens of Bogotacrinus scheibei Schmidt, 1937, from the Devonian (Emsian–Eifelian) Floresta Formation of Colombia reveal that Bogotacrinus is a dicyclic camerate crinoid genus closely related to Pterinocrinus Goldring, 1923 (Lower–Upper Devonian of eastern North America and western Europe), and Ampurocrinus McIntosh, 1981 (Lower Devonian of Bolivia). The new diplobathrid camerate crinoid family Pterinocrinidae, characterized by species with low conical dicyclic cups and rami composed of compound, bipinnulate brachials, is herein proposed to accommodate these three genera. This family originated in western Europe and migrated into the Malvinokaffric and southern Eastern Americas Realms during the Early Devonian and into the northeastern Appalachian Basin by the Late Devonian.


2008 ◽  
Vol 82 (6) ◽  
pp. 1150-1160
Author(s):  
Judith Nagel-Myers ◽  
Michael R. W. Amler ◽  
R. Thomas Becker

Bivalves from the Late Devonian pelagic or Hercynian Facies of classical regions such as eastern North America and Europe have not been investigated for almost a century.A group of small, radially ribbed bivalves frequently occurs in association with ammonoids and conodonts in pelagic cephalopod limestones and shales of the latest Frasnian and early Famennian. These bivalves have traditionally been assigned to the Late Silurian genus Praecardium Barrande, 1881. Re-studying the types of the Late Devonian taxa, Cardium? vetustum Hall, 1843, Cardiola duplicata Münster, 1840, Praecardium clymeniae Beushausen, 1895, Praecardium melletes Clarke, 1904, and Praecardium multicostatum Clarke, 1904 shows that they differ significantly from Praecardium.As a result, two new genera, Vetupraeca n. gen. and Mucopraeca n. gen, are established. Furthermore, neotypes are designated for Cardiola nehdensis, Kayser, 1873 and Vetupraeca clymeniae (Beushausen, 1895), and lectotypes are chosen for Mucopraeca multicostata (Clarke, 1904) and Vetupraeca duplicata (Münster, 1840). These bivalve taxa were widely distributed in the subtropical to tropical, latest Frasnian/early Famennian outer shelf habitats of Laurussia and Gondwana.


1986 ◽  
Vol 60 (3) ◽  
pp. 689-700 ◽  
Author(s):  
Ellis L. Yochelson ◽  
William T. Kirchgasser

This is the first report of styliolines in the Angola Shale Member of the West Falls Formation in western New York. These specimens are of late Frasnian age and are the youngest individuals known from the Appalachian Region. This upward extension of range places the extinction of styliolines in eastern North America more in accord with their time of extinction in Europe. Nowakiids have also been found in the younger Hanover Shale Member, in the upper part of the Java Formation, also of late Frasnian age. These are the youngest known nowakiids from the Appalachians. Within the limits of preservation, the external characters and wall structure of the Angola styliolines are comparable with those of older specimens. The associated rare small annulated nowakiids and homotcenids have a laminated wall structure fundamentally different from that of the styliolines.


1986 ◽  
Vol 60 (1) ◽  
pp. 126-144 ◽  
Author(s):  
M. R. House ◽  
Mackenzie Gordon ◽  
W. J. Hlavin

Three late Devonian ammonoid-bearing levels are described from the area of Cleveland, Ohio. These appear to represent the German Platyclymenia, Clymenia and Wocklumeria Stufen, clear evidence for which has been lacking previously in eastern North America. The lowest level, around the base of the Cleveland Shale, yieldsSporadoceras, Cyrtoclymenia, Platyclymeniaand a new species,Pleuroclymenia(?)ohioense. The middle level, near the top of the Cleveland Shale, bearsCymaclymenia, SporadocerasandPrionoceras. The highest level, just above the base of the Bedford Shale, hasPrionoceras quadripartitum. This species, and a fauna of the basal Bedford, have been located also in the area of Columbus, Ohio. AnEpiwocklumeria(?) sp. is recorded from Indiana. Attention is drawn to the international importance of the late Famennian and Lower Carboniferous ammonoid sequence which can now be recognized in Ohio.


2016 ◽  
Vol 53 (8) ◽  
pp. 837-855 ◽  
Author(s):  
Nikole Bingham-Koslowski ◽  
Cameron Tsujita ◽  
Jisuo Jin ◽  
Karem Azmy

The Kettle Point Formation of southwestern Ontario consists of intervals of organic-rich interlaminated black shale interbedded with organic-poor greyish green mudstones and rare red beds, separated by metre-scale sequences of non-interlaminated black shale. The formation shows a largely consistent background value for the black shales around −20‰ δ34S, punctuated by a substantial positive excursion of ∼32‰ (up to +12.87‰) that coincides with a significant interval of greyish green mudstone and red beds. Lithological and geochemical data indicate that the black shales were deposited during periods of anoxia, with thick intervals of non-interlaminated black shales recording the peak of anoxia, whereas the greyish green mudstones record deposition in more oxygenated environments. Relative water depth is interpreted as the key control on the vertical and lateral distribution of the Kettle Point lithofacies. Interbedded black shales and greyish green mudstones were deposited in relatively shallow waters, where minor, short-lived falls in relative sea level promoted dysoxic to oxic conditions and the deposition of organic-poor lithologies. Non-interlaminated black shales are indicative of substantial rises in relative sea level, resulting in widespread anoxia and the deposition of thicker and more laterally extensive packages of organic-rich sediment. The formation of black shales in relatively shallow waters in southwestern Ontario implies that the extensive deposition of organic-rich sediment across eastern North America during the Late Devonian was a product of widespread anoxia related to restricted circulation in intracratonic and foreland basin depositional centers.


1986 ◽  
Vol 6 (3) ◽  
pp. 227-243 ◽  
Author(s):  
Andrew L. Christenson

Although the interest in shell middens in North America is often traced to reports of the discoveries in Danish kjoekkenmoeddings in the mid-nineteenth century, extensive shell midden studies were already occurring on the East Coast by that time. This article reviews selected examples of this early work done by geologists and naturalists, which served as a foundation for shell midden studies by archaeologists after the Civil War.


Sign in / Sign up

Export Citation Format

Share Document