This study contains a documentation of conodont biofacies deduced from fragments of the shelf margin facies to establish a biostratigraphic zonation and to determine conodont paleoecology of the inner marginal environment through the Arenig interval. Among clasts in the megaconglomerates, local (lower slope derived), foreign (shelf, shelf break, and upper slope derived), and older clasts were distinguished. About 300 conodont samples were collected and processed, mainly from clasts of the three conglomerate horizons. The 12,492 conodont specimens recovered represent 132 different form and multi-element species.
This volume explores geological boundaries in time and space using palynology and micropalaeontology. Boundaries produce distinct signatures in the micropalaeontological record. They can tell us much about the response of biotic systems to environmental change in both marine and terrestrial realms. Different microfossil groups and geological contexts require their own approaches, definitions and considerations of boundaries. The papers here cover the methodology of boundary identification from biostratigraphical, ecological and palaeoenvironmental perspectives.
Selected papers from the August 1988 symposium on the Ordovician System. Authors from the U.K., Canada, Australia, and the U.S. contributed papers on a project to redefine regional chronostratigraphic subdivisions. Papers also cover Ordovician paleontology and biostratigraphy, emphasizing conodonts, graptolites and trilobites. The interrelationships of stratigraphy, eustasy, tectonics, and volcanisms are explored, with particular attention to the Appalachian Orogen. The final section of the volume documents some of the new data and interpretations of Ordovician paleo-oceanography, paleoclimatology, and paleogeography.