Late Ordovician-Early Silurian acritarch biostratigraphy and taxonomy, Anticosti Island, Québec

Late Ordovician-Early Silurian acritarch biostratigraphy and taxonomy, Anticosti Island, Québec by Susan I. Duffield Download PDF EPUB FB2

The diverse Katian (Late Ordovician) through Llandovery (Early Silurian) crinoid fauna from Anticosti Island is described. Previously, six described Late Ordovician-Early Silurian acritarch biostratigraphy and taxonomy were known; with one now a nomen dubium. It also occurs in the Katian, Vauréal Forma- tion, Québec (Achab, ); Utica and Lorraine formations, Québec (Achab, ); and Late Ordovician, Ellis Bay For- mation, Anticosti Island.

During the Late Ordovician–early Silurian, Anticosti Island and southern Estonia were located on two separate palaeoplates positioned at low latitudes: Laurentia and Baltica, respectively ().Late Ordovician successions of Anticosti Island were deposited on a carbonate ramp at the edge of the Anticosti Basin located on the eastern margin of Laurentia (Barnes, ), while Cited by: A detailed study of Late Ordovician–early Silurian acritarchs (Palaeozoic phytoplankton) from Anticosti Island (Québec, Canada) revealed an unusually high abundance of abnormal forms from the upper Hirnantian carbonate strata (uppermost Ordovician) of the Ellis Bay Formation in the western part of the island (member 6, Spinachitina taugourdeaui chitinozoan Biozone).Cited by:   S.L.

Duffield Late Ordovician—Early Silurian acritarch biostratigraphy and taxonomy, Anticosti Island, Québec [unpublished Ph.D. thesis]. [Ontario (Canada)]: University of Waterloo, p. Google ScholarCited by:   Introduction.

The latest Ordovician Hirnantia brachiopod fauna is a unique phenomenon in the evolution of Palaeozoic benthic faunas, which has received much attention in the last decades. During the latest Ordovician, restructuring of facies patterns commenced in the late Pirgu (end of the Katian) with a diachronous, upward shallowing across by: 7.

A critical review of all available data on acritarch biostratigraphy and diversity dynamics across the Late Ordovician through the early Silurian, permits a better appreciation of the potential of acritarchs for the recognition of the systemic boundary.

Sections from Anticosti Island (Québec, Canada), Algeria, Morocco, and Estonia preserve. The δ U trends at Anticosti Island, Canada, document an abrupt late Hirnantian ∼‰ negative shift continuing through the early Silurian indicating more reducing seawater conditions.

The lack of observed anoxic facies and no covariance among δ U values and other local redox proxies suggests that the δ U trends represent a. The present book, Ordovician of the World, is the proceedings volume for the 11th Symposium on the Ordovician System, sponsored by the Subcommission on Ordovician Stratigraphy of the International Union of Geological Sciences.

Rak LATE ORDOVICIAN-EARLY SILURIAN SELECTIVE EXTINCTION PATTERNS IN LAURENTIA AND THEIR RELATIONSHIP TO .