Biostratigraphy and chronostratigraphy of the Cambrian-Ordovician great American carbonate bank

AAPG Memoir
By: , and 



The carbonate strata of the great American carbonate bank (GACB) have been subdivided and correlated with ever-increasing precision and accuracy during the past half century through use of the dominant organisms that evolved on the Laurentian platform through the Cambrian and the Ordovician. Trilobites and conodonts remain the primary groups used for this purpose, although brachiopods, both calcareous and phosphatic, and graptolites are very important in certain facies and intervals. A series of charts show the chronostratigraphic units (series and stages) currently in use for deposits of the GACB and the biostratigraphic units (zones, subzones, and biomeres) whose boundaries delineate them. Older and, in some cases obsolete, stages and faunal units are included in the figures to allow users to relate information from previous publications and/or industry databases to modern units. This chapter also provides a brief discussion on the use of biostratigraphy in the recognition and interregional correlation of supersequence boundaries within the Sauk and Tippecanoe megasequences, and the varied perspectives on the nature of biostratigraphic units and their defining taxa during the past half century. Also included are a concise update on the biomere concept, and an explanation of the biostratigraphic consequences of a profound change in the dynamics of extinction and replacement that occurred on the GACB in the Early Ordovician when the factors responsible for platformwide biomere-type extinctions faded and ultimately disappeared. A final section addresses recent and pending refinements in the genus and species taxonomy of biostratigraphically significant fossil groups, the potential they hold for greatly improved correlation, and the obstacles to be overcome for that potential to be realized.

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Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title Biostratigraphy and chronostratigraphy of the Cambrian-Ordovician great American carbonate bank
Series title AAPG Memoir
DOI 10.1306/13331488M983497
Volume 98
Year Published 2012
Language English
Publisher AAPG
Publisher location Tulsa, OK
Contributing office(s) Eastern Geology and Paleoclimate Science Center
Description 21 p.
Larger Work Type Book
Larger Work Subtype Monograph
Larger Work Title The great American carbonate bank: The geology and economic resources of the Cambrian-Ordovician Sauk megasequence of Laurentia
First page 15
Last page 35
Other Geospatial North America
Online Only (Y/N) N
Additional Online Files (Y/N) N