File:M98Ch3Fig1.JPG

Chronostratigraphic units (series and stages) currently recognized within the Cambrian and the Lower Ordovician deposits (Sauk megasequence) of the great American carbonate bank and related biostratigraphic units (biozones and biomeres). Laurentian series (Laur. Ser.) and stages for the Cambrian are from Palmer (1998); those for the Ordovician are from Ross et al. (1997) and Loch (2007). The placement of biomere boundaries follows Taylor (2006). Supersequences are those of Palmer (1981). Global series (GL-Se) and stages (GL-Sta) for the Cambrian are from Shergold and Geyer (2003), Babcock et al. (2005, 2007), and Peng et al. (2004); those for the Ordovician are from Webby et al. (2004) as modified in Bergstrom et al. (2006). Abbreviations for defining taxa/criteria for global series and stage boundaries are provided in small rectangles along right margin and are listed below the figure. Genera undergoing taxonomic revision are shown in quotation marks.

From Taylor, John F., John E. Repetski, James D. Loch, and Stephen A. Leslie, 2012, Biostratigraphy and chronostratigraphy of the Cambrian–Ordovician great American carbonate bank, in J. R. Derby, R. D. Fritz, S. A. Longacre, W. A. Morgan, and C. A. Sternbach, eds., The great American carbonate bank: The geology and economic resources of the Cambrian–Ordovician Sauk megasequence of Laurentia: AAPG Memoir 98, p. 15–35.