Three new Upper Cambrian stages for North America

Research Article| February 01, 1985 Three new Upper Cambrian stages for North America Rolf Ludvigsen; Rolf Ludvigsen 1Department of Geology, University of Toronto, Toronto, Ontario M5S 1A1, Canada Search for other works by this author on: GSW Google Scholar Stephen R. Westrop Stephen R. Westrop 1Department of Geology, University of Toronto, Toronto, Ontario M5S 1A1, Canada Search for other works by this author on: GSW Google Scholar Geology (1985) 13 (2): 139–143. https://doi.org/10.1130/0091-7613(1985)132.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Rolf Ludvigsen, Stephen R. Westrop; Three new Upper Cambrian stages for North America. Geology 1985;; 13 (2): 139–143. doi: https://doi.org/10.1130/0091-7613(1985)132.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The existing Upper Cambrian stages for North America are obsolete. Three new stratotype-defined stages are equivalent to, and replace, three successive biomeres: Marjuman Stage (replaces Marjumiid Biomere, lower boundary at base Ptychagnostus atavis Zone), Steptoean Stage (replaces Pterocephaliid Biomere, lower boundary at base Aphelaspis Zone), Sunwaptan Stage (replaces Ptychaspid Biomere, lower boundary at base Irvingella major Subzone). The base of the overlying Ibexian Series is placed at the base of the Eurekia apopsis Subzone. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.