The earliest Cambrian record of animals and ocean geochemical change

Abstract

Research Article| November 01, 2010 The earliest Cambrian record of animals and ocean geochemical change Adam C. Maloof; Adam C. Maloof † 1Department of Geosciences, Princeton University, Guyot Hall, Washington Road, Princeton, New Jersey 08544, USA †E-mail: [e-mail] Search for other works by this author on: GSW Google Scholar Susannah M. Porter; Susannah M. Porter 2Department of Earth Science, University of California, Santa Barbara, California 93106, USA Search for other works by this author on: GSW Google Scholar John L. Moore; John L. Moore 2Department of Earth Science, University of California, Santa Barbara, California 93106, USA Search for other works by this author on: GSW Google Scholar Frank Ö. Dudás; Frank Ö. Dudás 3Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar Samuel A. Bowring; Samuel A. Bowring 3Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar John A. Higgins; John A. Higgins 1Department of Geosciences, Princeton University, Guyot Hall, Washington Road, Princeton, New Jersey 08544, USA Search for other works by this author on: GSW Google Scholar David A. Fike; David A. Fike 4Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri 63130, USA Search for other works by this author on: GSW Google Scholar Michael P. Eddy Michael P. Eddy 1Department of Geosciences, Princeton University, Guyot Hall, Washington Road, Princeton, New Jersey 08544, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Adam C. Maloof † 1Department of Geosciences, Princeton University, Guyot Hall, Washington Road, Princeton, New Jersey 08544, USA Susannah M. Porter 2Department of Earth Science, University of California, Santa Barbara, California 93106, USA John L. Moore 2Department of Earth Science, University of California, Santa Barbara, California 93106, USA Frank Ö. Dudás 3Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Samuel A. Bowring 3Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA John A. Higgins 1Department of Geosciences, Princeton University, Guyot Hall, Washington Road, Princeton, New Jersey 08544, USA David A. Fike 4Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri 63130, USA Michael P. Eddy 1Department of Geosciences, Princeton University, Guyot Hall, Washington Road, Princeton, New Jersey 08544, USA †E-mail: [e-mail] Publisher: Geological Society of America Received: 04 Jun 2010 Accepted: 03 Aug 2010 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2010 Geological Society of America GSA Bulletin (2010) 122 (11-12): 1731–1774. https://doi.org/10.1130/B30346.1 Article history Received: 04 Jun 2010 Accepted: 03 Aug 2010 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Adam C. Maloof, Susannah M. Porter, John L. Moore, Frank Ö. Dudás, Samuel A. Bowring, John A. Higgins, David A. Fike, Michael P. Eddy; The earliest Cambrian record of animals and ocean geochemical change. GSA Bulletin 2010;; 122 (11-12): 1731–1774. doi: https://doi.org/10.1130/B30346.1 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 SocietyGSA Bulletin Search Advanced Search Abstract The Cambrian diversification of animals was long thought to have begun with an explosive phase at the start of the Tommotian Age. Recent stratigraphic discoveries, however, suggest that many taxa appeared in the older Nemakit-Daldynian Age, and that the diversification was more gradual. We map lowest Cambrian (Nemakit-Daldynian through Tommotian) records of δ13CCaCO3 variability from Siberia, Mongolia, and China onto a Moroccan U/Pb–δ13CCaCO3 age model constrained by five U/Pb ages from interbedded volcanic ashes. The δ13CCaCO3 correlations ignore fossil tie points, so we assume synchroneity in δ13C trends rather than synchroneity in first appearances of animal taxa. We present new δ13Corg, 87Sr/86Sr, uranium, and vanadium data from the same carbonate samples that define the Moroccan δ13CCaCO3 curve. The result is a new absolute time line for first appearances of skeletal animals and for changes in the carbon, strontium, and redox chemistry of the ocean during the Nemakit-Daldynian and Tommotian ages at the beginning of the Cambrian. The time line suggests that the diversification of skeletal animals began early in the Nemakit-Daldynian, with much of the diversity appearing by the middle of the age. Fossil first appearances occurred in three pulses, with a small pulse in the earliest Nemakit-Daldynian (ca. 540–538 Ma), a larger pulse in the mid- to late Nemakit-Daldynian (ca. 534–530 Ma), and a moderate pulse in the Tommotian (ca. 524–522 Ma). These pulses are associated with rapid reorganizations of the carbon cycle, and are superimposed on long-term increases in sea level and the hydrothermal flux of Sr. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.