Research Article| May 01, 2004 The effectiveness of the Paleoproterozoic biological pump: A δ13C gradient from platform carbonates of the Pethei Group (Great Slave Lake Supergroup, NWT) R.M. Hotinski; R.M. Hotinski 1Department of Geosciences and NASA Astrobiology Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA Search for other works by this author on: GSW Google Scholar L.R. Kump; L.R. Kump 1Department of Geosciences and NASA Astrobiology Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA Search for other works by this author on: GSW Google Scholar M.A. Arthur M.A. Arthur 1Department of Geosciences and NASA Astrobiology Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA Search for other works by this author on: GSW Google Scholar Author and Article Information R.M. Hotinski 1Department of Geosciences and NASA Astrobiology Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA L.R. Kump 1Department of Geosciences and NASA Astrobiology Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA M.A. Arthur 1Department of Geosciences and NASA Astrobiology Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA Publisher: Geological Society of America Received: 09 Oct 2002 Revision Received: 09 Jul 2003 Accepted: 23 Aug 2003 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2004) 116 (5-6): 539–554. https://doi.org/10.1130/B25272.1 Article history Received: 09 Oct 2002 Revision Received: 09 Jul 2003 Accepted: 23 Aug 2003 First Online: 02 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 R.M. Hotinski, L.R. Kump, M.A. Arthur; The effectiveness of the Paleoproterozoic biological pump: A δ13C gradient from platform carbonates of the Pethei Group (Great Slave Lake Supergroup, NWT). GSA Bulletin 2004;; 116 (5-6): 539–554. doi: https://doi.org/10.1130/B25272.1 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 Samples of carbonate cements collected along a depth transect of the Pethei Platform, a 1.9 Ga stromatolitic reef, reveal a small (∼0.5‰) carbon isotope gradient between shallow and basinal facies. The magnitude of this gradient would conventionally be interpreted as indicating low export of organic matter from ocean surface waters, but steady-state simulations using a two-box model of the Paleoproterozoic ocean suggest that the small carbon isotope gradient could instead be due to high partial pressures of carbon dioxide in the Paleoproterozoic atmosphere, which would increase the ocean's dissolved inorganic carbon content and damp the effects of biological pumping. If the Paleoproterozoic atmosphere were indeed enriched in atmospheric CO2 in compensation for a less luminous Sun, these results indicate that the planktonic biota was a significant component of the Precambrian global carbon and nutrient cycles, affecting if not regulating (as today) the composition of both surface and deep ocean waters. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.