A 30 Myr record of Late Triassic atmosphericpCO2variation reflects a fundamental control of the carbon cycle by changes in continental weathering

Research Article| May 01, 2015 A 30 Myr record of Late Triassic atmospheric pCO2 variation reflects a fundamental control of the carbon cycle by changes in continental weathering Morgan F. Schaller; Morgan F. Schaller 1Department of Earth and Planetary Sciences, Rutgers University, Piscataway, New Jersey 08854, USA †Current address: Earth and Environmental Science, Rensselaer Polytechnic Institute, Troy, New York 12180, USA; e-mail: schall@rpi.edu. Search for other works by this author on: GSW Google Scholar James D. Wright; James D. Wright 1Department of Earth and Planetary Sciences, Rutgers University, Piscataway, New Jersey 08854, USA Search for other works by this author on: GSW Google Scholar Dennis V. Kent Dennis V. Kent 1Department of Earth and Planetary Sciences, Rutgers University, Piscataway, New Jersey 08854, USA2Lamont Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Morgan F. Schaller †Current address: Earth and Environmental Science, Rensselaer Polytechnic Institute, Troy, New York 12180, USA; e-mail: schall@rpi.edu. 1Department of Earth and Planetary Sciences, Rutgers University, Piscataway, New Jersey 08854, USA James D. Wright 1Department of Earth and Planetary Sciences, Rutgers University, Piscataway, New Jersey 08854, USA Dennis V. Kent 1Department of Earth and Planetary Sciences, Rutgers University, Piscataway, New Jersey 08854, USA2Lamont Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA Publisher: Geological Society of America Received: 05 Apr 2014 Revision Received: 23 Sep 2014 Accepted: 20 Oct 2014 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2014 Geological Society of America GSA Bulletin (2015) 127 (5-6): 661–671. https://doi.org/10.1130/B31107.1 Article history Received: 05 Apr 2014 Revision Received: 23 Sep 2014 Accepted: 20 Oct 2014 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Morgan F. Schaller, James D. Wright, Dennis V. Kent; A 30 Myr record of Late Triassic atmospheric pCO2 variation reflects a fundamental control of the carbon cycle by changes in continental weathering. GSA Bulletin 2015;; 127 (5-6): 661–671. doi: https://doi.org/10.1130/B31107.1 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 We generate a detailed ∼30 Myr record of pCO2 spanning most of the Late Triassic (Carnian-Norian-Rhaetian) to earliest Jurassic (Hettangian), based on stable carbon isotope ratios of soil carbonate and preserved organic matter from paleosols in the eastern North American Newark rift basin. Atmospheric pCO2 was near 4500 ppm in the late Carnian, decreasing to below ∼2000 ppm by the late Rhaetian just before the earliest Jurassic eruption of the Central Atlantic Magmatic Province, which triggered measurable pulses of CO2 outgassing. These data are consistent with published modeling results using the GEOCLIM model, which predict a decrease in pCO2 over the Late Triassic as a result of the progressive increase in continental area subject to the intense weathering regime of the tropical humid belt due to Pangea's northward motion. The finer-scale pCO2 changes we observe may be dependent on the lithology introduced to the tropics, such as the dip to ∼2000 ppm around 212 Ma and its rebound to ∼4000 ppm at 209 Ma, which can be accomplished by introducing a more weatherable subaerial basaltic terrain. These observations indicate that the consumption of CO2 by continental silicate weathering can force long-term changes in pCO2 comparable to those driven by presumed changes in mantle degassing. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.