The Colorado Plateau Coring Project (CPCP): A Continuous Cored Record of Triassic Continental Environmental Change in Western North America

Wednesday, 17 December 2014
Paul E Olsen1, John W Geissman2, George E Gehrels3, Randall B Irmis4, Dennis V Kent1,5, Roland Mundil6, William Parker7, Jingeng Sha8, Roberto S Molina-Garza9, Wolfram Kuerschner10, Gerhard H Bachmann11, Morgan F Schaller12, Natalia V Zakharova1 and Matthew Colbert13, (1)Lamont -Doherty Earth Observatory, Palisades, NY, United States, (2)University of Texas at Dallas, Dallas, TX, United States, (3)University of Arizona, Tucson, AZ, United States, (4)Natural History Museum of Utah, Salt Lake City, UT, United States, (5)Rutgers University, Earth & Planetary Sciences, Piscataway, NJ, United States, (6)Berkeley Geochronology Ctr, Berkeley, CA, United States, (7)Petrified Forest National Park, Petrified Forest, AZ, United States, (8)Nanjing Institute of Geology and Palaeontology, State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing, China, (9)Universidad Nacional Autonoma de Mexico, Mexico City, Mexico, (10)University of Oslo, Department of Geosciences, Oslo, Norway, (11)Martin-Luther-Universität Halle-Wittenberg, Institut für Geowissenschaften, Halle, Germany, (12)Rutgers University, Piscataway, NJ, United States, (13)University of Texas at Austin, University of Texas High Resolution X-ray CT Facility Department of Geological Sciences, Jackson School of Geosciences, Austin, TX, United States
The Triassic Period (251.9-201.3 Ma) is bound by two of the Earth’s largest mass extinctions, suffered several giant bolide impacts and eruption of 3 large igneous provinces, and witnessed evolution of the main components of modern tetrapod communities, and yet has sparse geochronological calibration. To bridge this gap, NSF- and ICDP-funded coring of Phase 1 of the CPCP finished in 12/2013 with the recovery of two major cores (1A, 518m and 2B, 253m; 31km apart) from opposites sides of Petrified Forest National Park spanning nearly the entire Triassic sequence (Chinle & Moenkopi fms) with many U-Pb datable levels (1,2,3) and a recoverable paleomagnetic polarity record (4). The cores will provide a U-Pb and paleomagnetic exportable time scale and sedimentary and geochemical proxies with undoubted superposition testing the motivating hypotheses of: 1) the accuracy of orbitally-paced cyclicity of the Newark APTS (5); 2) apparent climate trends as a function of drift through climate belts (6) and atmospheric CO2 (7); 3) the temporal link between the mid-Late Triassic biotic turnover and the ~100 km Manicouagan impact (1); and 4) the delayed ecological dominance of dinosaurs coupled to climate-driven provinciality (1,8). For orientation, the cores were drilled using a azimuth-tracking device, deviated 30° and 15° from vertical to the SE and S, and CT-scanned. The unprecedented sedimentological and stratigraphic detail visible in the CT-scans, and geophysical logs, plus the ~100% recovery promises successful tests of the motivating hypotheses and provide a superbly detailed reference section for this key episode in Earth system history.

1, Irmis+,2011, EPSL 309:258; 2, Ramazani+, 2011, GSA Bull. 123:2142; 3, Ramazani+, 2014, AJS 314:981; 4, Steiner & Lucas, 2000, JGR B 105:25791; 5, Kent & Olsen, 1999, JGR 104(B6):12831-12841; 6, Kent and Tauxe, 2005, Science 307:240–244; 7, Schaller+, 2012, EPSL 323-324:27–39; 8, Kent +, 2014, PNAS 111:7958–7963.