Atmospheric Pco2 Perturbations Associated with the Central Atlantic Magmatic Province

Emplacement of the Central Atlantic Magmatic Province 200 million years ago greatly elevated atmospheric carbon dioxide concentrations. The effects of a large igneous province on the concentration of atmospheric carbon dioxide (Pco2) are mostly unknown. In this study, we estimate Pco2 from stable isotopic values of pedogenic carbonates interbedded with volcanics of the Central Atlantic Magmatic Province (CAMP) in the Newark Basin, eastern North America. We find pre-CAMP Pco2 values of ~2000 parts per million (ppm), increasing to ~4400 ppm immediately after the first volcanic unit, followed by a steady decrease toward pre-eruptive levels over the subsequent 300 thousand years, a pattern that is repeated after the second and third flow units. We interpret each Pco2 increase as a direct response to magmatic activity (primary outgassing or contact metamorphism). The systematic decreases in Pco2 after each magmatic episode probably reflect consumption of atmospheric CO2 by weathering of silicates, stimulated by fresh CAMP volcanics.

[1]  R. Sambrotto,et al.  Compound-specific carbon isotopes from Earth’s largest flood basalt eruptions directly linked to the end-Triassic mass extinction , 2010, Proceedings of the National Academy of Sciences.

[2]  Z. Sharp,et al.  Seasonal bias in the formation and stable isotopic composition of pedogenic carbonate in modern soils from central New Mexico, USA , 2009 .

[3]  S. Planke,et al.  Siberian gas venting and the end-Permian environmental crisis , 2008 .

[4]  S. Dworkin,et al.  Pedogenic carbonate isotopes as evidence for extreme climatic events preceding the Triassic-Jurassic boundary: Implications for the biotic crisis? , 2008 .

[5]  V. Masson‐Delmotte,et al.  Target atmospheric CO2: Where should humanity aim? , 2008, 0804.1126.

[6]  L. Nordt,et al.  Continental Sequence Stratigraphy of the Upper Triassic (Norian–Rhaetian) Chinle Strata, Northern New Mexico, U.S.A.: Allocyclic and Autocyclic Origins of Paleosol-Bearing Alluvial Successions , 2007 .

[7]  D. Kent,et al.  Synchrony between the Central Atlantic magmatic province and the Triassic-Jurassic mass-extinction event? , 2007 .

[8]  A. Coe,et al.  The impact of the Central Atlantic Magmatic Province on climate and on the Sr- and Os-isotope evolution of seawater , 2007 .

[9]  T. Thordarson,et al.  Volatile fluxes during flood basalt eruptions and potential effects on the global environment: A Deccan perspective , 2006 .

[10]  S. Dworkin,et al.  Determining terrestrial paleotemperatures using the oxygen isotopic composition of pedogenic carbonate , 2005 .

[11]  L. François,et al.  Basaltic volcanism and mass extinction at the Permo-Triassic boundary: Environmental impact and modeling of the global carbon cycle , 2005 .

[12]  A. Malthe-Sørenssen,et al.  Release of methane from a volcanic basin as a mechanism for initial Eocene global warming , 2004, Nature.

[13]  L. François,et al.  Basalt weathering laws and the impact of basalt weathering on the global carbon cycle , 2003 .

[14]  P. Olsen,et al.  The great rift valleys of Pangea in eastern North America , 2003 .

[15]  S. Dworkin,et al.  Paleosol barometer indicates extreme fluctuations in atmospheric CO2 across the Cretaceous-Tertiary boundary , 2002 .

[16]  D. Beerling,et al.  An atmospheric pCO2 reconstruction across the Cretaceous-Tertiary boundary from leaf megafossils , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[17]  A. Montanari,et al.  Ascent of Dinosaurs Linked to an Iridium Anomaly at the Triassic-Jurassic Boundary , 2002, Science.

[18]  D. Beerling,et al.  Fossil Plants as Indicators of the Phanerozoic Global Carbon Cycle , 2002 .

[19]  D. Beerling.  Palaeoclimatology (Communication arising): CO2 and the end-Triassic mass extinction , 2002, Nature.

[20]  G. Retallack.  Palaeoclimatology (Communication arising): Triassic–Jurassic atmospheric CO2 spike , 2002, Nature.

[21]  Celine Dessert,et al.  Erosion of Deccan Traps determined by river geochemistry: impact on the global climate and the , 2001 .

[22]  L. Tanner,et al.  Stability of atmospheric CO2 levels across the Triassic/Jurassic boundary , 2001, Nature.

[23]  G. Retallack.  A 300-million-year record of atmospheric carbon dioxide from fossil plant cuticles , 2001, Nature.

[24]  P. Wignall.  Large igneous provinces and mass extinctions , 2001 .

[25]  Ronald Amundson,et al.  Can C3 plants faithfully record the carbon isotopic composition of atmospheric carbon dioxide? , 2000, Paleobiology.

[26]  D. Beerling,et al.  Fossil Plants and Global Warming at the Triassic-Jurassic Boundary. , 1999, Science.

[27]  D. Kent,et al.  Astronomically tuned geomagnetic polarity timescale for the Late Triassic , 1999 .

[28]  Â. Min,et al.  Extensive 200-million-year-Old continental flood basalts of the central atlantic magmatic province , 1999, Science.

[29]  P. Tapponnier,et al.  On causal links between flood basalts and continental breakup , 1999 .

[30]  P. Kelemen,et al.  Large igneous province on the US Atlantic margin and implications for magmatism during continental breakup , 1993, Nature.

[31]  O. Eldholm,et al.  Scratching the surface: estimating dimensions of large igneous provinces , 1993 .

[32]  T. Cerling.  Use of carbon isotopes in paleosols as an indicator of the P(CO2) of the paleoatmosphere , 1992 .

[33]  K. Caldeira,et al.  Carbon dioxide emissions from Deccan volcanism and a K/T boundary greenhouse effect. , 1990, Geophysical research letters.

[34]  J. Quade,et al.  Systematic variations in the carbon and oxygen isotopic composition of pedogenic carbonate along elevation transects in the southern Great Basin, United States , 1989 .

[35]  J. F. Hubert,et al.  Isotopic Imprint of Climate and Hydrogeochemistry on Terrestrial Strata of the Triassic-Jurassic Hartford and Fundy Rift Basins , 1988 .

[36]  S. Self,et al.  Climatic effects of Volcanic eruptions , 1985, Nature.

[37]  Paul B. Hays,et al.  A negative feedback mechanism for the long‐term stabilization of Earth's surface temperature , 1981 .

[38]  Carl Sagan,et al.  Volcanic explosions and climatic change: A theoretical assessment , 1976 .

[39]  P. Renne,et al.  On the ages of flood basalt events , 2003 .

[40]  D. Kent,et al.  Paleomagnetism and cycle stratigraphy of the Triassic Fleming Fjord and Gipsdalen Formations of East Greenland , 1996 .

[41]  R. Schlische,et al.  High-resolution stratigraphy of the Newark rift basin (early Mesozoic, eastern North America) , 1996 .

[42]  R. Berner,et al.  GEOCARB III : A REVISED MODEL OF ATMOSPHERIC CO 2 OVER PHANEROZOIC TIME , 2001 .