HR: 1340h
AN: V13A-0519    [Abstracts]
TI: Duration and Eruptive Chronology of CAMP: Implications for Central Atlantic Rifting and the Triassic-Jurassic Boundary
AU: * Nomade, S
EM: sebastien.nomade@cea.fr
AF: Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94709 United States
AU: * Nomade, S
EM: sebastien.nomade@cea.fr
AF: Department of Earth and Planetary Science, University of California, Berkeley, CA 94720 United States
AU: * Nomade, S
EM: sebastien.nomade@cea.fr
AF: CEA-LSCE, UMR 1572, ORME LES MERISIERS, Gif Sur Yvette, 91191 France
AU: Knight, K B
EM: kbk@berkeley.edu
AF: Department of Earth and Planetary Science, University of California, Berkeley, CA 94720 United States
AU: Beutel, E
EM: beutele@cofc.edu
AF: Department of Geology, College of Charleston, Charleston, Charleston, SC 29412 United States
AU: Renne, P R
EM: prenne@bgc.org
AF: Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94709 United States
AU: Renne, P R
EM: prenne@bgc.org
AF: Department of Earth and Planetary Science, University of California, Berkeley, CA 94720 United States
AU: Verati, C
EM: verati@unice.fr
AF: Université de Nice Sophia-Antipolis, UMR Géosciences Azur, Parc Valrose, Nice, 06108 France
AU: Feraud, G
EM: feraud@unice.fr
AF: Université de Nice Sophia-Antipolis, UMR Géosciences Azur, Parc Valrose, Nice, 06108 France
AU: Marzoli, A
EM: andrea.marzoli@unipd.it
AF: Dipartimento di Mineralogia e Petrologia, Universita' di Padova, c. Garibaldi 37, Padova, 35137 Italy
AB: The Central Atlantic Magmatic Province (CAMP) is among the largest igneous provinces on Earth, emplaced synchronously with or just prior to the Triassic-Jurassic boundary ca. 200 Ma. In great part due to the controversial connection between the occurrence of CAMP and the events of the Triassic-Jurassic boundary, the demand for better constraints on the duration and eruptive chronology of this province has increased. A careful review and selection of available ages, as well as 16 new ages from the Carolinas, Newark basin (US), French Guyana and Morocco are presented. Judicious selection yields a total of 59 dates for CAMP, ranging from 202 to 190 Ma covering every part of the CAMP. Extrusive activity commenced abruptly around 200 Ma, reaching peak volume and intensity around 199 Ma on the African margin. The main period of CAMP magmatism is confirmed as brief, but is suggested to consist of at least two phases over 1.5 Ma, during which time data suggest a southward migration of the magmatism from the Africa-North American margins towards South America. Two volumetrically minor, but distinctive magmatic peaks at 195 and 192 Ma are mirrored in data from all three continents, highlighted by our statistical approach. Despite significant advances in our understanding of the chronology of CAMP, we emphasize that the lack of a well-defined Triassic-Jurassic boundary age, as well as an absence of relevant comparison between U/Pb and Ar/Ar data for this time period remain limiting factors to unambiguously linking CAMP in time with the events of the Triassic-Jurassic boundary.
DE: 1037 Magma genesis and partial melting (3619)
DE: 1100 GEOCHRONOLOGY
DE: 1135 Correlative geochronology
DE: 8105 Continental margins: divergent (1212, 8124)
DE: 8137 Hotspots, large igneous provinces, and flood basalt volcanism
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005