1. Oceanic Core Complex and crustal accretion a slow-spreading ridges
- Author
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Ildefonse, B., Blackman, D., John, B. E., Ohara, Y., Miller, D. J., Macleod, C. J., Abe, N., Abratis, M., Andal, E. S., Andréani, M., Awaji, S., Beard, J. S., Brunelli, Daniele, Charney, A. B., Christie, D. M., Delacour, A. G., Delius, H., Drouin, M., Einaudi, F., Escartin, J., Frost, B. R., Fryer, P. B., Gee, J. S., Godard, M., Grimes, C. B., Halfpenny, A., Hansen, H. E., Harris, A. C., Hasebe, A. T., Hayman, N. W., Hellebrand, E., Hirose, T., Hirth, J. G., Ishimaru, S., Johnson, K. T. M., Karner, G. D., Linek, M., Maeda, J., Mason, O. U., Mccaig, A. M., Michibayashi, K., Morris, A., Nakagawa, T., Nozaka, T., Rosner, M., Searle, R. C., Suhr, G., Tominaga, M., VON DER HANDT, A., Yamasaki, T., Zhao, X., Géosciences Montpellier, Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Sciences de la Terre (LST), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre, de l'Environnement et de l'Espace de Montpellier (ISTEEM), Centre National de la Recherche Scientifique (CNRS)-Université Montpellier 2 - Sciences et Techniques (UM2), Atmosphere and Ocean Research Institute [Kashiwa-shi] (AORI), The University of Tokyo (UTokyo), School of Earth and Ocean Sciences [Cardiff], and Cardiff University
- Subjects
010504 meteorology & atmospheric sciences ,Pluton ,Geochemistry ,core complex ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,010502 geochemistry & geophysics ,01 natural sciences ,Atlantis fracture zone ,14. Life underwater ,ocean drilling ,ComputingMilieux_MISCELLANEOUS ,[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography ,0105 earth and related environmental sciences ,Peridotite ,[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics ,geography ,geography.geographical_feature_category ,Gabbro ,lower oceanic crust ,Geology ,Mid-ocean ridge ,Mid Atlantic Ridge ,Seafloor spreading ,Detachment fault ,Oceanic core complex ,Mafic ,gabbro - Abstract
IODP Expedition 304/305 Science Party 2007; International audience; Oceanic core complexes expose gabbroic rocks on the seafloor via detachment faulting, often associated with serpentinized peridotite. The thickness of these serpentinite units is unknown. Assuming that the steep slopes that typically surround these core complexes provide a cross section through the structure, it has been inferred that serpentinites compose much of the section to depths of at least several hundred meters. However, deep drilling at oceanic core complexes has recovered gabbroic sequences with virtually no serpentinized peridotite. We propose a revised model for oceanic core complex development based on consideration of the rheological differences between gabbro and serpentinized peridotite: emplacement of a large intrusive gabbro body into a predominantly peridotite host is followed by localization of strain around the margins of the pluton, eventually resulting in an uplifted gabbroic core surrounded by deformed serpentinite. Oceanic core complexes may therefore reflect processes associated with relatively enhanced periods of mafic intrusion within overall magma-poor regions of slow- and ultra-slow-spreading ridges.
- Published
- 2007
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