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Gutscher, Marc-andre; Olivet, Jean-louis; Aslanian, Daniel; Eissen, Jp; Maury, Rene. |
Since flat subduction of the Nazca Plate beneath Peru was first recognized in the 1970s and 1980s a satisfactory explanation has eluded researchers. We present evidence that a lost oceanic plateau (Inca Plateau) has subducted beneath northern Peru and propose that the combined buoyancy of Inca Plateau and Nazca Ridge in southern Peru supports a 1500 km long segment of the downgoing slab and shuts off arc volcanism. This conclusion is based on an analysis of the seismicity of the subducting Nazca Plate, the structure and geochemistry of the Marquesas Plateau as well as tectonic reconstructions of the Pacific¿Farallon spreading center 34 to 43 Ma. These restore three sub¿parallel Pacific oceanic plateaus; the Austral, Tuamotu and Marquesas, to two Farallon... |
Tipo: Text |
Palavras-chave: Nazca Plate; Subduction; Nazca Ridge; Peru; Reconstruction. |
Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/1999/publication-360.pdf |
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Lagabrielle, Yves; Asti, Riccardo; Fourcade, Serge; Corre, Benjamin; Poujol, Marc; Uzel, Jessica; Labaume, Pierre; Clerc, Camille; Lafay, Romain; Picazo, Suzanne; Maury, Rene. |
In two companion papers, we report the detailed geological and mineralogical study of two emblematic serpentinized ultramafic bodies of the western North Pyrenean Zone (NPZ), the Urdach massif (this paper) and the Saraille massif (paper 2). The peridotites have been exhumed to lower crustal levels during the Cretaceous rifting period in the future NPZ. They are associated with Mesozoic pre-rift metamorphic sediments and small units of thinned Paleozoic basement that were deformed during the mantle exhumation event. Based on detailed geological cross-sections and microprobe mineralogical analyses, we describe the lithology of the two major extensional fault zones that accommodated: (i) the progressive exhumation of the lherzolites along the Cretaceous basin... |
Tipo: Text |
Palavras-chave: North Pyrenean Zone; Urdach; Mantle exhumation; Fluid-rock interactions; Listvenites; Greenschist facies; Detachment faults; Late Cretaceous. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00637/74920/76106.pdf |
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Daoud, Mohamed A.; Le Gall, Bernard; Maury, Rene; Rolet, Joel; Huchon, Philippe; Guillou, Herve. |
The Tadjoura rift forms the westernmost edge of the westerly propagating Sheba ridge, between Arabia and Somalia, as it enters into the Afar depression. From structural and remote sensing data sets, the Tadjoura rift is interpreted as an asymmetrical south facing half-graben, about 40 km wide, dominated by a large boundary fault zone to the north. It is partially filled up by the 1-3 Myr old Gulf Basalts which onlapped the older Somali Basalts along its shallower southern flexural margin. The major and trace element analysis of 78 young onshore lavas allows us to distinguish and map four distinct basaltic types, namely the Gulf, Somali, Goumarre, and Hayyabley Basalts. These results, together with radiometric age data, lead us to propose a revised... |
Tipo: Text |
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Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00200/31103/29502.pdf |
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Talandier, Jacques; Hyvernaud, Olivier; Maury, Rene. |
We analyze two seismic events that occurred on 27 May 2011 and 29 April 2013 at the Rocard submarine volcano which overlies the Society hot spot. The Polynesian Seismic Network recorded for the first time unusual associated short-and long-period signals, with perfectly monochromatic (0.0589 Hz) Rayleigh wave trains of long period and duration. None of the numerous observations of long-period (10-30 s) signals previously associated with volcanic activity in Japan, Italy, Mexico, Indonesia, Antarctica, and the Hawaiian Islands have the characteristics we observed at Rocard. We propose a tentative model for these unusual and rather enigmatic signals, in which the movement of lava excited the resonance of a shallow open conduit under a high hydrostatic... |
Tipo: Text |
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Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00639/75083/75614.pdf |
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