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Lallemand, S; Collot, J-y; Pelletier, B; Rangin, C; Cadet, J-p. |
This paper presents some of the implications of oceanic asperities in subduction zones, based on examples gathered during the world circumnavigation of R/V Jean Charcot . The study of these examples provides a new overview of active margin modelling in response to asperity subduction. It is concluded that both erosion and accretion may be governed by the oceanic plate even though frontal tectonic erosion is better documented because it is accessible to conventional surveys. Most of the time, erosion is due to the relaxation of the arc slope in the wake of asperity/subduction. |
Tipo: Text |
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Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00268/37957/36038.pdf |
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Sibuet, Jean-claude; Rangin, C; Le Pichon, X; Singh, S; Cattaneo, Antonio; Graindorge, D; Klingelhoefer, Frauke; Lin, Jing-yi; Malod, Jacques-andre; Maury, Tanguy; Schneider, J; Sultan, Nabil; Umber, Marie; Yamaguchi, H. |
Trench-parallel thrust faults verging both landward and seaward were mapped in the portion of wedge located between northern Sumatra and the Indian-Indonesian boundary. The spatial aftershocks distribution of the 26th December 2004 earthquake shows that the post-seismic motion is partitioned along two thrust faults, the Lower and Median Thrust Faults, the latter being right-laterally offset by a N-S lower plate fracture zone located along the 93.6 degrees N meridian. Between February 2005 and August 2005, the upper plate aftershock activity shifted from southeast of this fracture zone to northwest of it, suggesting that the lower plate left-lateral motion along the fracture zone may have induced a shift of the upper plate post-seismic activity along the... |
Tipo: Text |
Palavras-chave: Active thrust faults; Co seismic rupture; Aftershocks; 2004 Sumatra Andaman earthquake. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3508.pdf |
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Graindorge, D; Klingelhoefer, Frauke; Sibuet, Jean-claude; Mcneill, L; Henstock, T; Dean, S; Gutscher, M; Dessa, J; Permana, H; Singh, S; Leau, H; White, N; Carton, H; Malod, Jacques-andre; Rangin, C; Aryawan, K; Chaubey, A; Chauhan, A; Galih, D; Greenroyd, C; Laesanpura, A; Prihantono, J; Royle, G; Shankar, U. |
We present results from multibeam bathymetric data acquired during 2005 and 2006, in the region of maximum slip of the 26 Dec. 2004 earthquake (Mw 9.2). These data provide high-resolution images of seafloor morphology of the entire NW Sumatra forearc from the Sunda trench to the submarine volcanic arc just north of Sumatra. A slope gradient analysis of the combined dataset accurately highlights those portions of the seafloor shaped by active tectonic, depositional and/or erosional processes. The greatest slope gradients are located in the frontal 30 km of the forearc, at the toe of the accretionary wedge. This suggests that long-term deformation rates are highest here and that probably only minor amounts of slip are accommodated by other thrust faults... |
Tipo: Text |
Palavras-chave: Sumatra; Tectonic; Seafloor morphology; Accretionary wedge; Subduction. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-5166.pdf |
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Juteau, T; Eissen, Jp; Francheteau, J; Needham, David; Choukroune, P; Rangin, C; Seguret, M; Ballard, Rd; Fox, Pj; Normark, Wr; Carranza, A; Cordoba, D; Guerrero, J. |
Fort y basaltic rocks collected by submersible during the "Cyamex" expedition (1978) on the East PacifIc Rise at 21 oN, a moderately fast spreading segment (6 cm/year opening rate) of the mid-ocean ridge, consist of angular pillow fragments and glass buds, sheet-flow slabs and samples of columnar pillars standing in collapsed fossillava pools. Most of the rocks are from the crestal are a of the Rise. The collection shows a striking petrographic homogeneity wh en compared with the range of basalts found on other segments of midocean ridges: olivine-phyric, or highly plagioclase-phyric rocks, so common in the slowspreading "Famous" are a in the Atlantic, are absent. All samples are typical lowpotassium oceanic tholeiites with a limited fractionation trend.... |
Tipo: Text |
Palavras-chave: Dorsale Est-PacifIque Pétrologie des basaltes sous-marins Coussins; Laves fluides; Piliers Générations de cristaux Globules de sulfure East Paciflc Rise Petrology of submarine basalts Pillows; Sheet flows; Pillars Generations of crystals Sulphide globules. |
Ano: 1980 |
URL: http://archimer.ifremer.fr/doc/00323/43430/43112.pdf |
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Pautot, G; Rangin, C; Briais, A; Beuzart, P; Lericolais, G; Mathieu, X; Wu, J; Han, S; Li, H. |
We use observations from the 1985 R.V. Charcot Nanhai Cruise to document NW-SE spreading in the 150-200 km wide region of the South China Sea (SCS), along the 1000 km long axial ridge. The data include Seabeam and single channel seismic profiles, completed by magnetic and gravity anomalies. Two detailed surveyed boxes were performed on both sides of the ridge to illustrate the structural fabric. A fine scale structural survey of the flank of a seamount with a side-scan sonar is also presented, as well as dredges and cores results. |
Tipo: Text |
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Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00268/37942/36023.pdf |
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Rangin, C; Francheteau, J. |
Manned submersible observations on a transect from the axis of the East Pacific Rise (21 degree N) to the area of the Brunhes-Matuyama magnetic inversion were made during the Cyamex and Rise diving phases of the Rita project. In the northern part of the study area, axial, linear, 400 to 600 m-wide topographic highs are formed by relatively unfaulted fresh pillow-lava-flows (zone 1). Flanking the axis of recent volcanism is a 1,200 to 1,500 m-wide zone of highly fractured volcanic hilly terrain (zone 2). Zone 3, could represent a former, large flooding episode of the sea floor at the axis of the Rise. Tectonic activity is particularly evident in zone 2, decreases rapidly across strike, and vanishes 12 km from the axis of the East Pacific Rise. The... |
Tipo: Text |
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Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/00246/35691/34199.pdf |
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