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| Watkins, J S; Moore, J C; Shipley, Th; Bachman, S B; Beghtel, F W; Butt, A; Didyk, B M; Leggett, Jk; Lundberg, N; Mcmillen, Kj; Niitsuma, N; Shepherd, Le; Stephan, Jf; Stradner, H. |
| During Leg 66 eight sites were drilled to form a transect across the Middle America Trench off southwestern Mexico. Cores from these sites show that accretion began approximately 10 MY ago and has continued to the present. Accretion began with offscraping followed by a 2- to 4- MY episode of folding and faulting with uplift rates of 400-500 m/MY; uplift then slowed to 100-200 m/MY, and seismically resolved deformation ceased as the wedge appeared to rise evenly. Approximately 33% of the sediment flux input into the subduction zone, mainly trench sand and slump deposits, is scraped off and incorporated into the toe of the lower slope; an additional 33% is initially subducted but then peeled off to underplate the accretionary wedge; the remaining 33% is... |
| Tipo: Text |
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| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/00245/35668/34176.pdf |
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| Buffler, R T; Shaub, F J; Huerta, R; Ibrahim, Abk; Watkins, J S. |
| Seismic data from the deep Gulf of Mexico basin indicate: 1) inferred ocenaic crust in the deep central Gulf (5 to 6 km thick; 6.8 to 7.1 km/sec.) is flanked symmetrically on the north and south by inferred transitional crust (8 to 15 km thick; 6.4 to 6.8 km/sec.); 2) acoustic basement seen on the reflection data in the central Gulf is an irregular reflector and probably represents the top of an oceanic volcanic (basaltic) layer (layer 2); 3) northof the Campeche Escar pment the top of transitional crust is represented by a strong, smooth reflector/unconformity that truncates rift basins and is onlapped by a thick salt and sedimentary section; 4) in the southeastern Gulf transitional crust consists of tilted basement blocks probably representing a thinned... |
| Tipo: Text |
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| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/00246/35679/34187.pdf |
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