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Detailed Reference Information |
Jackson, M.P.A., Hudec, M.R. and Hegarty, K.A. (2005). The great West African Tertiary coastal uplift: Fact or fiction? A perspective from the Angolan divergent margin. Tectonics 24: doi: 10.1029/2005TC001836. issn: 0278-7407. |
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We explore exhumation in the coastal Kwanza Basin by combining analyses of Tertiary hiatuses and apatite fission tracks. Planktonic biozones show five major hiatuses in the Oligo-Miocene and Plio-Pleistocene. Between gaps, Oligo-Miocene strata accumulated under marine conditions. A marine setting refutes the idea of a massively raised coastal plateau in the mid-Tertiary. Marine conditions continued until ~5 Ma. Fission track data suggest three thermal events: ~150 Ma, during rifting and volcanism; ~100--70 Ma, during shortening and volcanism; and ~20--10 Ma, during exhumation. Tertiary uplift was spatially highly variable. For the Kwanza Basin, we infer that Tertiary uplift on the West African margin is indeed a fact but that estimates of uplift timing and size are unreliable when extrapolated to adjoining areas. Massive uplift (2000--4000 m) of the Precambrian craton had little structural effect in the outer basin. Instead, minor uplifts on the shelf drove late Tertiary deformation on the slope. |
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Abstract |
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Keywords
Structural Geology, Continental neotectonics, Geochronology, Thermochronology, Tectonophysics, Tectonics and landscape evolution, Geographic Location, Africa, divergent margin, coastal uplift, apatite fission track, salt tectonics, Angola, hydrocarbon maturation |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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