André W. Droxler2,
(1) Cia. Perez Companc, Caracas, Venezuela
(2) Rice University, Houston, TX
(3) Morrice and Associates, Denver, CO
Abstract: The origin and Cenozoic evolution of the Belize Barrier Reef and offshore atolls
Our study is based upon Shell and Pecten multi channel and Rice high resolution single channel seismic lines, and well log information from nine industrial offshore wells. The thrusted block of Camels Hump formed during the Paleocene translation of the Caribbean plate along the Yucatan eastern margin. Its load generated Camels Basin, whereas Gladden and Turneffe Basins formed as pull-aparts. Carbonate platforms were established in the late Eocene/Oligocene on top of isolated tectonic highs referred to as Camels Hump, Turneffe, Glovers, and Lighthouse. The carbonate platforms on the southern portions of Camels Hump and Glovers were partially drowned in the early/middle Miocene. During the middle/late Miocene, tectonic enhancement of Camels Hump and Glovers highs triggered the partial collapse of their margins and is recorded by mass wasting deposits in Gladden Basin. In the early Pliocene, the Maya Mountains shed more sediments into Camels Basin, whereas the northern part of Camels Hump remained a carbonate platform. The late Pliocene/early Pleistocene systematic sea level lowering moved the shoreline eastward where siliciclastic sediments were redistributed by longshore currents along the eastern flank of Camels Hump and in the northern Camels Basin. The well-developed portions of the modern Belize Barrier Reef itself are interpreted to represent the upper part of a thin coralgal carbonate unit, initially deposited in the middle of the Brunhes Epoch (about 0.45 Ma) over those late Pliocene/early Pleistocene lowstand siliciclastic beach ridges and coastal deposits established along the eastern flank of Camels Hump and in the northern Camels Basin.
AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana