Print this pageHistorically, modern tropical-water carbonates have been the analogue for ancient carbonate platforms. Modern temperate-water carbonates increasingly are being studied and recognized as analogues for many ancient carbonate ramps and reservoirs. We do not have good 3-D models for Cenozoic temperate-water carbonate ramps, especially those with variable substrate paleoslopes. This study evaluates controls on such ramps from an example in the Miocene, formulating a model useful in predicting facies distribution in petroleum reservoirs.
This study evaluates the relative importance that sediment bypass, paleotopographic morphology, siliciclastic influx, windward vs. leeward position, autocyclic processes, and relative sea-level changes have in controlling facies distribution and architecture in ramps with variable substrate paleoslopes. The study is of temperate-water carbonate ramp strata in the Upper Miocene (Tortonian) in the Cabo de Gata region of SE Spain. Here, strata overlie Neogene volcanic basement topography that formed an archipelago. This area is excellent for evaluating the controls on facies distribution and ramp architecture because of the complex topography of the archipelago setting, excellent three dimensional outcrop, and preserved paleotopography.
Facies mapping, measurement of many stratigraphic sections, 2-D cross-sections on photomosaics, and lateral correlation of surfaces are used to construct 3-D cross-sections of facies distribution. These 3-D cross-sections yield a 3-D model isolating the controls listed above and documenting facies distribution.
AAPG Search and Discovery Article #90925©1999 AAPG Foundation Grants-in-Aid