Effect of Scale on High-Gradient Carbonate Slope Deposition

Ted E. Playton
Jackson School of Geosciences, The University of Texas at Austin
Austin, Texas
[email protected]

Many of the largest oil fields in the world produce out of enormous ancient carbonate platforms. Undoubtedly, these platforms have associated carbonate slope-to-basin transitions, but are historically under-explored and poorly understood. However, past carbonate slope studies have addressed issues such as 1.) the various types of carbonate slope profiles and gradients, 2.) carbonate slope facies and facies distributions, 3.) the differences between clastic and carbonate slopes, and 4.) the slope response to accommodation changes on the platform top. Slope profile scale (slope height and profile dip length) may act as a significant control on slope facies distribution, slope morphology evolution, and the timing of sediment delivery to the slope. A quantification of this type that addresses the control of scale on carbonate slope deposition constrained within a sequence stratigraphic context has not been done to date, and would significantly aid in the understanding and prediction of carbonate slope accumulations as potential hydrocarbon reservoirs.

This study is to examine the sequence stratigraphic relationships and facies distributions of several ancient, high-gradient carbonate slope exposures of varying scales. Variations in sediment distribution patterns and proportions constrained within a sequence stratigraphic context will be documented from kilometer- to 100-meter-scale slope outcrop examples to demonstrate any effect that slope profile scale may have on internal and external sediment organization, occurrence, and morphology. Generalized depositional models will be constructed to exhibit these effects of scale, and can be used to enhance exploration and production in carbonate slope settings through utilization of better prediction methods.

AAPG Search and Discovery Article #90033©2004 AAPG Foundation Grants-in-Aid