PICCOLI, LEONARDO H., University of Wisconsin, Dept. of Geology and Geophysics, Madison, WI

ABSTRACT: Integrated Sedimentologic-Seismic Study of Icehouse Carbonate Platforms: An Example from the Wolfcampian (Permian) in West Texas

The proposed study combines outcrop, synthetic seismic, seismic attributes, and outcrop seismic imaging; and it will provide a unique template for Late Paleozoic carbonate platforms, specially those deposited during ice-house climatic periods.

This project will contribute with a significant insight in the 3D facies distribution and evaluation of sequence and seismic stratigraphic concepts in carbonate systems. It will concentrate on Wolfcampian carbonates in the Hueco Mountains of West Texas, near El Paso. These outcrops are important analogs to Paleozoic hydrocarbon producing intervals of the same age in Texas and New Mexico.

The Hueco Mountains are characterized by shelf, slope and basinal carbonates systems developed during this icehouse period. The Hueco Group shelf strata consist of fine grained, grain supported cyclic carbonates that grade into shelf margin facies, mainly composed of algal bioherms and fusulinid-rich shoals. Bioherm-derived breccias and fusulinid wackestones dominate slope facies. The basinal section is composed of cherty mudwackestones and turbidites. Lateral and vertical facies changes occur in short distances, particularly near the shelf margin. The Hueco Group can be subdivided into highfrequency sequences (HFS); conspicuous sequence boundaries on the shelf (amalgamated sequence boundaries) expand basinward probably reflecting different hierarchical orders of sea-level falls. The result of this heterogeneity is a series of stacked platforms, each with distinctive facies and geometries.

The results of this study are relevant to icehouse platforms, which are strongly controlled by high-amplitude, high frequency sea-level changes that affect the distribution of facies due to unfilled accommodation space and preserved topography.

AAPG Search and Discovery Article #90909©2000 AAPG Foundation Grants-in-Aid