Abstract

Sedimentary units of the Cherry Canyon Formation were deposited during Permian (Guadalupian) time in the Delaware Basin, shallow, semi-restricted, epicontinental sea. This formation is composed of fine-grained sandstones, siltstones, basinal carbonates, and organic-rich, fine-grained siltstones deposited in submarine fan systems. This study was undertaken to reevaluate the likeliest mechanism by which the siliciclastics bypassed the shelf carbonates and were deposited in the basin, to define depositional building blocks for subsurface interpretations of submarine fan architecture in this basin, and to produce a model for application to similar deposits. The DB-03 well, drilled by Gulf Research and Development Company in 1985, was the primary data base for this work.

In this study, three orders of depositional building blocks could be recognized and their stacking patterns documented. Subcycles are small-scale coarsening-upward packages likely produced by short-term depositional processes. Cycles are intermediate order building blocks, bound by periods of sediment starvation. “Supercycles” are coarsening- then fining-upward packages of several cycles representing longer term relative sea-level variation.

Approximately 30 cycles were developed during the nearly three million year time frame of Cherry Canyon deposition. Based on lithologic stacking patterns, cycles are best interpreted as representing relative sea-level change with a ∼100,000 year cyclicity (fourth-order). Time series analysis supports this interpretation of cycle duration. Potential reservoir sandstones are isolated within “cycles” and vary in lateral extent.

In total, the lithologies within the Cherry Canyon Formation represent ∼30 4th-order (0.08-0.5 Ma duration) changes in relative sea-level (Cycles -3 through 27), superimposed on three 3rd-order (.5-3 Ma duration) sea-level cycles (Supercycles 1, 2, and 3). These three 3rd-order cycles are, in turn, a part of a 2nd-order (3-50 Ma duration) cycle of relative sea-level change.