Wade D Hutchings¹

(1) Marathon Oil Company, Houston, TX

ABSTRACT: Sequence Stratigraphy of the Permian Delaware Mountain Group, Basin Floor Setting, Delaware Basin, West Texas and Southeastern New Mexico: Application of Stacking Pattern Analysis

The Permian Delaware Mountain Group (DMG) consists of cyclic packages of sandstone, siltstone, carbonate mudstone, and organic-rich siltstone that were deposited in the Delaware Basin during Guadalupian time. Three orders of stratigraphic cyclicity are recognized in the DMG: eight low-order cycles, 32 intermediate-order cycles, and more than 50 high-order cycles. Low and intermediate-order cycles are similar in scale to composite and high-frequency sequences. All cycles are bounded by organic-rich siltstones or carbonate mudstones that represent periods of sediment starvation in the basin.

Stacking pattern analysis combined with other stratigraphic tools can be effectively used in the unlimited-accommodation setting of the DMG. High-frequency cyclicity is better expressed in the distal, basin-floor setting of the Delaware Basin due to more complete stratal preservation than in proximal, slope settings. A one-dimensional stratigraphic framework from the basin center correlates over long distances in the northern Delaware Basin.

Regional correlation of low-order cycles characterized by upward-thinning cycle stacking patterns identifies a dynamic depositional system that is linked closely to stratigraphic position within low and intermediate-order cycles. In most low-order cycles, basal intermediate-order cycles thicken basinward and upper cycles thicken slopeward in response to changing accommodation conditions on the coeval carbonate shelf.

Correlation of several limestone intervals to the PDB-04 core and the Guadalupe Mountains aid in allowing a comparison between low-order cycles from the basin and composite sequences from the shelf. This comparison supports reciprocal sedimentation concepts at several orders, and combined with basin-restricted cross-sections documents a high degree of stratigraphic organization for the DMG.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado