Abstract: Late Mississippian Mixed Carbonate-Clastic Sedimentation in Southwestern New Mexico
SIVILS, DAVID J., Texaco Exploration and Production Inc., P.O. Box 3109, Midland TX 79702; D.B. JOHNHSON, Department of Earth and Environmental Sciences, New Mexico Tech, Socorro, NM 87801
Sedimentation during the latest Mississippian is recorded in the Paradise Formation. The Paradise reaches a maximum thickness of 130 m the Big Hatchet Mountain. The stratigraphic interval can be divided into three members; each composed of eight distinctive lithofacies arranged in meter-scale carbonate-clastic cycles. Cycles begin with deeper water shale and or lime mudstones and culminate in grain-rich or oolitic grainstones, reflecting shoaling. Many of the cycles are capped with sandstones or siltstones. The thickness and vertical development of lithofacies was controlled by changes in relative sea level. Relative sea level was governed by a combination of glacioeustasy and regional tectonism. These meter-scale cycles average 500 k.y. in duration making them equivalent to 4th and/or 5th order sequences. Collectively these smaller cycles are grouped into larger cycles that average 5 m.y. in duration. These larger cycles are equivalent to 3rd order sequences, and are similar to coeval cycles in Britain. This similarity to other coeval cycles strongly suggests that sedimentation during the Late Mississippian was controlled by glacioeustasy. Although there is significant organic matter in the Paradise, and facies appropriate for hydrocarbon migration and trapping, high heat flow in the region coupled with extensive diagenesis of both the carbonate detrital clastic facies makes the Paradise an intresting, yet high-risk exploration target.
AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah