Systematic and Episodic Structural Deformation in Southern Kansas and Implications for Petroleum Systems and CO2 Storage
Lynn Watney, John Youle, Dennis Hedke, Paul Gerlach, Ray Sorenson, Martin Dubois, Larry Nicholson, David Koger, Ralph Baker, and Debra Higley
A regional geologic investigation of southern Kansas is being completed as part of the evaluation of CO2 storage potential. The area investigated encompasses the Anadarko Basin and its extension, the Hugoton Embayment, and the Sedgwick Basin on the east. The much deeper Anadarko Basin is defined on its south by the prominent NW-trending Amarillo-Wichita frontal fault zone (AW), a reactivated element of the Early Cambrian southern Oklahoma aulacogen associated with up to 10 km of total structural relief. The Nemaha Uplift (NU) forms the eastern border of the Sedgwick Basin a product of structural reactivation of the Proterozoic Midcontinent rift system (MRS). Both features exhibit wrench faulting, most notably along the AW. Regional fault zones in southern Kansas include sets of mostly NW and NE-trending high angle reverse faults with vertical offsets in excess of 200 m confirmed by regional 3D seismic. Some faulting is clearly tied to the MRS as far west as Seward County in SW Kansas. Major tectonic activity of all these fault systems occurred during the Ouachita Orogeny in late Mississippian through middle Pennsylvanian time and the orogeny initiated a major pulse of thermal maturation of petroleum and its migration. From the middle Pennsylvanian through Permian subsequent or continuing tectonic movement reactivated NW and NE oriented rhombus shaped structural blocks (1–10s km) with subtle variations in relief (generally meter to ~ 70 m) and slope (near zero to upwards of 2–3 m/km). Deformation bands circumscribe these basement blocks, and many of them can be detected at the surface through photo geologic and satellite mapping techniques and correlating to basement heterogeneity. The deformation bands influenced petroleum migration pathways into southern Kansas while differential relief on basement blocks strongly affected sedimentation and resulted in unique facies distribution patterns between adjacent blocks.
AAPG Search and Discovery Article #90176©AAPG Mid-Continent Meeting, Wichita, Kansas, October 12-15, 2013