The occurrence and production of petroleum in the Quality Pool is partially controlled by a large-scale, previously unknown, dextral/normal wrench-fault system. This system, herein referred to as the 38 Fault system, possesses striking similarities with the nearby San Andreas Fault, and may in part be responsible for the Spellacy anticlinorium, and a number of important spatially associated, low-angle, normal faults and flower structures defined by recent mapping. At many locations the occurrence and quantity of oil production is either demonstrably controlled by or spatially associated with the 38 Fault system. Evidence is presented for the movement of both fracture- and bedding-controlled fluids locally characterized by petroleum, two stages of gypsum deposition, pyrite/limonite/hematite deposition, silicification and argillization. Fault kinematics, paleo-stress fields and fluid geochemistry are integrated into a comprehensive structural model directed to both production and exploration interests.
AAPG: The Influence of Stress Regimes on Fluid Migration and Entrapment