Field excursion: Petroleum traps and structures along the San Andreas convergent strike-slip plate boundary, California

Fault-related fold models that illustrate the geometry and kinematic development of petroleum traps and structures are frequently used to assist basin exploration and development of structurally complex oil fields.Worldwide, several petroleum-rich provinces are situated in convergent strike-slip settings with adjacent convergent structures that are commonly petroleum traps. Strain studies andmodeling of these settings are dominated by the wrench fault model, and examples from the San Andreas fault plate boundary and its trapping influence on adjacent large oil fields in California abound (Wilcox et al., 1973). Use of this model in petroleum exploration and geologic education is problematic and can lead to poor choices and wasted drilling dollars. Here, we show at three field trip stops that the wrench model and its associated flower structures (Harding, 1976) and palm tree structures (Sylvester and Smith, 1976; Sylvester, 1988) fail to explain the oil trapping style and structure of the uppermost crust near the San Andreas fault (Figure 1). Copyright © 2017The American Association of Petroleum Geologists. All rights reserved.