An understanding of the structural styles associated with sedimentary basin inversion is imperative for predicting hydrocarbon formation, migration, and accumulation. One structural aspect of basin development and inversion that is commonly overlooked is the component of vertical-axis rotation during extension or contraction. Vertical-axis rotation has been documented in every type of tectonic environment and in a wide variety of locations around the world, however this mode of deformation is often unaccounted for in tectonic reconstructions and basin modeling.

The purpose of this study is to evaluate the influence of vertical-axis rotation on the structural style of an actively deforming basin in southern California to develop a model of basin inversion in a rotational environment. Most of the oil-producing basins in southern California have developed in conjunction with Miocene and younger vertical-axis rotation, and the Santa Maria basin in particular offers an excellent natural laboratory in which to study this process.

The new data will help test and refine general dynamic models of tectonic rotation as well as regional tectonic reconstructions of the Pacific-North American plate boundary. The model developed here may also aid in evaluating petroleum reserves in other locations, and will demonstrate the advantages of understanding the influence of rotation on basin development and inversion.