STYLE AND TIMING OF DEFORMATION IN THE NORTHERN TEMBLOR RANGE, SOUTHWESTERN SAN JOAQUIN VALLEY, CALIFORNIA

New mapping within the northern Temblor Range, California, shows that transpressional deformation since 3.5-4 Ma may be only the latest in a series of episodes that have produced the southwestern San Joaquin Valley compressional belt. This mapping has revealed the presence of mid-Miocene normal faults that are subparallel to the trend of both the range and the San Andreas Fault, suggesting an extensional regime at ~10-15 Ma. Balanced cross-section construction, constrained by new mapping and well log data, combined with helium dating, will yield a clearer picture of the kinematics of deformation in the Temblor and adjacent ranges. Structural detail not evident in currently published maps can be used to constrain the style of the most recent deformation event and provide information about the number and style of older events in the ranges adjacent to the San Andreas Fault, in particular, it may support the occurrence of an Eocene-Oligocene deformation event in the northern part of the Temblor Range. Once the kinematic evolution of these ranges is constrained, it will be used to test various dynamic models of transpressional deformation.