Velocity modeling with complex tectonics; example from the San Joaquin forearc basin, California

Abstract

Lateral velocity variations across steep thrust faults or steeply dipping beds are difficult to incorporate in velocity models where structure is usually controlled by unfaulted, single-z grids. The west side of the San Joaquin basin is a tectonically complex environment with steep dips, unconformities, variable fault geometries, complex basement lithologies, and outcrops to the west. All of these contribute to a complex structural model that is important to capture in velocity modeling to allow for the most accurate depth conversion. In the past, geologic models had to be manually manipulated to account for discrete fault blocks. This process is time-consuming and difficult to update as interpretations change. Here we show how we are able to build a dynamic framework and resulting velocity model that accounts for fault offset, unconformities, and geologic history.

AAPG Datapages/Search and Discovery Article #90266 © 2016 AAPG Pacific Section and Rocky Mountain Section Joint Meeting, Las Vegas, Nevada, October 2-5, 2016