Homogeneous evolution of this basin did not occur due to dynamic tectonic activity. Despite the active setting, there are over 9,100 m of strata within the basin. The dynamic setting was also responsible for the heterogeneous deposition of each formation. It is common for rock units of the same depositional event to have different names in different locations within the basin. This may be a result of large variation in clast size as with the upper Pliocene Pico Formation in the northwestern part of the basin and the Upper Fernando Formation in the southwest part of the basin.