Interpretation of a Crustal Section across Oklahoma

A new interpretation for a complex crystal section across Oklahoma is derived from the unified study of a wide variety of observations. The set of data includes refraction observations from a reversed profile, reflection data, gravity measurements, well log information and knowledge of the near-surface geology. The model is divided into three parts according to the elevation of the basement surface and the properties of the overlying sediments. The upper portion of the crust is characterized by a major low velocity zone that has participated in vertical movements at major faults crossing the profile. Four continuous interfaces underlie this low velocity zone, the deepest being the crust-mantle boundary at a depth of 46 km. The continuity of these surfaces and the vertical displacements above the low velocity region imply that in this area major tectonic movements are restricted to the portion of the crust which lies above the base of the velocity reversal. Crustal mobility in this area may possibly be related to the presence of this low velocity zone.