| The Long Beach oil field, an en echelon faulted anticline, formed as a result of simple wrench faulting along the Newport-Inglewood Fault Zone between late Pliocene and Pleistocene time. The structural and stratigraphic history of this field is important in understanding the development of southern California and for renewed exploitation of the field.;Recent trench exposures and subsurface interpretations reveal the field is cut by two faults that penetrate upper Miocene through Pleistocene strata: the Cherry Hill fault to the southwest and the Signal Hill fault to the northeast. The Signal Hill fault is considered a splay off of the Cherry Hill fault. Measured horizontal and vertical separation for the Cherry Hill fault is 1,150' and 425', respectively. For the Signal Hill fault horizontal and vertical separation is 150' and 30'. Separation values and rates suggest the faults were active as recently as late Pliocene or early Pleistocene. |
