Dolomitization of laminated and burrowed sediments produced porosity in the C interval. Syndepositional precipitation of dolomite may have also occurred in this interval. The C zone has moderate variation in thickness, generally fair to good porosity, but poor permeability. It is inferred that early dolomitization, with its concomitant loss of permeability produced by extensive intergrowth of dolomite rhombohedrons, prohibited the C zone interval from being an effective petroleum reservoir. Because of low permeability, these dolomites appear to have been poorly affected by hydrothermal fluids and late diagenetic dolomite replacement or recrystallization like the underlying D zone.
Fractures are absent to sparse and appear to have no control on permeability.