. ▁The ▁fault s ▁pre domin ant ▁tr end ▁is ▁north west - to - s out heast , ▁other ▁n ortheast - to - s outh west ▁tr ends ▁may ▁form ▁part ▁of ▁a ▁conjug ate ▁pattern ▁controlled ▁by ▁the ▁gross ▁texture ▁bas ement . ▁ ▁In ▁Pre - C ret ace ous ▁times , ▁areas ▁that ▁became ▁Sar ir ▁accum ulations ▁were ▁occupied ▁by ▁top ographic ▁high s . ▁It ▁is ▁probable ▁that , ▁even ▁at ▁this ▁time , ▁they ▁were ▁controlled ▁by ▁sets ▁of ▁conjug ate ▁fault s ▁tr ending ▁north west - to - s out heast ▁and ▁n ortheast - to - s outh west . ▁The ▁southern ▁C ▁structure ▁may ▁have ▁been ▁connected ▁to ▁a ▁larger ▁hinter land ▁where ▁C ret ace ous ▁sed iments ▁were ▁derived ▁and ▁subsequently ▁subs ided . ▁ ▁Major ▁fault ▁movement ▁occurred ▁during ▁C ret ace ous ▁sand ▁de position , ▁most ▁evident ▁on ▁north ▁and ▁west ▁fl anks ▁of ▁the ▁C ▁structure ▁subject ▁to ▁u pl ift ▁and ▁er os ion . ▁This ▁is ▁expressed ▁by ▁a ▁dis con form ity ▁that ▁removed ▁success ively ▁deeper ▁res er voir ▁b eds ▁to ▁the ▁north ▁and ▁west . ▁Major ▁down war ping ▁to ▁the ▁south ▁probably ▁began ▁near ▁the ▁end ▁of ▁the ▁C ret ace ous ▁period , ▁isol ating ▁the ▁C ▁structure ▁from ▁its ▁hinter land , ▁forming ▁it ▁into ▁a ▁trap , ▁and ▁providing ▁a ▁deep ▁sh ale ▁tr ough ▁that ▁may ▁have ▁been ▁a ▁major ▁hydro car bon ▁generating