Basement Rocks and Structural Evolution of Southern Oklahoma

摘要: Basement rocks in the 17,000 square-mile r egion of southern Oklahoma crop out Wichita and Arbuckle Mountains have been studied subsurface samples f rom 175 wells. The are divided into two contrasting provinces, each completely different from other age petrologic character. Each province has played a role guiding stratigraphic structural evolution overlying Paleozoic strata. older or Eastern p rovince c onsists d ominantly Precambrian massive granites isotopically ated 1,050 to 1, 350 million years. They part an extensive continental craton, upon which sediments thin only slightly disturbed, chiefly by gentle folding block faulting. younger Province sediments, flows, intrusive igneous probable Early Middle Cambrian age. flows consist graywacke, bedded chert, spilitic basalt, rhyolite. As shown drilling supporting seismic data, t hese framework accumulated thickness about 20,000 feet within elongate downwarp craton. extends northwestward long belt 100 miles wide 300 long. It is confined mainly southwestern northern Texas, but probably continues east-