Kaiparowits and Black Mesa Basins: Stratigraphic Synthesis

ABSTRACT The Kaiparowits and Black Mesa basins are in the Colorado Plateau structural province. Through most of Paleozoic and Mesozoic time, these basins occupied the shelf area between the Ancestral Sierra Grande part of the Transcontinental arch on the east and the Cordilleran geosyncline on the west. Sedimentary rocks representative of all the Paleozoic systems are present except Ordovician and Silurian. Paleozoic strata are periodic products of marine-shelf sedimentation. Stratigraphic controls and depositional strike were determined by low landmasses and embayments into the shelf area. The Mesozoic Era began with a drastic change in sedimentation from dominantly marine carbonates and associated rocks to Triassic redbeds, reflecting a complex, dominantly continental environment of fluvial, eolian, alluvial, lacustrine, paludal, and marine deposits. Large anticlinal features occur in both basins. These appear to have had an early history of growth and offer possibilities for oil and gas production. More difficult to define are the numerous stratigraphic terminations which may prove to be the traps of large petroleum accumulations.