Detrital zircon geochronology and provenance of the Middle to Late Jurassic Paradox Basin and Central Colorado trough: Paleogeographic implications for southwestern Laurentia

Abstract Middle to Upper Jurassic strata in the Paradox Basin and Central Colorado trough (CCT; southwestern United States) record a pronounced change sediment dispersal from dominantly aeolian deposition with an Appalachian source (Entrada Sandstone) fluvial Mogollon and/or Sevier orogenic highlands (Salt Wash Member of Morrison Formation). An enigmatic abundance Cambrian (ca. 527–519 Ma) grains at this provenance transition CCT Escalante Canyon, Colorado, was recently suggested reflect local Ancestral Front Range, despite previous interpretations that basement uplifts were largely buried by Late time. This study aims delineate spatial temporal patterns these sandstones containing within using sandstone petrography, detrital zircon U-Pb geochronology, trace elemental rare-earth (REE) geochemistry. We report 7887 new analyses 31 samples collected seven transects western eastern Utah. Three clusters ages are consistently present (1.53–1.3 Ga, 1.3–0.9 500–300 interpreted sources associated orogen southeastern Laurentia (mid-continent, Grenville, Appalachian, peri-Gondwanan terranes). Ca. 540–500 Ma anomalously abundant locally uppermost Entrada Sandstone Wanakah Formation but either lacking or small fractions overlying Salt Tidwell Members Formation. A comparison REE geochemistry between igneous potential shows primarily magmatic. Although variability both concentrations precludes definitive identification provenance, several considerations suggest distal granitic rhyolitic provinces Southern Oklahoma aulacogen is also likely, addition proximal identified McClure Mountain syenite Wet Mountains, Colorado. The central CCT, particularly Formation, suggests northwesterly transport sourced Rocky Mountains southern Amarillo-Wichita Oklahoma. lack Uncompahgre uplift (southwestern Colorado) acted as barrier CCT.