A systematic synthesis of regional-scale petroleum systems in the Central Rocky Mountains reveals that Carboniferous (especially Mississippian) source rocks are more important than suggested by the prevailing paradigm. Specific examples within this paradigm shift include the giant reserves of Rangely field (Pennsylvanian-Permian Weber Sandstone) and the super-giant tar accumulations along the San Rafael Swell. These accumulations are historically, but erroneously, assigned to the Permian (Phosphoria) charged petroleum system. Instead, these Carboniferous sourced hydrocarbons can now be clearly differentiated from those correlated to the Permian by specific molecular fingerprints, as well as by differences in the fundamental bulk properties. This conclusion is geologically reinforced with the geographic distribution of effective source rock facies, and the molecular differences are consistent with specific traits of each respective source rock system. Conditions that promoted the formation of Carboniferous source rocks includes deposition in a restricted circulation and sediment-starved setting, whereas the Permian system was promoted by high primary productivity in an upwelling zone. These fundamental differences impart molecular fingerprints that enable confident petroleum system assignments. Application of the revised paradigm contributed to new Covenant field discovery (Sevier County, UT), and helps open new plays along the Central Rocky Mountain thrust belt.

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