Oil impregnated carbonate rocks of the Timpoweap Member Moenkopi Formation, Hurricane Cliffs area, Utah and Arizona

Oil impregnated rocks crop out at several localities near the Hurricane Cliffs in southwestern Utah and adjacent Arizona. The most significant petroliferous deposits occur in the Timpoweap Member of the Triassic Moenkopi Formation in Timpoweap Canyon and the Hurricane Cliffs south of Hurricane, Utah. The deposits occur in porous carbonate associated with pisolites, oolites, and fossils and may be in an extension of the Virgin Oil Field. A facies analysis of the Timpoweap suggests that it was deposited along the shoreline of the seaway parallel to the present Hurricane Cliffs, and the open sea was to the east. Chert-pebble conglomerate was formed on residual karst topography and as transported grains. Prolific algal growth near the shoreline formed algal carbonate with abundant pisolites; fine-grained dolomite was formed by early diagenesis in more restricted lagoonal and perhaps tidal flat environments; and oolitic and skeletal calcarenite formed as megaripples on the agitated open marine shelf. Although the petroliferous deposits in this report have little economic potential, understanding them may be of value in the search for oil and gas in this region.