Stratigraphic sections and chemical analyses of phosphatic rocks from five trench localities in Weber County, Utah, are presented. Four of the trenches are in Mississippian rocks, and one is in Permian rocks. Of the Mississippian rocks, the highest grade phosphatic interval is at the Wheat Grass Creek locality. Here the phosphatic rocks are 14.9 feet thick, and a 5.8-foot-thick zone has an average of 22.1 percent P2O5. Three localities of Mississippian rocks have 1.1 or less feet of phosphate rock that contains 24+ percent P2O5. The Permian Park City Formation and related strata, Where measured in Hardy Hollow, are 675 feet thick and consist of a 10.9-foot-thick phosphatic interval in the Grandeur Member of the Park City; the Meade Peak Phosphatic Shale Tongue of the Phosphoria Formation is 171 feet thick, but it is cut by numerous faults.
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Stratigraphic sections and chemical analyses of phosphatic rocks of Permian and Mississippian age in Weber County, Utah