2013-03-01_HYDROLOGY - P2010026 - Laserfiche WebLink

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R5 Zone Hydrostratigraphic Zone The R5 seal is an important hydrostratigraphic zone /seal in the Parachute Creek Member and has been regionally tested to have very low permeability. At the East RDD, the R5 is approximately 40 ' . feet thick. L4 Zone Hydrostratigraphic Zone The 14 hydrostratigraphic zone/WBI is a nahcolite poor mar €stone with thin interbeds of kerogen- bearing rock. Permeability derives primarily from vugs formed by dissolution of nahcotite. It is approximately 450 feet thick at the East RDD. Dissolution Surface The so- called Dissolution Surface separates the currently present and historically present sodium mineral- bearing (nahcolite, dawsonite, and halite) Parachute Creek Member into two major units, the Saline Zone and the overlying Leached Zone. The Dissolution Surface occurs at a depth of 2,013 feet divides the L4 and R4 hydrostratigraphic zones at the East RDD Project Site. - The Dissolution Surface also marks the interface above which free ground water exists and below which no free ground water occurs due to the presence of unleached saline minerals. The Leached Zone is the result of dissolution of soluble saline minerals by downward percolation of ground water. The Saline Zone Is a complex array of bedded and non - bedded nahcolite with local occurrences of bedded halite deposits. R4 Seal Zone The R4 seal zone spans the stratigraphic Interval from the base of the Dissolution Surface to the top of the Wasatch Formation. The dominant feature of the seal is the presence of nahcolite that occupies the available porosity. The target interval for activities related to the East RDD is within the R4 seal as defined. Hvdrostratlaraphrc Unit - Top (ft)* Base (ft)* - - TDS (ma /j) - - Lit 71 oloav Uinta 0 944 710 -1,000 sandstone /siltstone Green River - R8 944 •1,004 oil shale Green River - A Groove 1,004 1,118 830 - 850 maristone Green River- R7 1,118 1,180 oil shale Green River - B Groove 1,180 1,341 710 - 770 maristone Green River- R6 1,341 1,381 oil shale Green River - L5 1,381 1,523 700 - 710 maristone Green River - R5 1,523 1,563 oil shale Green River - L4 1,563 2013 45,000 maristone Green River - R4 Seal 2013 2,654 nahcolite cemented oil shale and maristone Top of Wasatch 2,654 many shale *estimated top and base of formations are estimated from the OB04(SAW) well except where noted 'estimated base of formation estimated from nearby projects Permit CO32210 -00000 TABLE 2.1 GEOLOGIC SETTING 7 FINAL PERMIT Statement of Basis