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Nahcolite in the Saline Zone occurs in two major forms: stratiform and nonstratiform. <br />Stratiform nahcolite was deposited directly from lake waters in ancient Lake Uinta. <br />This nahcolite may be either granular (crystalline) or microcrystalline and commonly <br />has interbeds of nahcolitic oil shale, halite and nahcolitic halite. In the nonstratiform <br />type, nahcolite consists of isolated crystals or aggregates of crystals suspended in a <br />matrix of oil shale. This nahcolite resulted from a nucleation-precipitation process <br />that occurred within recently deposited oil shale sediment. <br />Stratigraphic study of the Saline Zone has identified 26 separate, mappable horizons <br />of either stratiform or nonstratiform nahcolite, ranging in thickness from 4 or 5 feet up <br />to more than 30 feet. The thickest and most nahcolitic of these horizons can be <br />considered targets for commercial production of nahcolite. The most important <br />horizons in descending order are the Boies Bed, a 30 to 32-foot thick seam of <br />granular nahcolite in the lower L-5 oil shale zone; the Love Bed, an interbedded <br />series of microcrystalline nahcolite seams and oil shale beds (6 to 7 feet thick) in the <br />L-4 zone; the Greeno Bed, a 7 to 8-foot thick horizon in the R-3 zone consisting of <br />closely packed nahcolite crystals in an oil shale matrix; and the TI Bed, a 7 to 8 foot- <br />thick bed in the L-2 zone that closely resembles the Greeno Bed in texture, <br />composition, and thickness. Other potential nahcolite beds occur in the lower R-5 <br />zone where they are closely associated with stratiform halite (Lower Salt). In each <br />high-grade nahcolite bed the average nahcolite content usually exceeds 60-65 <br />weight percent. Two lower grade beds are located in the upper R-3 oil shale zone, <br />the R-31F and R-3J; both horizons average about 20 feet thick and 40 to 50 weight <br />percent nahcolite. <br />Total gross nahcolite resources for the Lease area are between 4 and 6 billion tons <br />(Brownfield and others, 2009). Of this total, approximately 500 million tons occur in <br />the Boies, Love, Greeno and TI Beds, and in the Lower Salt. Remaining nahcolite <br />occurs either in other thinner and/or leaner nahcolite beds or widely scattered in the <br />oil shale host rock. Oil shale resources for the Saline Zone under the Lease are <br />between 15 and 16 billion barrels (Johnson and others, 2009), while dawsonite <br />resources are about one billion tons. <br />Daub & Associates, Inc. Page 4-4 NSI Mine Plan 2010 Rev. <br />Printed: 7/5/2010 Section 4 Geology