Mineralogy of oil shale in the upper part of Parachute Creek member of the Green River Formation in the Eastern Uinta Basin, Utah

The relative abundance and distribution of major and minor minerals have been determined by X-ray diffraction for samples of Green River Formation oil shale in three drill cores from the eastern part of the Uinta Basin, Utah. The samples in each core are from the same rock stratigraphic interval between the Curly bed and Wavy bed tuffs. This interval includes the Mahogany zone, which is the thickest and richest oil-shale unit with the greatest economic potential for extraction of oil. One core is from Naval Oil Shale Reserve No. 2, another is from Federal Prototype Oil Shale Lease Tract Ua, and the third is from an area nominated for a possible federal oil-shale in situ tract. Dolomite and quartz are generally the most abundant minerals; calcite, albite, and K-feldspar are less abundant. Minor minerals in varied amounts include illite, analcime, aragonite, and smectite. Smectite is abundant in one core and has not previously been recognized in the Mahogany zone. The presence of this mineral is important, in as much as it will increase retorting energy requirements. Saline minerals were not detected.