600 
 1950 1955 1960 1965 1970 
876 MINERALS YEARBOOK. 1967 
 
 
 
 
 
 
500 
 
 
 
 
U) 
 
400 
0 
-D 
 
C 
0 
 
 
 
 
 
 
 
300 
 
 
200 
 
 
 
 
100 
 
 
 
 
0 
 
 
 
 
1945 
 
 
 
 
Figure 1.—Value of petroleum, and total value of mineral production
in Wyoming. 
 
 Government Programs.—At the Federal Bureau of Mines, Laramie Petroleum
Research Center Analysis by X-ray diffraction of oil-shale samples from the
lower Wilkins Peak-Tipton section in the Rock Springs 1—3 Corehole
showed that analcite was common to a depth of about 120 feet, then virtually
absent. Below 120 feet montmorillonite occurred continu-~ ously as a common
constituent of the lower half of the Tipton member. Mordenite and 
clinoptilolite appeared in the sections where analcite was absent. Evaluation
of this hole showed discontinuous oil-shale deposits consisting of very rich
and very lean shale in alternating layers. The maximum continuous thickness
of 25-gallon-per-ton shale was only 14.8 feet, which included several 1-foot
samples assaying over 50 gallons per ton. The Laramie station aho continued
research of electrofractui4ng and in-situ retorting of oil shale.