"Two methods of insitu microwave interaction with oil shale are considered for the production of liquid and gaseous fuels. For surface to low-to-moderate depth oil shale strata, high powered highly efficient microwave applicator units would be lowered into spaced 12"" diameter bore holes. Programmed application of the microwave power fractures the shale along bedding planes, couples energy into the moisture contained in the shale, and rapidly decomposes the kerosene into a suitable liquid fuel. A moderate to high heating value gaseous product is also produced in large quantities . The value of the light hydrocarbon gas is enhanced because of the exclusion of diluents such as air which is required in conventional combustion processes both above ground and in conventional insitu. High powered units penetrate the shale and the bedding planes which act as a partial waveguide to propagate the power wave, and the heat-like interaction takes place instantaneously with high intensity close to the applicator and lower intensity, but still effectively, far out into the strata. The combination of increased porosity and rapid decomposition increases the overall hydrocarbon yield over conventional insitu methods that depend on thermal conductivity or combustion. Heat generated at the far reach of the microwave field is used in preheating the shall at the outer region of the next bore hole field. Since heated shale absorbs microwave power more rapidly, increased output results as the process is continued."