Page:Charles R. Fettke - Oil Resources in Coal and Carbonaceous Shales of Pennsylvania (1924).pdf/67

Pennsylvania Geological Survey

A. Photomicrograph of cannel coal, probably Upper Kittanning horizon, country bank of G. W. Currie, two miles north of Nealeys, Pa. A typical humic cannel coal containing almost no spore remains. Magnified 200 times. (Courtesy R. Thiessen.)

B. Photomicrograph of cannel shale, Lower Freeport horizon, from outcrop three-fourths of a mile southeast of Kiskiminitas Junction, Pa. The true nature of the organism which formed the bodies characteristic of this shale is not known. Magnified 200 times. (Courtesy R. Thiessen.)

C. Photomicrograph of oil shale. Chattanooga, Taylor County, Ky. A typical spore shale. Magnified 200 times. (Courtesy R. Thiessen.)

D. Photomicrograph of oil shale, from Green River formation (Eocene), Soldiers Summit, Utah. Magnified 200 times. Courtesy R. Thiessen).