PLATE 35. Columnar sections of Sharon Springs member of Pierre shale in Wallace and Logan Counties, Kans. 36. Columnar sections of lower part of Pierre shale in Cheyenne, Kiowa, Crowley, and Pueblo Counties, Colo. 37. Columnar sections of lower part of Pierre shale in Las Animas County, Colo. 38. Gamma-ray logs of lower part of Pierre shale and upper part of Niobrara formation in eastern Colorado.