Condra, G. E., 1930. Correlation of the Pennsylvanian Beds in the Platte and Jones Point Sections of Nebraska (GSB-3): 57 pp., size 6" x 9". Description: The Pennsylvanian System in the northern part of the Mid-continent region had been under investigation for more than 70 years at the time of this volume. In the beginning, researchers studiedt the most accessible natural exposures; the stratigraphic conditions along broad lines and the major subdivisions of the system. With the development of the oil and gas resources of Kansas, Oklahoma and other states of the Midcontinent, and the need for closer study, the survey activities was made more practical.