Descriptive, Geologic, and Borehole Geophysical Logs for 23 Test Holes in South-Central Nebraska - Usgs Open-File Report 84-73 (Paperback)

This report presents logs for 23 test holes drilled in eight counties in south-central Nebraska as part of a study of the hydrogeology of the area. Five logs are presented for each of the test holes. The first is a written description summarizing the sediments penetrated during drilling; the second is a geological log providing a diagrammatic representation of the stratigraphic units; the remaining three show spontaneous potential, single-point resistance, and natural-gamma radiation measured in the test holes. The test holes penetrate silts, sands, and gravels of Quaternary age, and siltstones, sandstones, and silts of the Ogallala Formation of Tertiary age. Each test hole was drilled deep enough to penetrate about 20 feet of the underlying Cretaceous-age bedrock.