Regional Tectonics and Seismicity of Eastern Nebraska, Annual Report, July 1980–June 1981

Authors

R. R. Burchett, University of Nebraska-Lincoln

Date of this Version

11-1981

Citation

Burchett, R. R. 1981. Regional Tectonics and Seismicity of Eastern Nebraska, Annual Report, July 1980–June 1981. NUREG/CR-2411, RA, R6. Nebraska Geological Survey, Institute of Agriculture and Natural Resources, University of Nebraska–Lincoln.

Abstract

This annual report presents and interprets the information obtained by the Conservation and Survey Division (Nebraska Geological Survey) during contract year July 1, 1980, to June 30, 1981, under contract NRC-04-76-3l5 with the U.S. Nuclear Regulatory Commission. The information pertains to the geology, structure, tectonics, and seismicity of eastern Nebraska with emphasis on central Otoe County. Some of the information presented here results from a combination of studies begun in earlier years but the greater part results from studies begun during the contract year.

The scope of the studies is summarized as follows:

1. Rock outcrops in Otoe County were reexamined and reevaluated, and 22 test holes were drilled to determine the altitude of the upper surface of the Elmont Limestone of Pennsylvanian age;

2. One new seismograph was installed in eastern Nebraska;

3. Gravity surveys in eastern Nebraska were extended;

4. Ground magnetic surveys in Otoe County were made and evaluated.

5. Age dating of two Precambrian cores.

Discussion of the results of these studies constitute the remainder of this report.