Publication Date
1966
Document Type
Dissertation/Thesis
First Advisor
Odom, J. Edgar
Degree Name
M.S. (Master of Science)
Legacy Department
Department of Geology
LCSH
Geology--Illinois--Du Page County
Abstract
The elevation of the bedrock surface and the thickness of the glacial drift in a fire square mile area in southwestern Dupage County, Illinois, were mapped in detail from data obtained by means of a hammer seismograph. Bedrock deaths and drift thicknesses determined by seismic methods showed a correlation coefficient of +0.97 with information from wells and sewer test-borings used as a control group. Silurian dolomite is known to compose the bedrock in the area. The topography of the bedrock surface and the present-day topographic surface are quite similar. The drainage system on the bedrock surface appears to be joint controlled. No major karst features were mapped in the area. Variations in seismic velocities within the glacial drift indicate that the drift is composed of a sandy, gravelly layer overlain by a silty clay till. A sons of saturation may have influenced the drift velocities and may also be related to the "weathered" tone. A ten foot contour interval was considered ae the most reliable interval for mapping the bedrock surface. The 95% confidence interval placed the seismic control points within 3.68 feet above and 0.12 feet below the bedrock surface established by well and boring control points. The hammer seismograph is considered a practical and economical means of obtaining accurate depths to bedrock in areas of drift cover of lees than fifty feet.
Recommended Citation
Johnson, Donald O., "A geophysical investigation of the bedrock surface in southwestern DuPage County, Illinois" (1966). Graduate Research Theses & Dissertations. 343.
https://huskiecommons.lib.niu.edu/allgraduate-thesesdissertations/343
Extent
v, 59 pages
Language
eng
Publisher
Northern Illinois University
Rights Statement
In Copyright
Rights Statement 2
NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.
Media Type
Text
Comments
Includes bibliographical references (pages [31]-32)