Date of Award
Master of Science
Geological and Environmental Sciences
Dr. Alan E. Kehew
Dr. George Guthrie
Dr. William Sauck
Masters Thesis-Open Access
Seven subsurface glacial diamicton units, including a paleosol, have been characterized from two borings in north-central St. Joseph County, Michigan. These units have been characterized in terms of their clay mineralogy, texture, color, and stratigraphic position. t-Tests confirm that each unit displays a significant difference in mean 7A/10A peak height ratio from all other units.
Unit 4, informally called the Gray Marker tilt has been correlated between borings in this study and to the findings of others (Gardner, 1997, Nicks, in preparation). The Newbury till described by the Indiana Geological Survey (unpublished data) may also correlate to Unit 4, raising the possibility that the Gray Marker till is regionally widespread in the subsurface.
A qualitative clay mineral analysis of the seven diamicton units revealed flaws in the technique of correlating diamictons solely on the basis of 7A/10A peak height ratios. Qualitative clay mineral analysis revealed similarities between the Coldwater Shale and Units 3a, 3b, and 4, suggesting that these units derived much of their clay mineral fraction from the Coldwater Shale. Units 5 and 6 had notably different suites of clay minerals, suggesting a source other than the Coldwater Shale.
Flint, Andrew C., "Stratigraphic Analysis of Diamicton Units in North-Central St. Joseph County, Michigan" (1999). Masters Theses. 4422.