Candidate: Linda Nicks

Degree of: Doctor of Philosophy

Department: Geosciences

Title: The Glacial Geology of Southern St. Joseph County, Michigan

Committee: Dr. Alan Kehew, Chair
Dr. William Sauck
Dr. Ardith Hansel

Date: Friday, October 29, 2004 9:00 a.m. – 11:30 a.m.
3300 Rood Hall

Abstract: The objective of the dissertation was to map the glacial geology in southern St. Joseph County, Michigan. St. Joseph County was selected because the county has only been mapped at a scale of 1:500,000 and has significant problems involving the surficial geology, including point-source and non point-source contamination of shallow, vulnerable aquifers. The study area lies at the convergence of three lobes of the Laurentide Ice Sheet; the Lake Michigan, Saginaw and Huron-Erie Lobes. The Sturgis Moraine is a prominent ridge transecting the study area. The topography is dissected by southwest-trending channels. The moraine is an important resource in St. Joseph County because of its ability to store and discharge groundwater and supports major streams in the area. The study area consists of a complex succession of coarse-grained sediments (aquifers) and fine-grained tills (aquitards) at depth. All diamictons and till exist in the subsurface and are rarely observed in outcrop. Thick accumulations of sand and gravel in the study area indicate that glacial meltwater deposition played a predominant role in shaping the landscape. The largest contribution from meltwater deposition was from the Saginaw Lobe and the least from the Huron-Erie Lobe indicated by the relative size of the channels and deposits.
This study demonstrates that geophysical techniques such as gamma ray logging of domestic water wells, ground penetrating radar and high resolution seismic were useful tools to identify the lateral extent of aquifers and aquitards for groundwater protection and groundwater modelling and defining the geology at depth.
Two opposing interpretations for the deglaciation of southern Michigan and Northern Indiana: 1) a landform or land system approach and 2) a sedimentologic or geomorphologic approach are presented.

Related Topics

Main List of Archives:
Dissertation Defenses

Current Dissertation Defenses