Homework #3: Geology of the Project Area                                                              Dr. Sanders
Due Tuesday, February 26, 2002

This assignment involves the project that we will be working on for the rest of the semester.  We will construct a numerical model of ground water conditions in a particular area here in Illinois.  To create a successful model of the hydrogeology of the area, we first need an understanding of the geology of the area.  That's what this assignment will help you develop.

The problem is this:  a well is to be installed to supply water for a small community.  In the project, you will construct, test, and use a numerical ground water model that will allow you to delineate a wellhead protection area for that community water supply (CWS) well.  Several of the homework assignments and labs will deal directly with this project.  The final paper will be a report describing the geologic and hydrogeologic setting, the ground water model, and the 5-year recharge area for the well(s) in the study.

The overall assignment is to investigate the geology of the study area and to write a brief report that describes it.  Do this in several steps:

Locate the project study area on a map of Illinois.  The well will be drilled at 41o51’43” N latitude and 88o11’23” W longitude.  Find the topographic map quadrangle(s) that show(s) the study area, and examine the maps to determine what the local topography is.  Also note any geographic or physical features that might be important (streams, lakes, hills, towns, major highways, and so on).

Find the study area on the Geologic Map of Illinois and the map of Quaternary deposits of Illinois (these maps are hanging on the wall in the classroom).  Take notes on the descriptions the maps give of sediments and rocks that occur in the study area.

Examine the other geologic maps and documents provided in class or documents you can find in the library.  Find the study area, and take notes on what the maps reveal.  In your notes, be sure to keep a record of what you learn from each source--in other words, write down the name of the map or document that you got each piece of information from!

Determine the approximate age of each of the geologic formations that occurs at the site.

Sketch a rough cross section that shows what materials are present at the site.  (Later, we will have more site specific data, but for now, just make a rough sketch.)

Considering the major types of glacial deposits (what are they?), decide into which of these major types of deposits the materials at the study area fit.  Considering how each of these is deposited, formulate a hypothesis about the sequence of deposition of geologic materials in the study area.

Write a brief (1-3 pages) description of the geography (location, major geographic features) and the geology of the study area.  It should include a description of the bedrock geology as well as the Quaternary sediments.  Be sure to tell the lithology and age of each formation, as well as the thickness (if you know it) in the study area.  Pay particular attention to the factors that will influence the flow of water through geologic materials in the area.

Last updated February 22, 2002