West to East Geologic Cross-Section of the Michigan Basin above the Coldwater Shale.

  • Elevations plotted as feet relative to mean sea level against model column number (1-kilometer spacing).
  • Approximate latitude of cross-section is 44 degrees, on a strike connecting Ludington to Clare, MI (U.S. 10); Clare to Pinconning, MI; and Bayport to Harbor Beach, MI.
  • Horizontal to Vertical Exaggeration = 394 x
  • Aquifer and confining unit elevations constructed from digitally interpolated, hand-drawn structure contour and isopach maps of D.B. Westjohn (see footnotes), and portions of bedrock top and glacial thickness maps of Reick (see footnotes).
  • Structure contour and isopach maps digitally interpolated using WANGRID.FOR by John Hoaglund.
  • Landsurface elevations provided by the MSU Center for Remote Sensing ERDAS database.
  • Great lakes bathymetry digitally interpolated from [NOAA/USGS charts?] using WANGRID.FOR by John Hoaglund.
  • Colored aquifer units include the Glacial Aquifer (Quaternary yellow), Saginaw Aquifer (Pennsylvanian violet), Parma-Bayport Aquifer (Mississippian light blue), and Marshall Aquifer (Mississippian magenta).
  • Interbedded confining units shown in black from top down include Jurassic "red beds" Confining Unit, Saginaw Confining Unit, and Michigan Confining Unit.
  • Base of Marshall sandstone corresponds to the top of the Coldwater Shale (Confining Unit).
    D.B. Westjohn =
    Westjohn, D.B., T.L. Weaver, and K.F. Zacharias, 1994. Hydrogeology of Pleistocene glacial deposits and Jurassic "red beds" in the central lower peninsula of Michigan. U.S. Geological Survey, Water Resources Investigation Report 93-4152, 14 p.

    Westjohn, D.B. and T.L. Weaver, 1996. Hydrogeologic framework of Pennsylvanian and late Mississippian rocks in the central lower peninsula of Michigan. U.S. Geological Survey, Water Resources Investigation Report 94-4107, 44p.

    Westjohn, D.B. and T.L. Weaver, 1996. Hydrogeologic framework of Mississippian rocks in the central lower peninsula of Michigan. U.S. Geological Survey, Water Resources Investigation Report 94-4246, 46 p.

    R.L. Reick = :
    Western Michigan University, Department of Geology, College of Arts and Sciences, 1981. Hydrogeologic Atlas of Michigan. U.S. Environmental Protection Agency Underground Injection Control Program Report, 35 pl., scale 1:500,000