I   I


           WEST    ,=                                                                                              EAST
N                                                 <
                 A                        0         Z                                    Z
    CZ           : < -                              3 : o                                 o <                      A '
0         1,000 -<o                                 0 .!                                                             1,0
                       0                                                                   3
           800            ..                     ...                                   . . .                          800
   C                                                                                                                  600
           400400

                                                                                                                      200
           ssea
5rlevel-                                                  'se
           - 0                                                                                                       le v e l
                                                                                                                     -200
        u -400                                                                                                       -400 u_

           -600                                                                                                      -600
                             -60
o          -800                                                                                                      -800
.-1000                                                           -                                                  -1000
o
          -12-12
   '3     -1400
00        - 1600 ,- 1400
                             -1                                                                                       0
          -1800
               Trace of section shown on figure 1                                         Modified from Batten and Bradbury, 1996
    "          Vertical scale greafly exaggerated

                                      EXPLANATION
0o                                                                                              0 1 2 3 4 5 MILES
0.                         Upper aquifer      ........... W ater Table                           ] 111 ,1 , 1 1
       5'                  ~~~~~~(model layer 1)                                                012345KLMTR
                                              (moe lPotentiometric surface in the sandstone aquifer
                           Maquoketa-Sinnipee       (based on 1990 and 1992 data)
                           confining unit
                                               S s General direction of ground-water flow
                        [ Sandstone aquifer
                            (model layer 2)
                            _____I                 Hypothetical well
                            Crystalline rocks (base
                            of ground-water flow
                            system)                Turning point of section


Figure 4. Generalized section showing aquifers, confining unit, and direction of ground-water flow.