Fig. 6. Map of conductivity in Layer 1, May 1988. (see also page 68)
297
Conduct! vlty
3500
o
US/em
Conductivity
5000
1000
US/em
Fig. 7. Map of conductivity in Layer 2, November 1989. (see also page 68)
Conductivity
4500
1500
/.is/em
Fig. 8. Map of conductivity in Layer 3, November 1990. (see also page 68)