REPORT OF INVESTIGATIONS No. 40


lenses likely cause ionic exchange, resulting in water of altered mineral
content, and the solution of fossil shells in some formations probably con-
tribute to the mineralization. The general area of recharge is outlined in
figure 40 by the low sums of the mineral constituents in parts per mil-
lion. The low mineral content in the recharge area may be due to the
short time of contact between the water and the sand, gravel, and clay.
As the water moves into the aquifer and down and away from the re-
charge area, this mineralization increases. Inset "A" in figure 40 shows


Figure 40. Map of Escambia and Santa Rosa counties showing mineral content of
 water from the sand-and-gravel aquifer.