Saturated thickness of the Minnelusa aquifer, Black Hills, South Dakota.

This data set is a polygon coverage created in ARC/INFO that
represents the saturated thickness of the Minnelusa aquifer,
Black Hills area, South Dakota. The unconfined zone of the Minnelusa
aquifer is the area where the potentiometric surface of the aquifer
is below the top of the formation. The elevation of the top of the
potentiometric surface of the Minnelusa aquifer was subtracted from
the top of the Minnelusa Formation, and the boundary of the unconfined
zone was created where the calculation results equalled zero.
The saturated thickness of the aquifer in the zone was determined by
subtracting the elevation of the top of the Madison Limestone from
the potentiometric surface elevation of the Minnelusa aquifer. The
potentiometric surface and the tops of the formation were determined
from water levels and geologic logs from selected wells drilled as of
1998. The thickness coverage contains polygons that have single
integer values representing a range of thickness.