Mar. 09, 1998

   -- Final Grid Data -- USGS, Tucson, Arizona, 1997

The grids are in gxf format with relevant information contained
in a header.  The following grids used to create the plotted contours
are included:

TMIGRD.GXF - Levelled and decorrugated total magnetic intensity
MAGGRD.GXF - Unlevelled total magnetic intensity
RAGRD.GXF  - Radar altimeter

:----------------------------------------------------------

A sample of the header is shown below:


                  TUCSON, ARIZONA - USGS, 1997
                  TOTAL MAGNETIC INTENSITY
                  UTM GRID ZONE 12N, DATUM WGS-84
                  SANDER GEOPHYSICS LTD, MARCH 09, 1998
#POINTS
1041
#ROWS
1381
#PTSEPARATION
50
#RWSEPARATION
50
#XORIGIN
490000
#YORIGIN
3510000
#DUMMY
-9999.000
#SENSE
1
#GRID

:----------------------------------------------------------

Data acquired and compiled by:

Sander Geophysics Ltd.
260 Hunt Club Rd.
Ottawa, Ontario, K1V 1C1
Canada

phone: 613-521-9626
fax:   613-521-0215
email: info@sgl.com