PRECAMBRIAN BASEMENT STRUCTURE MAP OF THE CONTINENTAL UNITED STATES-
AN INTERPRETATION OF GEOLOGIC AND AEROMAGNETIC DATA
By
Paul K. Sims, Richard W. Saltus, and Eric D. Anderson
2008

Scientific Investigations Map 3012

NOTE: This GIS database, identified as SIM-3012, has been approved
for release and publication by the Director of the USGS.  Although
this database has been subjected to rigorous review and is substantially
complete, the USGS reserves the right to revise the data pursuant
to further analysis and review.  Furthermore, it is released on
condition that neither the USGS nor the U.S. Government may be held
liable for any damages resulting from its authorized or unauthorized use.

The database can be downloaded from the USGS server on URL 
http://pubs.usgs.gov/sim/3012/.  In addition, a PDF file of 
the map may be downloaded, from which paper copies may be printed.

The database and other files are as follows:

Readme file--
00readme.txt

Metadata file--
admin_meta.txt
struc_meta.txt
usmag_meta.txt

Shapefiles--
admin.shp
adminUS.shp
adminUSClip.shp
us_structures.shp

Base files--
usmag_hp500.tif
usmag_hp500.tfw