THIRD YEAR PRODUCTS OF THE NORTH AMERICAN MAGNETIC ANOMALY DATABASE PROGRAM

The Geological Survey of Canada (GSC), U.S. Geological Survey (USGS), and Consejo de Recursos Minerales of Mexico (CRM) are now in the third year of a program to compile magnetic anomaly data into a database and digital map compilation for the North American continent. The resulting integrated, readily accessible, modern digital database spanning North America will be a powerful tool for determining the structure, geologic processes, and tectonic evolution of the continent and can be used to help resolve societal and scientific investigations that span national boundaries. Images derived from the complete digital database will allow a view of continental-scale trends that individual data sets do not provide and link widely separated areas of outcrop and disparate geologic studies. Over the last year, the GSC has collected 250,000 line-km of new data and compiled the magnetic anomaly data for the Arctic Islands. The USGS has collected 83,000 line-km of new high-resolution data and has made significant progress in assembling all magnetic anomaly data into a consistently formatted database. The CRM has flown nearly 295,455 line-km of data as part of a systematic effort to fly much of Mexico with flight lines spaced 1 km apart. The third joint products of the program are compilations of magnetic anomaly data sets of the western and northern parts of North America. A consistent representation of the Earth's magnetic field (International Geomagnetic Reference Field (IGRF)) was removed from each data set. All data sets were analytically continued to the same flight elevation with their datums shifted to match adjacent data. These procedures help to make a seamless map useful for geologic interpretation.