Directory Identifier: GRAVCD-wisc4a
Directory Title: Wisconsin Gravity Data for the Marshfield Area
Principal Investigator: Professor C. Patrick Ervin
Contributing Organization: Northern Illinois University
                           Department of Geology
                           DeKalb, IL 60115

Summary: The gravity station data (8388 records) were compiled by 
Professor Ervin.  This data base was received in April 1993.  
Principal gravity parameters include Free-Air Anomalies and 
Simple Bouguer Anomalies.  Terrain corrections have also been 
computed.  The observed gravity values are referenced to the 
International Gravity Standardization Net 1971 (IGSN 71). The 
gravity anomaly computation uses the Geodetic Reference System 
1967 (GRS 67) theoretical gravity formula.  The data are randomly 
distributed within the area of central Wisconsin between 44 and 45 
degrees north latitude.