f Recent geophysical surveys for massive sulphides in the Pyhasalmi area Central Finland

The search for economic Zn-Cu-S- deposits has been going on in the Pyhäsalmi area, central Finland for nearly 30 years . In 1958, when the Pyhäsalmi ore deposit was discovered the studies undertaken by Outokumpu Exploration in the area were given a big boost. immediately after discovery of the deposit, systematic magnetic, EM and gravimetric surveys were started over and in the vicinity of the orebody . The massive pyritic Pyhäsalmi Zn-Cu-S ore causes a distinct gravimetric and electrical slingram anomaly . The ore contains 2 - 4% pyrrhotite ; which greatly improves its electric conductivity . The results of the geophysical survey had a decisive impact on the instruments and methods used in the following search for a massive pyritic zinc ore of the Pyhäsalmi type .