Louvicourt

The Louvicourt deposit is a deep VMS deposit located in the Abitibi Greenstone Belt, Canada.

The Borehole Time Domain EM (BHEM) method contributed significantly to its discovery in 1989.

However, the Time Domain EM response is limited to the first and second channels (early times) for the semi-massive pyrite mineralisation. This response is characteristic of a poor conductor.

Because borehole IP is sensitive to the polarisable stringer zone and the sphalerite-rich zones, it can be used to detect massive sulphides at a greater distance than EM methods. 

At Louvicourt, the borehole IP survey was successful because the massive sulphide target is surrounded by a halo of non-conductive, polarizable sulphides.