Hello, I’m Terry J. Crebs, a retired California-Registered Mining Geophysicist specializing in Helicopter-borne Electromagnetics/Magnetics (HEM) for ore exploration and mineral property evaluation. Please step inside and look around my website.

On the left, I’m interpreting HEM profiles and mapping magnetic-conductors caused by platinum-palladium mineralization in the Stillwater Complex of Montana, USA. This HEM survey established the continuity of a platinum-palladium-rich magnetic-conductors about 250-meters stratigraphically-above the JM-Reef. We named these new magnetic-conductors the Volatile-Enhanced Zones.


To the right is an image of the HEM survey equipment which in 1995 was used to discover the rich world-class massive-sulfide Ni-Cu-Co orebodies at Voisey’s Bay, Labrador, Canada. For this $572K/10,691-km survey, the A-star helicopter flew about 60 meters above the rolling terrain. The smaller magnetic-bird with an optically-pumped magnetometer hung 20 meters below the helicopter, and the larger yellow five-frequency Dighem EM-bird contained three coaxial and two coplanar coil-pairs and hung 30 meters below the helicopter.