Terry J. Crebs
California-Registered Geophysicist #975
Lakewood, Colorado USA

“Reading between the mines for over 40 years.”


About My Business

I am a retired freelance exploration geophysicist that specialized in helicopter-borne electromagnetics/magnetics (HEM) geophysical surveys for nickel, copper, cobalt, platinum-group metals (PGMs), and diamonds.

Mafic and ultramafic rocks host almost all of the world’s PGMs, diamonds, and sulfide-nickel. I usually focused on these types of rocks. Anorthosite suites with olivine-rich troctolites are my passion.

As Chief Geophysicist for Diamond Fields Resources, Inc., I spotted Borehole #DDH-7 in Jan-1995. This was the discovery borehole for the +32-million-metric-tonne “Ovoid” Ni-Cu-Co orebody at Voisey’s Bay, Labrador, Canada.

Services and Products

I believe that the best way to QC (quality control) an airborne geophysical survey (and find new ore) is to interpret the daily analog profiles. If on-site, I would tune the survey specifications to optimize mineralization mapping and detection.

I sometimes found the world-class orebodies that less-experienced explorationists would miss. Employing the best acquisition and processing geoscientists, I interpreted the processed geophysical data and then drilled/confirmed the orebodies.

I usually worked for mining or exploration companies. I recommended survey specs, got bids from contractors, and made recommendations about timing and methodology that were best suited for the target mineralization.

Once I had interpreted the survey, I would usually recommend some ground-based follow-up. However, I often prefer to spot boreholes from the airborne survey because these data often have less ground and topographic “noise”.