Using MT Technologies For Rapid, Cost-Effective and Accurate Detection of Mineralization
As the search for new ore deposits moves ever deeper, both major and junior mining companies are increasingly using MT and AMT for both brownfields and greenfields exploration. INCO's 1991 proof-of-concept study in Sudbury, Ontario started this trend with two AMT sites that sensed a 1750 meter-deep nickel deposit. Falconbridge followed with a feasibility study in 1996 that accurately located two Ni-Cu mineralized zones at ~800 m and ~1350 m.
Since then, Falconbridge has acquired over 2000 MT/AMT sites in the Sudbury basin and elsewhere. In 1999, INCO acquired ~1500 MT/AMT sites at the Voisey's Bay nickel deposit discovered in 1996. Today, thousands of MT/AMT sites are measured every year by worldwide companies, demonstrating the value that industry players place on these techniques.
Tomorrow's mineral discoveries will likely come from depths greater than known ore bodies and may be covered by thick layers of overburden. Finding these deposits requires more sophisticated technology than traditional prospecting methods. Phoenix MT/AMT technology answers that need. MT/AMT is a proven supplement or alternative to expensive traditional approaches like diamond drilling and borehole geophysics and less-costly but shallow-penetrating airborne EM techniques.
Induction vectors (mapped from innovative, rapid 3-H soundings) point to conductive bodies Pseudosections along profile lines show approximate size, depth, location, and strength of conductive anomalies 2-D inversion reveals characteristics such as the high dip angle of this conductor. Plan maps of apparent resistivity and phase highlight conductive bodies at specific depths
Deep Rapid Reconnaissance and Detailed Follow-Up
From near-surface down to any practical drilling depth and beyond, MT allows rapid reconnaissance of areas as large as tens of square kilometers, while detecting conductive zones to 2000 m and deeper.
Closely spaced stations along lines or nets provide data redundancy, high lateral resolution, and a continuous picture of the subsurface resistivity structure.
In a two-pass methodology, station and line spacing are as wide as possible in the first pass to keep cost to a minimum. Once areas of interest have been identified, a second pass with more stations at closer spacing increases resolution. The result is rapid, accurate, and cost-effective identification of conductive zones.
Rapid, Cost-Effective Mapping Of Conductive Zones
Equipment weighs only 30 kg per site, so it's portable by backpack, ATV, snowmobile, or helicopter, from tundra to jungle, in any season. This logistic simplicity reduces cost and increases productivity.
The small footprint and environmentally benign installation make the technique practical almost anywhere.
Flexible site location and offline sensitivity allow meaningful profiles to be constructed without the rigid grid of methods like seismic and IP.
Induction vectors indicate the direction and relative strength of offline conductors and are especially useful where the surface is resistive or frozen (no electrodes required).
MT/AMT sees through the thick conductive clay (impenetrable by airborne or other surface techniques) that covers many prospective areas.