Seismic Surveys

Knowledge in the Field

Seismic surveys are used in mineral exploration to map the top of bedrock when searching for placer deposits, to locate kimberlites on the basis of their velocity contrast and to define flat to moderately-dipping massive sulphide deposits. Refraction surveys are less expensive per line-km and are the tool of choice in bedrock surveys for placer exploration. They can also be used to screen potential kimberlite targets on the basis of their seismic velocity. Reflection surveys are not normally applied in routine exploration programs on account of the cost per line-km and are more commonly used to detail a deposit during development. 

In the North, permafrost can complicate refraction surveys or render them useless if thawed ground exists beneath frozen ground (velocity inversion).  Reflection surveys are also complicated by permafrost which creates high velocity ground roll. In general, seismic reflection surveys can detect targets at least 20 m deep while refraction surveys can image targets at shallower depths. 

AGL Delivers

At AGL, we are specialists in running efficient small survey programs in areas where access and logistical support are difficult. AGL uses a Geometrics Strataview 48 channel seismograph for mineral exploration surveys, employing explosives, shotgun or hammer sources depending upon the environment. Data processing is performed with Rimrock Geophysics SIP package (refraction surveys) and with SIS Vista (reflection surveys).

 Reflection seismic survey section - Grizzly Deposit (Faro). Ore zone in orange.