By Dan Oancea

 

LITHOPROBE is a Canadian national research project funded by the Natural Sciences and Engineering Research Council (NSERC) of Canada and the Geological Survey of Canada (GSC), Natural Resources Canada. Through seismic reflection, refraction and magnetotelluric methods (data collected along a total of 10 transects across Canada) and multidisciplinary earth science studies of the Canadian landmass and offshore margins it brought a special contribution to the understanding of the genesis and the 4,000 million years evolution of the northern American continent.

The mammoth study provides not only an accurate 3D geotectonic model but also a demonstration of the value of the high resolution seismic reflection method for mineral exploration.

The “Mapping the mantle lithosphere for diamond potential using teleseismic methods” paper proposes a combination of seismic techniques, electrical conductivity and xenolith petrology studies to map the key physical properties within parts of the Slave craton known to host diamonds.

Down under, the seismic tomographic data obtained in the SKIPPY experiment and subsequently, were correlated with GIS and 3D interactive visualization to examine the kimberlite and lamproite intrusions in the “Patterns and controls on the distribution of diamond pipes in Australia” paper.

A cost saving application of seismic reflection at a deposit scale comes from the De Beers’ Snap Lake diamondiferous kimberlite dyke located in Northwest Territories, Canada. An extensive and expansive drilling program has been carried out to delineate the geometry of a dyke sheet which plunges at about 15 degrees to depths greater than 1,300 m and extends over approximate 25 square kilometers. If drilling of the shallower parts of the dyke proved reasonable, not the same could be said about drilling holes for 1,000 m lengths in difficult Arctic ground.

The authors of the “High resolution seismic reflection imaging of a thin, diamondiferous kimberlite dyke” paper proved that seismic reflection techniques, which have been successfully used for the first time to map the diamondiferous intrusion, could provide guidance to the drilling program, even though the interpretation of data could not resolve the dyke thickness limiting its usefulness for mine planning. They are also suggesting that seismic techniques could be used to map the more prevalent kimberlite pipe-host rock contact as an important cost and time saving exploration tool.