Auriferous halos associated with the gold deposits at Lamaque Mine, Quebec

Ec. Polytech., Montreal, PQ, Canada

141 samples. In about 10 percent of the area, the host rocks contain less than 3 ppb Au; this corresponds to normal gold contents in unmineralized greenstone belt igneous rocks (0.6-1.7 ppb Au). The 3-ppb Au contour line encloses a broad area believed to represent an ore-field halo; this threshold value is probably valid for the entire Val d'Or area of northwestern Quebec. The 10-ppb Au contour line envelops all known ore zones and defines ore-zone halos. The ore-zone halo enveloping the Main and East plug orebodies (ca. 4.0 X 10 ⁶ troy oz Au) is extensive (ca. 4 km ² ), while halos enveloping smaller ore zones (0.05-0.2 X 10 ⁶ troy oz Au) are smaller (ca. 0.5 km ² . Ore zone halos do not constitute exact drilling targets; other geophysical or geochemical methods are required to define the structure and attitude of gold-bearing veins within the halos.--Modified journal abstract.

This record provided courtesy of AGI/GeoRef.