Part of a series on exploration and Mining
I grew up in a gold mine. Discovery Mine north of Yellowknife. Located at 63 Degrees 10' 00" North by 113 degrees 50' 02" West.
Discovery is located in a very ancient belt of rock called the Precambrian Shield. There was once (three to eight hundred million years ago) a gigantic range of mountains possibly rivaling the Himalayas, in that time erosion has worn them down to nearly a level plain with small hills and valleys. For up to two hundred thousand years the area was covered in glaciers up to ten thousand feet thick. When these retreated nearly 50,000 years ago nearly all the dirt had been scraped and eroded away leaving bare rock and swamp/muskeg. Water pools in every hollow and lakes abound. I think there are more lakes in the Precambrian Shield than the rest of the world combined.
The rocks in the area are called sediments because at one time, they were clay particles which were deposited in an ancient sea some two to four hundred million years ago. There were two to three miles deposited and then came a period of intense volcanic activity combined with earthquakes. The clay beds turned into limestone and were twisted and heaved. In the case of Discovery they were turned on edge 90 degrees from horizontal. The limestone was turned into a hard grey rock called Argillite by heat and pressure. The rock was shattered in places and molten rock was forced in from below. It was a white to grey rock called quartz and contains gold. This took place multiple times over a long period and gold was found in commercial quantity all through the area.
Gold was discovered here at Discovery Consolidated mine in 1944 by the Giauque family from Eston Sask. In 1945 diamond drilling was started looking for hidden deposits in surface quartz vienlets in altered andesite. Some high grade intersections were obtained Norm Burns was engaged to carry out investigations from the x-ray program. During the Fall the now famous North Zone dragfold quartz vein was discovered. The first vein at the initial site was shaped like a horseshoe and was of high grade. ranging from one & a half to eighteen feet wide and about four hundred plus feet long with an initial grade in excess of 3oz of gold per ton. The Discovery property was 2,600 ft. long.