North Star and Don Jon Mines

"The North Star and Don Jon copper deposits lie beneath the waters of Thompson Lake, which is 12 miles east of Flin Flon, Manitoba. The deposits were discovered during the years 1949 and 1951 by diamond drilling done in the vicinity of pyritic showings on the shores of two small islands in the lake. The Don Jon ore body lies 1, 700 feet southeast of the North Star orebody and is connected with the North Star mine workings by a crosscut on the 600-foot level (Figure 1 ).Production began on January 1, 1955, at a combined rate of 200 tons per day. The ore is trucked, on 24 miles of highway, to the Hudson Bay Mining and Smelting Co., Limited mill at Flin Flon.Regional GeologyRocks in the Thompson Lake area are Precambrian volcanics, ranging in composition from andesite to rhyolite, with related tuffs and breccia. These rocks have a general north-south trend and are steeply dipping. The area is part of the Lac Aimee fault block, which probably is the southward extension of a south-plunging syncline now thrust some miles to the north. This regional deformation has produced many subsidiary zones of intense shearing and crumpling. It is in two of these zones of shearing and drag-folding that the orebodies occur. The only recognizable intrusive is a narrow diorite sill which trends northeasterly near the west shore of Thompson Lake.The North Star MineA pyritic showing, carrying some chalcopyrite, was discovered around the year 1930 on the west side of a small island near the west shore of Thompson Lake. This ground was included in a group of claims acquired by the Hudson Bay Exploration and Development Co., Limited in 1947.In the years 1949 to 1951, a diamond drilling program outlined a copper sulphide orebody. This ore zone comes to surface beneath the lake, about 300 feet north of the pyritic showing on the island."