The Blackjack (L.1498) occurrence is located on a ridge to the east of the Benson River, approximately 500 metres northeast of Newt Lake.

Regionally, the area is underlain by basaltic volcanic rocks of the Upper Triassic Karmutsen Formation (Vancouver Group), which are overlain sequentially by limestone of the Upper Triassic Quatsino Formation (Vancouver Group); limestone, mudstone and siltstone of the Upper Triassic Parson Bay Formation (Bonanza Group) and mixed volcanic and sedimentary rocks of the Lower Jurassic LeMare Lake volcanic unit (Bonanza Group). The volcanic and sedimentary rocks have been intruded by gabbro to quartz diorite of the Lower to Middle Jurassic Island Plutonic Suite.

At the main occurrence, a narrow rim of Lower Jurassic Bonanza Group volcanic rocks lies between Upper Triassic Vancouver Group Quatsino Formation limestone and diorite of the Lower to Middle Jurassic Island Plutonic Suite. Magnetite is exposed over a width of 15 metres, the lower part being massive blue-black magnetite, grading upward into banded magnetite and limestone that strike northwest and dip 30 degrees west. At its southern limit magnetite mineralization terminates against silicified volcanic rocks.

Two smaller exposures of magnetite lie 100 metres east and 180 metres west of the main showing, respectively.

Lamb (1961) reports a dip needle survey anomaly measuring 240 by 53 metres encompassing the above occurrences. He recognizes two styles of mineralization; 1) massive layers of magnetite replacing limestone and 2) stringers and pods of magnetite in volcanic rocks that separate diorite from limestone.

Jefferey (Minister of Mines Annual Report 1960, page 99) suggests that the emplacement of magnetite was structurally controlled.

Work History

The area has been explored in conjunction with the Merry Widow (MINFILE 092L 044) deposits since the early 1900’s. In 1968, Quatsino Copper Gold completed a program of airborne magnetic and radiometric geophysical surveys on the area. In 1970, Alice Lake Minerals completed an aeromagnetic survey. During 1989, through 1992, Taywin Resources completed programs of geological mapping, trenching and surface sampling on the area. During 2005 through 2011, Grande Portage Resources completed programs of rock, silt and soil sampling, geological mapping, airborne electromagnetic and magnetic surveys and a ground magnetometer survey on the area. In 2016 and 2017, Bridgeland Minerals completed a radar satellite and LiDAR orthophoto geological interpretation program on the area as the Blue Gold/Merry Widow property. In 2019, Mirva Properties Ltd. completed a rock sampling program on the Merry Widow property. In 2020, Roughrider Exploration Ltd. completed a program of rock, silt and soil sampling on the area as the Empire Mine property.