The Keystone magnetite occurrence is located in a steep gully, east of Merry Widow Creek.

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 diabase and basaltic intrusive rocks of the Upper Triassic to Lower Jurassic Bonanza Group to the southeast and gabbro to quartz diorite of the Lower to Middle Jurassic Island Plutonic Suite to the west.

The occurrence lies on a west trending fault in Upper Triassic Vancouver Group, Quatsino Formation limestone. The Benson Lake diorite stock of the Jurassic Island Plutonic Suite lies 650 metres west. Intrusive greenstone, thought to be related to the diorite, lies 50 metres east of the occurrence. The occurrence consists of scattered magnetite-skarn exposures. No skarn mineralogy is specified, but at the nearby Raven occurrence (MINFILE 092L 046), garnet, epidote, actinolite, diopside and chlorite are present.

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 2012, 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.