The Nimpkish Limestone (NIM 4) occurrence is located east of Nimpkish Lake and approximately 5.3 kilometres southeast of the north end of the lake.
A northwest trending belt comprised of Triassic Karmutsen Formation volcanics, Quatsino Formation limestone, Parson's Bay sediments/volcanics, all of the Vancouver Group, and overlying Jurassic Bonanza Group volcanic rocks, underlies the area. Regionally, the rocks strike northwest with a shallow 10- to 16-degree dip to the northeast. The majority of the property covers the Quatsino Formation limestone with the other units at the fringe, Karmutsen to the southwest and Bonanza to the northeast. Exposed locally, are the bottom 200 metres of the Quatsino Formation. The limestone comprises three major rock types including: 1) dark-grey, fine-grained bioclastic, micritic lime mudstone with bedding that shows "pillow" (lumpy or nodular) textures; 2) massive, fossiliferous limestone containing abundant "Amphipora" fragments; and 3) calcite grainstone with 0.5 to 2 metres thick beds. Porosity of the limestone is effectively nil.
Intruded into the limestone are dark to light green, dacite to andesite dikes that are typically 1 to 3 metres wide and range from 0.1 to 10 metres across. Thermal alteration of the limestone by the dikes has occurred. Narrow selvages of marble are present and some brecciation of the limestone, up to 10 metres away from the dikes, occurs. Also, silica alteration is present up to 10 metres from the dikes. This is typically seen as silica grains 0.5 to 2 millimetres in diameter. It is speculated that this may be silica replacement of fossil fragments in the limestone. Fieldwork determined that the dikes are sub vertical and trend north northwest.
In 2000, a total of 884 core samples were taken yielding an average composition of, not including dike material, 96.9 per cent CaCO3, 1.3 per cent SiO2 and 0.17 per cent Fe2O3 (Assessment Report 26386).
In 2017, 43 Quatsino samples collected from the Nimpkish property (MINFILES 092L 186 and 092L 349) were highly variable in quality, ranging from 78.35 to 99.68 per cent calcium carbonate, 0.36 to 4.96 per cent magnesium carbonate and 0.05 to 10.21 per cent silicon dioxide (Assessment Report 37354).
Work History
In 1993, Panorama Natural Stone completed a program of geological mapping, geochemical sampling and trenching on the area to the southeast as the Tsult 1-4 claims. The same year, Mammoth Geological completed a program of prospecting on the area to the northwest as the Nimp 1-2 claims. In 1999 and 2000, Eco-Waste Industries Ltd. drilled 22 NQ core holes totalling 2464.3 metres along four section lines oriented across stratigraphy spaced 250 metres apart. Hole depth ranged from 60 to 152 metres. Other exploration programs, during this time, included geological mapping and geochemical sampling on the area as the Nim 4 claim. During 2007 through 2009, Graymont Western Canada completed programs of rock sampling and geological mapping on the area as the Nim 1-18 claims. During 2010 through 2019, Graymont Western Canada Inc. completed programs of prospecting, geological mapping, rock sampling and 561.8 line-kilometres of ground magnetic surveys on the area as part of the MQ, Nimpkish, Varney Bay and Bonanza properties.
