The Beaver Cove limestone occurrence is located approximately 3.5 kilometres southwest of Beaver Cove on the southern slope of the Tsulton River. Access is by 15 kilometres of paved road from Port McNeil to Beaver Cove then via logging roads up the Tsulton River valley to the proposed quarry site.
Regionally, the area is underlain by generally northwest-trending and steeply southwest-dipping volcanics and sedimentary rocks of the Upper Triassic Karmutsen Formation (Vancouver Group), Quatsino Formation (Vancouver Group) and Parson Bay Formation (Bonanza Group). To the northwest the sedimentary and volcanic rocks have been intruded by quartz monzodiorite to granodiorite of the Lower to Middle Jurassic Island Plutonic Suite.
Locally, the central and eastern parts of the occurrence area are underlain by grey-white marble, whereas the western part is underlain by black marble of the Quatsino Formation. Bedding measured on site is 124/10 degrees and vertical joints are widely spaced. The contact between the white and black marble is 50 metres wide and is interlayered. Both marbles are fine grained and dense. Trenching at the white marble ballast quarry site defined an area of prospective rock with a radius of approximately 150 to 300 metres.
In 1994, eight diamond drill holes, totaling 188 metres, were placed over an area of 250 by 300 metres. The drilling outlined a large area of white marble just behind the face of the ballast quarry. Some subvertical andesite dikes were found and also a few locations of interbedded white and black marble. Overall the results were encouraging for localizing a stone quarry.
In 2008, South Aggregate Resources collected nine samples from a 250 by 250 metre area of white limestone on the Beaver property. These returned values ranging from 97.53 to 99.65 per cent calcium carbonate with 0.62 to 2.20 per cent impurities (Assessment Report 30481). The focus of their program changed to white limestone for filler applications.
In 2013, a lone sample (140906) of fine-grained black limestone yielded 93.33 per cent calcium carbonate and 1.38 per cent magnesium carbonate with 3.28 per cent insolubles (Assessment Report 35070).
Work History
The site was acquired by staking in 1992 to cover known limestone outcrops and 74 samples were taken for polishing and marketing tests. The site was mapped and prospected in 1992, trenched in 1993 and drilled in 1994. This work outlined a prospective area, centred on an old railroad ballast quarry, for white to grey-white (Carrara Bianco CD) marble and limestone.
In 2008, South Aggregate Resources Inc. completed a program of geological mapping and sampling on the area as the Beaver property. In 2013, Mammoth Geological Ltd. completed a minor program of rock sampling on the area as part of the North Island Carbonate project.
Also, during 2012 through 2019, Graymont Western Canada Inc. completed programs of rock sampling and 561.8 line-kilometres of ground magnetic surveys on the area immediately south of the occurrence as part of the MQ, Nimpkish, Varney Bay and Bonanza properties.
