The Pat occurrence is located northeast of Bateman Creek and approximately 6 kilometres southeast of Giscome.
Regionally, the area is underlain by pillow basalts, breccia and tuff with minor sediments of the Mississippian to Permian Antler Formation (Slide Mountain Group) and basaltic volcanic rocks of the Upper Triassic Witch Lake Formation (Takla Group). To the northeast, paragneiss metamorphic rocks of the Upper Cretaceous to Eocene Wolverine Metamorphic Complex and Eocene quartz monzonitic intrusive rocks are exposed.
The dominant rock units encountered in drillholes include a massive, medium- to dark-grey cryptocrystalline limestone; a medium-grey, fossiliferous wackestone to grainstone, with a variety of fossils, including crinoid ossicles and stems, ooids, solitary rugose and colonial corals, brachiopods, bivalves, gastropods and other minor bioclasts; and a carbonaceous, very dark grey unit consisting of interbedded shales, wackestones and grainstones. Occasionally, siliceous breccias were encountered below the limestone and carbonaceous units, some with disseminated sulfide mineralization (usually pyrite and minor chalcopyrite). A high-quality interval in hole PAT06-09, from 88.13 to 130.80 metres, averaged 98.19 per cent calcium carbonate, 0.75 per cent magnesium carbonate and 0.29 per cent silicon dioxide (Assessment Report 29089).
The intent of Graymont Western Canada Inc was to develop lime kilns at the community of Giscome, initially burning 600 000 tonnes per year of limestone to produce 200 000 tonnes per year of lime with production intended for 2010. Graymont had begun technology studies, environmental baseline studies, land agreements and consultations to move the project forward. In December 2007, however, the Company decided to suspend its consultation and environmental assessment process pending clarification of the provincial government’s regulatory intent regarding the production of greenhouse gases (because significant amounts of carbon dioxide are generated in the production of lime).
Work History
In the latter part of 1992 and early in 1993, Dr. Lawrence Halferdahl, on behalf of Ecowaste Industries Ltd. (a wholly-owned subsidiary of Graymont Western Canada Inc), conducted exploration for high-calcium limestone within the vicinity of Prince George. Based upon this exploration, the Pat claims were acquired by staking southeast of Kode-Jerrat Quarry (Giscome MINFILE 093J 025) in 1993.
During 1993, Ecowaste mapped the Pat claims and drilled four NQ holes totalling 347 metres. Additional work during 1994 included a magnetometer survey to assist in defining the contact between carbonates and ultramafic rocks to the northeast, and the completion of four NQ holes totalling 494 metres. After further exploration at the Pat claims, it was concluded that outcrops of limestone on the Pat claims were erosional windows through the Slide Mountain Terrane to the Cariboo terrane below.
In 2005, Ecowaste conducted exploration for high-calcium limestone, as well as a magnetometer survey, on the Pat claims. Exploration consisted of mapping and describing limestone outcrops within the property, whereas the magnetometer survey focused on defining the contact between carbonates and volcanics in the central part of claim Pat 2.
In the summer and winter of 2006, 18 diamond drill holes, totalling 2 489.92 metres, were completed. Core samples were analyzed, and the data compiled to determine the limestone quality and lithologies present in the Pat claim area.
In 2007, all of the Ecowaste claims were converted to the property of Graymont Western Canada Inc for consistency of their British Columbia properties. A review of the 2006 core was completed in the spring of 2007 followed by additional drilling consisting of 3093.5 metres in 16 NQ holes on the Pat claims.
In 2014, Graymont Western Canada Inc. completed nine diamond drill holes, totalling 1844.6 metres, on the Pat claims. Drilling yielded intercepts including 97.77 and 97.95 per cent calcium carbonate over 76.09 and 92.88 metres in holes PAT14-02 and PAT14-03, respectively (Assessment Report 35397). Unclassified reserves are 100 million tonnes of limestone (>95% calcium carbonate, <5% magnesium carbonate) (Information Circular 2015-1, page 11).
