The Lafarge Kamloops Cement Plant is mining a rhyolite ash tuff which is used as a silica-aluminate source for the cement manufacturing process. The rhyolite ash is a crystal (quartz, biotite?) clay altered vitric ash which has been quarried in two locations and material shipped to the cement plant east of Kamloops.
The Buse Lake quarry is at the southeast corner of Buse Lake, about 22.5 kilometres east of Kamloops. In this area, the basal unit of the Eocene Kamloops Group is a 300 by 30 metre thick lens of waterlain rhyolite ash which lies unconformably on volcanics of the underlying Upper Triassic Nicola Group. The footwall is a brecciated augite basalt and the hangingwall is a porphyritic greywacke. A dike of younger basalt crosses both the ash tuff and greywacke. On Buse Hill, columnar jointed basalt flows directly overlie the ash.
The rhyolite ash lens strikes 315 degrees and dips 20 degrees northeast. A single assay averages 67.12 per cent silica and 15.78 per cent alumina (Geology, Exploration and Mining in British Columbia 1970, page 513). X-ray diffractograms of untreated and heated (550 degrees Celsius for 1 hour) indicate that the mineralogy of the altered tuff is essentially kaolinite and quartz.
Quarrying sequencing applies to 865,000 tonnes of material divided into two zones (Eastern and Western). Depending on the market conditions or other sources of additive in the process, the quarry would have an active life of either 33 or 58 years (AssessmentReport 24555). Production statistics are not available from 1993 to present.
In 1966, S. Bricka of Lafarge identified the actual area of the quarry as a source of silica-aluminate material; at that time the quarry was a source of ornamental stone. A drilling program of ten holes plus a local surveying scheme helped to put the site into production. Thereafter, at least 44 more holes totalling 2087 metres were bored. The quarry has been in operation since 1970. In 1980, seven diamond-drill holes totalling 611.4 metres were drilled on the Buse claims on behalf of Canada Cement Lafarge Ltd. to delineate the bed of volcanic tuff that is presently being mined. In 1993, Lafarge Canada Inc. re-evaluated previous work done and updated mining and reclamation plans based on the 1981 drilling program.