THE PINCHI LAKE MERCURY BELT, BRITISH COLUMBIA INTRODUCTION The Pinchi Lake mercury belt is in central British Columbia. The belt is:some 90 miles long and its southern end, at Pinchi Lake, is about 50 miles north of Vanderhoof on the Prince Rupert branch of the Canadian National Railways. In 1936 and 1957 J. G. Gray and the writer mapped the Fort Fraser area’. During the teeole Surv., Canada, Maps 630A and 631A, field season of 1937 cinnabar was discovered by J. G. Gray in the Permian limestones on the north shore of Pinchi Lake where the main showings of the Pinchi Lake mercury mine were later developed. Fol- lowing the publication of Gray's report® claims were staked in the “Gail Surv., Canada, Prel, Paper 58-10. spring of 1938, and later that year were optioned to the Consolidated Mining and Smelting Company.’ Development work revealed cinnabar de- posits of commercial size and grade and a small reduction plant was erected. Production of mercury commenced in June, 1940. Since 1940 additional units have been added to the reduction plant and-it now {April 1942) has a rated capacity of 450 tons a day. The production of mercury from this deposit is far in excess of Canadian require- ments and Canada is able to supply the United Kingdom and the United States with part of their needs, In 1940 and 1941 several other occurrences of cinnabar were found northwest of Pinchi Lake. During 1941 the writer made a geological investigation of the known cinnabar occurrences and of the belt of country in which they are located, The present report sum- marizes the results of this work, The writer is indebted to officials of the Consolidated Mining and Smelting Company, and to Mr. EH. Bron- lund of the Pinchi Lake mercury mine in particular, for their generous co-operation in the work. He also desires to express his appreciation to ‘the prospectors of the district who extended courtesies to him. In the field work the writer was ably assisted ear Messrs. S. A. Kerr, G. R. Hilchey, and J. H. Abrams. PHYSICAL FEATURES ‘The area has an average relief of 1,500 eo 2,000 feet, with occasional mountains rising 3,000 to 3,500 feet above the valley bottoms. The valleys are wide and hold many long lakes, Drift de- posits, chiefly of glacial origin, mantle the timbered slopes and spread out widely and deeply over most of the lowland areas. A large part of the Pinchi Lake mercury belt is occupied by lowland areas and prospecting in them is difficult.