PREFACE

The study of the Whitesail Lake map-area was started as part of a
systematic program. During the course of the work, however, the area came
into unexpected prominence on account of the various projects resulting
from the power developments of the Aluminum Company of Canada. New
exploration was done on the known mineral deposits and active prospecting
led to the discovery of others. Not only, therefore, is geological informa-
tion of timely importance made available by this work, but much informa-
tion was gained from outcrops that have since been buried beneath the
rising waters of the flooded areas. Data from these outcrops may never
again be available.

The mapping clearly showed that the Coast Mountains, by many still
considered to be composed mainly of granitic rocks rarely good hosts for
mineral deposits, are actually underlain by extensive areas of non-granitic
rocks known to contain important orebodies. The Coast Mountains there-
fore contain areas well worth prospecting, and although prospecting is
difficult it is by no means impossible with the aid of modern facilities.

J. M. HARRISON,
Director, Geological Survey of Canada

Ottawa, May 31, 1957

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