INTRODUCTION.
The
field studies which form the basis of this report were made by the
writer during July and August, 1906, under the general supervision of
George Otis Smith, of the United States Geological Survey. The writer
wishes to acknowledge the valuable advice and kindly assistance of the
late Prof. Leslie A. Lee, state geologist of Maine, at the time the
field work for this report was done, and the cordial cooperation of
many persons interested in the deposits concerned, without whose aid
these studies, would not have been possible.
The
expenses of the work were shared equally by the Survey Commission of
the State of Maine and the United States Geological Survey.
On
account of the brief time at the writer's disposal in the field, it was
impossible to attempt anything like a prospecting of the whole State
for the minerals here considered. Visits were made, however, to nearly
all of the localities which had been or are at the present time
operated commercially, and numerous observations were made on the
geology of the intervening territory.
With
the exception of a few of the gem deposits, most of the minerals here
described have been exploited commercially only within the past fifty
years. They belong neither to that class of natural resources, such as
coal and limestone, which are useful to a pioneer civilization, nor
(with the exception of the gems) to the class of highly precious
materials which attract the explorer or the adventurer. Their
utilization was possible only after a very considerable development in
the arts and industries of New England had taken place.
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