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Surficial-geologic map of the Eagle A-1 Quadrangle, Fortymile mining district


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The Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted 1:63,360-scale geologic mapping of the Eagle A-1 Quadrangle.The area is part of the 100-year old Fortymile mining district and is located in eastern Alaska near the Alaska-Yukon border. This map illustrates the distribution of a variety of unconsolidated deposits and undifferentiated bedrock in the Eagle A-1 Quadrangle, Fortymile mining district. It was prepared by the interpretation of 1:63,360-scale, false-color, infrared aerial photographs taken from July 1978 through August 1981 and is locally verified by ground observations during field visits.The results should be considered reconnaissance in nature. The dominant unconsolidated deposit is colluvium, [...]


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The purpose of the project was to produce a series of 1:63,360-scale geologic maps for a portion of the Fortymile mining district. The geologic data is important for characterizing and distinguishing between geologic units.Previously published 1:63,360-scale geologic maps of this area have been reconnaissance-level maps or only covered portions of the quadrangle.Mapping at 1:63,360 scale or greater detail is needed to identify critical geologic features that may relate to more regional geologic units. The Fortymile project is part of DGGS's Airborne Geophysical and Geological Mineral Inventory Program (AGGMI), a special multi-year investment by the State of Alaska to produce framework geologic maps that will expand the knowledge base of Alaska's geologic and mineral resources, catalyze future private-sector mineral exploration and development, and guide government agencies' planning.

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