Engineering - geologic map of the Eagle A-2 Quadrangle, Fortymile mining district, Alaska

The Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted 1:63,360-scale geologic mapping of the Eagle A-2 Quadrangle (270 square miles; equivalent to four 7.5-minute quadrangles). 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 potential near-surface sources of various geologic materials that may be useful for construction. Field observations indicate that each geologic unit (for example, stream alluvium) has a definite composition or range of composition. Therefore, the probable presence of materials is interpreted from the distribution of geologic units on the geologic map of this quadrangle. This map is generalized and is not intended to show exact locations of specific materials. Local variations are common, especially near unit boundaries. The map was derived electronically from the geologic map of the area using Geographic Information System (GIS) software. It is locally verified by ground observations during field visits. The results should be considered reconnaissance in nature.