GAAR Surficial Geology

This group layer is based on helicopter-supported surficial geologic field mapping of the central Brooks Range and its foothills during the summers of 1975-1987. The mapping comprised ten 1:250,000 quadrangle sheets plus part of one additional sheet. Those parts of the individual maps that occur within the Gates of the Arctic National Park and a 10-mile peripheral buffer zone have been compiled into the accompanying map sheet, and descriptions of each map unit have been revised to make them applicable to the Park as a whole. Some units that occur rarely, especially if small in size and present only at extreme margins of the Park, have been merged with other more common units. Although the map is intended to be a useful overall guide to the surficial geology of the Park and its immediate surroundings, individuals desiring more information on specific areas will find further useful data accessible by specific quadrangle in a database maintained by the U.S. National Park Service or in the published U.S. Geological Survey geologic maps listed below the index map.