The data was compiled largely from geologic field data collected between 1953 and 1986 by the U.S. Geological Survey and published as 1:250,000 scale geologic quadrangle maps. Additional data for parts of the Wiseman, Ruby, Medfra, and Ophir quadrangles came from 1:63,360 scale quadrangle map published by the Alaska Division of Geological and Geophysical Surveys. This compilation also incorporates unpublished field data.
This data set is also a portion of a statewide geology database, which is being compiled by the U.S. Geological Survey's National Surveys and Analysis (NSA) project, whose goal is to compile geologic, geochemical, geophysical, and other data.
Supplemental attribute tables included with this data set, contain additional descriptive information of each geologic unit. A user may use items SOURCE and CLASS to retrieve information about the original units from which these generalized units were formed.
NOTE: Because of the limitations of common GIS fonts, the letters "Mz", "Pz", "Tr", and "Pa" are substituted for the standard symbols for "Mesozoic", "Paleozoic", "Triassic", and "Pennsylvanian."
Although all data and software published on this web-site have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and (or) the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials.