Skip Links

USGS - science for a changing world

U.S. Geological Survey Scientific Investigations Map 3125

In Cooperation with the National Park Service

Surficial Geologic Map of the Gates of the Arctic National Park and Preserve, Alaska

By Thomas D. Hamilton and Keith A. Labay


The Gates of the Arctic National Park and Preserve (GAAR) is centered over the central Brooks Range of northern Alaska. To the west, it abuts the Noatak National Preserve; its eastern boundary is the transportation corridor occupied by the Dalton Highway and the Alyeska Pipeline. The GAAR extends northward beyond the northern flank of the Brooks Range into the southern Arctic Foothills. Its southern boundary lies beyond the south flank of the Brooks Range within foothills and depositional basins of interior Alaska. The accompanying surficial geologic map covers all of the GAAR with the addition of a 10-km (6.2-mi) belt or “buffer zone” beyond its boundaries. A narrower (5-km) buffer zone is employed where the GAAR extends farthest north and south of the Brooks Range, in the north-central and southwestern parts of the map area, respectively.

The surfical geologic map incorporates parts of ten surficial geologic maps previously published at 1:250,000 scale. In addition, a small part of the buffer zone mapped in the southwest corner of the map area was compiled from unpublished surficial geologic mapping of the Shungnak 1:250,000-scale quadrangle. Each of those individual maps was developed from (1) aerial and surface observations of morphology and composition of unconsolidated deposits, (2) tracing the distribution and interrelation of terraces, abandoned meltwater channels, moraines, abandoned lake beds, and other landforms, (3) stratigraphic study of exposures along lake shores and river bluffs, (4) examination of sediments and soil profiles in auger borings and test pits, and exposed in roadcuts and placer workings, and (5) analysis of previously published geologic maps and reports. The map units used for those maps and employed in the present compilation are defined on the basis of their physical character, genesis, and age. Relative and absolute ages of the map units were determined from their geographic locations and from their stratigraphic positions and radiocarbon ages.

Thumbnail of and link to report PDF (21.4 MB)

Last modified September 4, 2012
First posted March 20, 2012

         Files for viewing and printing:

  • Pamphlet PDF (19 pages, 6.8 MB)
  • Sheet PDF (55.7 x 39.0 inches, 22.6 MB)


  • Readme PDF (143 kB)
  • Metadata TXT (61 kB)
  • GIS database ZIP (184 MB, compressed; 657 MB, expanded) Expands to a folder named GAR_GIS_Web. This GIS database contains all the geologic information used to publish the map.
  • Ancillary export files ZIP (8.2 MB, compressed; 35.6 MB, expanded) Contains export files (e00 format); these ancillary files are not included in the GIS database.
  • This report is also available in print (print version does not contain the database) from:

    USGS Information Services, Box 25286,
    Federal Center, Denver, CO 80225
    telephone: 888 ASK-USGS; e-mail:

For additional information contact:
Alaska Science Center staff
U.S. Geological Survey
4210 University Dr.
Anchorage, AK 99508
Alaska Science Center

This report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.

Suggested citation:

Hamilton, T.D., and Labay, K.A., 2011, Surficial geologic map of the Gates of the Arctic National Park and Preserve, Alaska: U.S. Geological Survey Scientific Investigations Map 3125, pamphlet 19 p., scale 1:300,000, available at

Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Contact USGS
Page Last Modified: Thursday, December 01, 2016, 05:24:59 PM