Scale: 1 pixel = 1 km. 10-degree grid; Lambert Conformal Conic Projection, Center 62N 150W
Legend
The Alaska Maps are excerpted from the Geologic Map of North America (1:5,000,000) and are less detailed than other maps.
Sparse as the road net in Alaska is, the Alaska Pipeline highway extends across the state near the center and therefore there is a highway map for every sheet.
Symbols (U.S.)
Periods
Q Quaternary 2 Ma - 0
Qh Holocene 10 Ka - 0
Qp Pleistocene 2 Ma - 10 Ka
T Tertiary 65 - 2 Ma
Tp Pliocene (Neogene) 5-2 Ma
Tm Miocene (Neogene) 23-5 Ma
To Oligocene (Paleogene) 33-23 Ma
Te Eocene (Paleogene) 55-37 Ma
Tx Paleocene (Paleogene) 65-55 Ma
K Cretaceous 145 - 65 Ma
J Jurassic 208 - 145 Ma
Tr Triassic 245 - 208 Ma
Pm Permian 286 - 245 Ma
P Pennsylvanian 320 - 286 Ma
M Mississippian 360 - 320 Ma
D Devonian 408 - 360 Ma
S Silurian 428 - 408 Ma
O Ordovician 505 - 428 Ma
C Cambrian 570 - 505 Ma
Z Precambrian Z 900 - 570 Ma
Y Precambrian X 1600 - 900 Ma
X Precambrian Y 2500 - 1600 Ma
W Precambrian W 4600 - 2500 Ma
Combinations of symbols refer to transitional or undivided units. For exampleDS refers to undivided Devonian and Silurian rocks.
References
Principal sources for data. Links, even those of government agencies, go out of date quickly and are mostly not provided. Search by title and publication number to find links to data.
Conterminous US Geology
US Geological Survey: Mineral Resources; Geology of the conterminous United States. A digital version of the Geologic Map of the United States, originally published at a scale of 1:2,500,000 (King and Beikman, 1974b). Excludes Alaska and Hawaii. Be sure to spell Beikman correctly when searching.
Detailed Geology of States
US Geological Survey: Mineral Resources: Online Spatial Data; Geologic maps of US states
US Bouguer Gravity
US Geological Survey: Mineral Resources; Online Spatial Data; Gravity anomaly grids for the conterminous US
US Isostatic Gravity
US Geological Survey: Mineral Resources; Online Spatial Data; Gravity anomaly grids for the conterminous US
US Magnetic Anomalies
US Geological Survey: Digital data grids for the magnetic anomaly map of North America: Open-File Report 02-414
Digital Aeromagnetic Datasets for the Conterminous United States and Hawaii - A Companion to the North American Magnetic Anomaly Map, U.S. Geological Survey Open-File Report 02-361
Digitized Aeromagnetic Datasets for the Conterminous United States, Hawaii, and Puerto Rico, U.S. Geological Survey Open-File Report 99-0557
Canada Geology
Wheeler, J.O., Hoffman, P.F., Card, K.D., Davidson, A., Sanford, B.V., Okulitch, A.V., and Roest, W.R. (comp.) 1997: Geological Map of Canada, Geological Survey of Canada, Map D1860A.
Canada Bouguer Gravity and Magnetic
Natural Resources Canada; Earth Sciences Sector; Geoscience Data Repository
Magnetic Anomalies outside US
US Geological Survey: Digital data grids for the magnetic anomaly map of North America: Open-File Report 02-414
Offshore Geology
Mostly from US Geological Survey; Resources for the Geologic Map of North America; GIS Files (shapefiles); (ESRI geodatabase only is USGS DR-424)
Western Mexico Geology
US Geological Survey; Resources for the Geologic Map of North America; GIS Files (shapefiles); (ESRI geodatabase only is USGS DR-424)
Eastern Mexico and Gulf of Mexico Geology
US Geological Survey OFR 97-470-L; Map Showing Geology, Oil and Gas Fields, and Geologic Provinces of the Gulf of Mexico Region; Digitally Compiled by Christopher D. French and Christopher J. Schenk
Caribbean Geology
US Geological Survey OFR 97-470-K; Map Showing Geology, Oil and Gas Fields, and Geologic Provinces of the Caribbean Region; Digitally Compiled by Christopher D. French and Christopher J. Schenk
Hearn, P., Jr., Hare, T., Schruben, P., Sherrill, D., LaMar, C., and Tsushima, P., 2001, Global GIS Database, Digital Atlas of Central and South America: U.S. Geological Survey Digital Data Series DDS-62-A. [on-line] available at: http://webgis.wr.usgs.gov/globalgis/
U.S. Geological Survey World Energy Assessment Team, 2000, U.S. Geological Survey World Petroleum Assessment 2000: U.S. Geological Survey Digital Data Series DDS-60, 4 CD-ROMs. [on-line] available at: http://pubs.usgs.gov/dds/dds-060
Arctic Offshore and Greenland
Maps showing Geology, Oil and Gas Fields, and Geologic Provinces of the Arctic; Compiled by Feliks M. Persits and Gregory F. Ulmishek; U.S. Geological Survey Open File Report 97-470-J
Ocean Floor Isochrons
Muller, R. D., M. Sdrolias, C. Gaina, and W. R. Roest (2008), Age, spreading rates, and spreading asymmetry of the world's ocean crust, Geochem. Geophys. Geosyst., 9, Q04006, doi:10.1029/2007GC001743. On-line through NOAA; Age, spreading rates and spreading symmetry of the world's ocean crust (Version 3, September 2008) Contoured using Global Mapper 14.