Geologic Map of North America

Geologic Map of North America
Name	Geologic Map of North America
Caption	Generalized depiction of lithologies and tectonic provinces across North America
Type	Thematic map
Scale	Variable
Creator	Various geological surveys and institutions
Country	United States; Canada; Mexico

Contents

Geologic Map of North America A geologic map of North America depicts the spatial distribution of rock units, structural fabrics, and tectonic provinces across the United States, Canada, Mexico, Greenland, and adjacent oceanic regions such as the Pacific Ocean, Atlantic Ocean, and Arctic Ocean. These maps synthesize data from national agencies such as the United States Geological Survey, the Geological Survey of Canada, and the Servicio Geológico Mexicano, and integrate regional studies conducted by universities like Harvard University, University of British Columbia, and University of Texas at Austin. They inform research connected to events and regions including the Laramide Orogeny, the Cordilleran belt, the Appalachian Mountains, and the Canadian Shield.

Overview and Purpose

Geologic maps serve to delineate lithologic boundaries, stratigraphic correlations, structural relations, and mineral occurrences for stakeholders including the National Aeronautics and Space Administration, the Environmental Protection Agency, the National Oceanic and Atmospheric Administration, and the World Bank. They support decision-making for industries such as ExxonMobil, Chevron Corporation, Rio Tinto Group, and BHP by indicating resources linked to formations like the Permian Basin, the Williston Basin, and the Athabasca Oil Sands. Maps also underpin hazard assessments involving the San Andreas Fault, New Madrid Seismic Zone, and volcanic centers like Mount St. Helens and Mount Rainier.

Continental-scale mapping partitions North America into provinces such as the Laurentian craton, the Cordillera, the Interior Plains, the Atlantic Coastal Plain, and the Arctic Platform. Accreted terranes include the Insular Superterrane, elements of the Sierra Nevada, and fragments tied to events like the Sevier orogeny and the Taconic orogeny. Offshore provinces encompass the Gulf of Mexico, the Cenozoic volcanic arc of the Aleutians, and the Mackenzie Large Igneous Province.

Maps portray stratigraphic frameworks from Archean cratonic sequences such as the Superior Province and the Slave Province to Proterozoic cover sequences like the Belt Supergroup and Phanerozoic successions including the Paleozoic Appalachian cover and the Mesozoic Western Interior Seaway deposits. Important units include the Niobrara Formation, the Burgess Shale, the Fort Union Formation, and the Kaibab Limestone, with fossil and isotopic ties to collections at institutions like the Smithsonian Institution and the American Museum of Natural History.

Structural synthesis links surface geology to tectonic episodes such as the Grenville orogeny, the Taconic orogeny, the Acadian orogeny, and the Alleghenian orogeny, as well as later rifting events associated with the formation of the Atlantic Ocean and the breakup of Pangaea. Major faults and shear zones mapped include the San Andreas Fault, the Queen Charlotte Fault, the Denali Fault, and the New Madrid Seismic Zone, which relate to plate interactions involving the Pacific Plate, North American Plate, Juan de Fuca Plate, and Cocos Plate.

Techniques combine field mapping traditions from organizations such as the Royal Society of Canada with remote sensing approaches used by NASA and airborne geophysics practiced by vendors contracted by the U.S. Department of the Interior. Data layers derive from satellite missions like Landsat, ASTER, and ICESat, seafloor mapping by NOAA Ship Okeanos Explorer, and borehole data from operators including Schlumberger and Halliburton. Geochronology employs labs such as Lawrence Berkeley National Laboratory and USGS Astrogeology Science Center for techniques like U-Pb zircon dating, Ar-Ar dating, and magnetostratigraphy.

Geologic maps guide resource exploration for entities such as Chevron Corporation, ConocoPhillips, and the Canadian Natural Resources Limited, and underpin water-resource studies conducted by the United States Geological Survey and provincial agencies in Ontario and Alberta. They inform infrastructure projects involving the Panama Canal corridor studies, pipeline routing by companies like TransCanada Corporation (now TC Energy), and environmental assessments required by the Environmental Protection Agency and the International Joint Commission. Hazard mitigation for urban centers such as Los Angeles, San Francisco, Vancouver, and Mexico City relies on these maps.

Major compilations include the continental syntheses by the United States Geological Survey and the Geological Survey of Canada, collaborative atlases such as the North American Commission on Stratigraphic Nomenclature-informed charts, and regional projects like the Alaska Geological Map initiatives, the Gulf of Mexico Seafloor Mapping programs, and the Atlas of Canadian Resources efforts. Academic contributions come from programs at Stanford University, Yale University, University of California, Berkeley, and Massachusetts Institute of Technology, while international partnerships involve the United Nations Educational, Scientific and Cultural Organization and the International Union of Geological Sciences.