San Juan Basin
The San Juan Basin is a geologic structural basin in the Four Corners region of the Southwestern United States; its main portion covers around 4,600 square miles (12,000 km2), encompassing much of northwestern New Mexico, southwest Colorado, and parts of Arizona and Utah.
The region is arid with rugged topography of plains and valleys interspersed by buttes, canyons and mesas. Its most striking features include Chaco Canyon (northwestern New Mexico, between Farmington and Santa Fe) and Chacra Mesa. The San Juan Basin also has uplands that exceed elevations of 9,800 feet (3,000 m). Drainage in the structural basin is general westward from the Continental Divide of the Americas to the Mancos River's confluence with the San Juan River. The San Juan River then continues to the Colorado River.
The San Juan structural basin is a large downwarp of sedimentary rocks of mostly Mesozoic age. As a geologic region, the San Juan Basin is noted for its large deposits of coal, uranium, and natural gas. Since the 1980s, the Fruitland Formation in the basin has been one of the major US sources of coalbed methane. In 2007, the San Juan Basin produced 1.32 trillion cubic feet of natural gas, making it the largest source of natural gas in the United States. Uranium mining in New Mexico is also performed from the San Juan Basin.
- "Boundary Descriptions and Names of Regions, Subregions, Accounting Units and Cataloging Units". U.S. Geological Survey. Retrieved 2010-12-27.
- Fagan 2005, pp. 41-43.
- US Energy Information Administration, Top 100 oil and gas fields, PDF file, retrieved 18 February 2009.
- Fagan, B (2005), Chaco Canyon: Archaeologists Explore the Lives of an Ancient Society, Oxford University Press, ISBN 0-19-517043-1