The 'San Juan Basin' is a
drainage basin and geologic
structural basin in the
Four Corners region of the
Southwestern United States; its main portion covers around 4,600 square miles, encompassing much of northwestern
New Mexico, northeastern
Arizona, and parts of
Colorado and
Utah.
As a
drainage basin, the San Juan Basin is defined by the drainage of the
San Juan River and its tributaries, which include the
Animas River and the
Florida River. The San Juan River flows into the
Colorado River.
The drainage of the San Juan River is roughly coincident with the San Juan
structural basin, 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.
The region is notable both by its marked
aridity and by a 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. As the region gently increases in elevation in a southeasterly direction, the Basin's streams flow to the northwest, eventually draining into the
Colorado River.
[1]
Citations
1. Fagan 2005, pp. 41-43.
References
★ .
See also
Uranium mining in the United States