Datil-Mogollon Section

The Datil-Mogollon Section is a physiographic section of the larger Colorado Plateaus province, which in turn is part of the larger Intermontane Plateaus physiographic division.^[1] It is a transitional area between the Basin and Range Province and the Colorado Plateau. It is also a newly defined unit that includes the southern part of the area previously designated the Datil Section.^[2]

Geology

Located along the southeastern rim of the Colorado Plateaus, in New Mexico and eastern Arizona is the Datil section. Most of the Datil section in Arizona is the White Mountain volcanic field. It is an extensive area covered with thick lavas and tuffs. There are also remnants of large stratovolcanoes, mainly composed of basaltic andesite. High tablelands are capped with tuffs, andesite, and basalt lavas, and volcanic-derived conglomeratic sandstones and mudstones. The principal structure of the area is a large central-type volcano called Mount Taylor that rises to 11,389 ft (3,471 m), surrounded by numerous smaller volcanic centers and volcanic necks with extensive lava-covered mesas and valleys to the south. The largest mesa is 46 miles (74 km) long and about 23 miles (37 km) wide with an upper elevation of 1,900 ft (580 m) above the surrounding plain and is capped with about 300 ft (91 m) of lava. The ancient lava flows extend southward into the Mexican Highlands section of the Basin and Range Province and consequently that border of the Colorado Plateaus is ill-defined. Along the eastern edge of the Datil section, the Mexican Highlands section of the Basin and Range province extends northward along the Rio Grande depression to the Southern Rocky Mountains, and the boundary between the depression and the uplifted Colorado Plateaus is sharply defined by the western-most faults of the depression.^[3] It contains several large structural basins and block-faulted ranges. It is bounded on the east by basins of the Rio Grande rift, which are part of the Mexican Highland Section of the Basin and Range Province.^[2]

References

1. ^ "Physiographic divisions of the conterminous U. S.". U.S. Geological Survey. http://water.usgs.gov/GIS/metadata/usgswrd/XML/physio.xml. Retrieved 2007-12-06. 
2. ^ ^{a b} Hawley, John W.. "New Mexico’s Environment, Physiographic Provinces". http://www.nmmastergardeners.org/Pdf%20FILES/NM's%20Environment.pdf. Retrieved 2007-12-25. 
3. ^ Leighty, Dr. Robert D. (2001). "Colorado Plateau Physiographic Province". Contract Report. Defense Advanced Research Projects Agency (DOD) Information Sciences Office. http://www.tec.army.mil/publications/ifsar/lafinal08_01/five/5.1.5_frame.htm. Retrieved 2007-12-25.