Mine tales: Arizona divided into 3 distinct landforms – by William Ascarza (Arizona Daily Star – July 11, 2016)


William Ascarza is an archivist, historian and author of seven books available for purchase online and at select bookstores.

Arizona can be divided into three physiographic zones, each distinct and unique from the other. They are: the Colorado Plateau, the Arizona Transition Zone and the Basin and Range Province.

The Colorado Plateau in Northern Arizona is the largest portion, covering 42 percent of the state. The Transition Zone in Central Arizona includes 28 percent of the state. The Basin and Range Province in the south encompasses 30 percent of the state.

Ninety percent of Arizona’s population is found in the Basin and Range Province, which includes the large metropolitan areas of Phoenix and Tucson. Parts of the Colorado Plateau and the Basin and Range Province are found in northwestern Arizona.

Basin and Range topography covers northern Mexico along with Arizona, California, Nevada, Utah and part of Idaho. Its parallel mountain ranges, many composed of igneous rock trending north-south or northwest-southeast separated by broad valleys, are one of its key characteristics, along with low elevation, lack of surface water and dryness.

Dryness is brought about by the rain shadow effect caused by California mountain ranges including the Sierra Nevadas, whose western flanks draw upon the majority of moisture from the Pacific, leaving only scattered remnants reaching Arizona except during times of tropical depression. Some mountain ranges differ in pattern.

For the rest of this article, click here: http://tucson.com/news/local/mine-tales-arizona-divided-into-distinct-landforms/article_01feedf1-d772-5e2d-99d6-552a70ed7088.html