Rock and Land Formations
Butte - A narrow, flat-topped hill of resistant rock with very steep sides. Probably formerly a mesa.
Dana Butte: http://www.grand-canyon.az.us/tr961/sm961106.htm
Breccia - is formed in a very similar fashion to conglomerate. The difference between the two rocks is that breccia's rock fragments are very sharp and angular. These rock fragments have not been transported by water, wind, or glaciers long enough to be rounded and smoothed like in the conglomerate. The cementing agents silica, calcite (CaCO3), and iron oxides are the same as in conglomerate.
Escarpment
Ledges
An open-pit Mine found in the Sonoran Desert
This open-pit mine in the Sonoran Desert near Ajo, Arizona, has exposed an elliptical copper deposit about 1,000 meters long and 750 meters wide. The copper ore mined here is in a bed that averages 150 meters in thickness
Other rock formations and minerals that are found in the Sonoran Desert - http://www.desertusa.com/Thingstodo/geo/geology.html
Geological features - http://www.desertusa.com/mag99/sep/papr/desfeatures.html (including Butte)
Rock Formations