Eagletail Peak, Arizona, USA
U.S. Bureau of Land Management photo (fair use policy)
Eagletail Peak lies in the Eagletail Mountains Wilderness Area, southwest of Phoenix. This part of Arizona consists of large areas of ancient Precambrian rocks and much younger Tertiary volcanic rocks. Complex movements of the crustal plates, accompanied by volcanism, broke up the Precambrian rocks into basins and ranges similar to those in eastern California. I know next to nothing about this mountain. The "feathers" of the peak may represent thick, tilted lava flows or they may result from weathering of thick, faulted metamorphic rocks. Whatever they are, they have given the peak its name, as well as its rugged neighbors in the Eagletail Mountains.
