Decomposed granite of silica sand, silt particles, and clay. Different specific granite types have differing propensities to weather, and so differing likelihoods of producing decomposed granite. The parent granite material is a common type of igneous rock that is granular, with its grains large enough to be distinguished with the unaided eye (i.e., it is phaneritic in texture); it is composed of plagioclase feldspar, orthoclase feldspar, quartz, mica, and possibly other minerals. The chemical transformation of feldspar, one of the primary constituents of granite, into the clay mineral kaolin is one of the important weathering processes. The presence of clay allows water
Granite Wash Pass Granite Wash Pass Granite Wash Pass is a gap between the Granite Wash Mountains and the Little Harquahala Mountains, in La Paz County, Arizona. Granite Wash Pass is located at the southwest end of the Granite Wash Mountains and the northwest end of the Little Harquahala Mountains. The apex of the pass is at an elevation of 1,834 feet/559 meters. The Granite Wash Pass has been a route between the Colorado River and the interior of Arizona from November 1863 when teamsters Gird and Sage discovered a route what became the La Paz - Wikenburg Road through Granite Wash Pass.