The Sierra Anchas are made up of the Precambrian sequence we saw previously at Kearny in our spring Field Geology class. The Jug and Salome Creek expose basal granite, diabase, and cliffs of Pioneer Shale. Above that are cliffs of Dripping Springs Quartzite. The entire sequence is exposed in the actual Sierra Ancha mountains, including Mescal Limestone and Troy Quartzite. Apparently, there are outctrops of Cambrian Tapeats Sandstone (or equivalent) at the tops of some of the peaks in the range.