undifferentiated rock units

Paleontology and geology

Precambrian rocks in California include igneous and metamorphic basement rocks, as well as some sedimentary rocks (limestone, dolostone, and sandstones, which have often been altered to quartzite). These sedimentary rocks can be found in the White Mountains, Inyo Mountains, and around Death Valley. Most of these rocks do not contain fossils, although some traces and a few fossils have been found in the younger geologic formations of Precambrian age.