Check out these geology related articles elsewhere on the internet.

Lucas, Spencer G., Vincent L. Santucci, David K. Elliot. 2005. Permian Vertebrates of Arizona. In: Heckert, A.B., and Lucas, S.G., eds., 2005, Vertebrate Paleontology in Arizona. New Mexico Museum of Natural History and Science Bulletin No. 29

Meijer, Arend. 2014. The Pinal Schist of southern Arizona: A Paleoproterozoic forearc complex with evidence of spreading ridge-trench interaction at ca. 1.65 Ga and a Proterozoic arc obduction event GSA Bulletin; September/October 2014; v. 126; no. 9/10; p. 1145–1163; doi: 10.1130/B31002.1; 17 figures; 2 tables; Data Repository item 2014173;published online 18 April 2014.