Due to uplift during the Taconic orogeny, the sea retreated and Arizona returned to continental conditions during the Ordovician and Silurian leaving few rocks from these time periods. During the Devonian, Arizona alternated between marine and continental conditions, as a subduction zone and volcanic island arc appeared in the area of Nevada. The Martin Formation in southern Arizona contains limestone, sandstone, shale and chert deposited in the Late Devonian and laden with fish and invertebrate fossils.
