Paleontology and stratigraphy of the Shady Formation near Austinville, Virginia

The Shady Formation near Austinville, Virginia, approximately 60 miles (96 km) southwest of Roanoke, includes four members. Northwest of the axis of the Austinville anticline, the Shady Formation is entirely of Early Cambrian age, lies stratigraphically above the Erwin Quartzite and stratigraphically below the Rome Formation, and includes the Patterson Member at the base, the Austinville Member, and the Ivanhoe Member at the top. Southeast of the axis of the Austinville anticline, the Shady Formation lies stratigraphically above the Erwin Quartzite; the BiGtterson and Austinville members are present, but the Flatwood Member, named herein, lies stratigraphically above the Austinville Member. The Patterson Member and the Austinville Member contain Lower Cambrian fossils, and the Flatwood Member contains Lower Cambrian and Middle Cambrian fossils. In southeastern sections the Rome Formation is absent and no upper boundary for the Flatwood Member is known. Stratigraphic thicknesses indicate that the Flatwood Member is laterally equivalent to the Ivanhoe Member and to the lower part of the Rome Formation.

Of the 1000 fossil specimens prepared, trilobites are most abundant and were collected from the upper Austinville Member and the Flatwood Member near Clear Branch east and southeast of Austinville. Lower Cambrian fossils were found in the Flatwood Member at and near the Fossil Point locality of Resser (1938), and early Middle Cambrian fossils were found in the Flatwood Member at localities which lie stratigraphically above the Fossil Point localities. Previously the Shady Formation had been considered to be entirely Early Cambrian in age.