Brassfield_Formation
The Brassfield Formation, named by A.F. Foerste in 1906, is a limestone and dolomite formation exposed in Arkansas,[3] Ohio, Kentucky, Indiana, Tennessee and West Virginia in the United States.[2] It is Early Silurian (Aeronian, Llandoverian) in age and well known for its abundant echinoderms, corals and stromatoporoids.[4] In Ohio, where the unit has escaped dolomitization, the Brassfield is an encrinite biosparite with numerous crinoid species.[5][6]
- Close view of Brassfield Formation near Fairborn, Ohio, showing grains mainly composed of crinoid fragments.
- Phaenopora superba, a bryozoan from the Brassfield Formation.
- Encrinite from the Brassfield Formation (Silurian) near Fairborn, Ohio.