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
encrinitebiosparite 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.
^
abFoerste, A.F. 1906. The Silurian, Devonian, and Irvine formations of east-central Kentucky, with an account of their clays and limestones. Geological Survey of Kentucky, Bulletin 7, 369 p.
^McFarland, John David (2004) [1998].
"Stratigraphic summary of Arkansas"(PDF). Arkansas Geological Commission Information Circular. 36: 7–8. Archived from
the original(PDF) on 2016-12-21. Retrieved 2018-01-11.
^Schneider, K.A. and Ausich, W.I. 2002. Paleoecology of framebuilders in Early Silurian reefs (Brassfield Formation, southwestern Ohio). Palaios 17: 237-248.
^Ausich, W.I. 1984. Calceocrinids from the Early Silurian (Llandoverian) Brassfield Formation of southwestern Ohio. Journal of Paleontology 58: 1167-1185.
^Coogan, A.H. 1996. Ohio's surface rocks and sediments, in Feldmann, R.M., and Hackathorn, M., eds., Fossils of Ohio: Ohio Department of Natural Resources, Division of Geological Survey Bulletin 70: 31–50.