Carters Limestone

{{Short description|Geologic formation in Tennessee, USA preserving fossils from the Ordovician period}}

{{Infobox rockunit

| name = Carters Limestone

| image =

| caption =

| type = Formation

| age = Middle Ordovician

| period = Middle Ordovician

| prilithology = Thin-bedded to massive limestone

| otherlithology = Thin shale and bentonite beds

| namedfor =

| namedby = J. M. Stafford

| region = Central Basin, Tennessee

| country = United States

| coordinates =

| unitof = Lower and Upper Members

| subunits =

| underlies = Hermitage Formation

| overlies = Lebanon Limestone

| thickness = {{convert|9|-|28|m|ft|abbr=on}}

| extent = Central Tennessee

| area =

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The Carters Limestone is a geologic formation in Tennessee. It preserves fossils dating back to the Ordovician period.{{Cite web |title=Geolex — Carters publications |url=https://ngmdb.usgs.gov/Geolex/UnitRefs/CartersRefs_890.html |access-date=2025-01-02 |website=ngmdb.usgs.gov}}{{Cite web |title=Tennessee Fossils |url=http://tennesseefossils.com/Formations/MT%20-%20Carters.php |access-date=2025-01-02 |website=tennesseefossils.com}}{{Cite web |title=NPS Geodiversity Atlas—Chickamauga & Chattanooga National Military Park, Georgia and Tennessee (U.S. National Park Service) |url=https://www.nps.gov/articles/nps-geodiversity-atlas-chickamauga-chattanooga-national-military-park-georgia-and-tennessee.htm |access-date=2025-01-02 |website=www.nps.gov |language=en}} The Carters contains abundant invertebrate fossils, including corals, stromatoporoids, brachiopods and bryozoans, mollusk (gastropods, bivalves and orthoconic cephalopods) and trilobites. Trace fossils also occur. The unit has several volcanic ash (bentonite) beds and is known to have isolated reef development.