Powell Formation

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| name = Powell Formation

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| type = Formation

| age = Ordovician

| period = Ordovician

| prilithology = Dolomite

| otherlithology = Shale, sandstone, chert

| namedfor = Powell railroad station (now abandoned), Marion County, Arkansas{{cite journal|last1=Purdue|first1=A.H.|last2=Miser|first2=H.D.|title=Description of the Eureka Springs and Harrison quadrangles|journal=U.S. Geological Survey Geologic Atlas of the United States|date=1916|volume=202|pages=2, 4, 5, 6, 7, 9, 16, 17, 18, 20, 21}}

| namedby = Edward Oscar Ulrich

| region = Arkansas, Missouri and Virginia

| country = United States

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| underlies = Everton Formation

| overlies = Cotter Formation[http://www.dnr.mo.gov/geology/geosrv/ogc/docs/RI-073.pdf Thompson, Thomas L., 2001, Lexicon of Stratigraphic Nomenclature in Missouri, Missouri Department of Natural Resources, Division of Geology and Land Survey, Report of Investigation Number 73, p 230]

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The Powell Formation or Powell Dolomite is a geologic formation in northern Arkansas, southeast Missouri{{Cite web |url=http://www.geology.ar.gov/geology/ozark_ordovician.htm |title=Powell Dolomite/Formation |access-date=2014-07-11 |archive-url=https://web.archive.org/web/20140714131645/http://www.geology.ar.gov/geology/ozark_ordovician.htm |archive-date=2014-07-14 |url-status=dead }} and Virginia. It contains gastropod, cephalopod, and trilobite fossils dating back to the Ordovician Period.