Moorefield Formation

{{Short description|Geologic formation in northern Arkansas and eastern Oklahoma}}

{{Infobox rockunit

| name = Moorefield Formation

| image =

| caption =

| type = Formation

| age = Mississippian

| period = Mississippian

| prilithology = Shale

| otherlithology = Limestone

| namedfor = Moorefield, Independence County, Arkansas

| namedby = George Irving Adams and Edward Oscar Ulrich{{cite journal|last1=Adams|first1=G.|last2=Ulrich|first2=E.|title=Zinc and lead deposits of northern Arkansas|journal=U.S. Geological Survey Professional Paper|date=1904|volume=24|issue=7|pages=26|doi=10.1086/621186|bibcode=1904JG.....12..663.|doi-access=free}}

| region = Arkansas, Oklahoma

| country = United States

| coordinates =

| unitof =

| subunits = Ruddell Shale

| underlies = Batesville Formation

| overlies = Boone Formation

| thickness = up to 300 feet{{cite journal|last1=McFarland|first1=John David|title=Stratigraphic summary of Arkansas|journal=Arkansas Geological Commission Information Circular|date=2004|orig-year=1998|volume=36|page=11|url=http://geology.ar.gov/pdf/IC-36_v.pdf|access-date=2018-06-01|archive-url=https://web.archive.org/web/20161221195953/http://www.geology.ar.gov/pdf/IC-36_v.pdf|archive-date=2016-12-21|url-status=dead}}

| extent =

| area =

| map =

| map_caption =

}}

The Moorefield Formation, or Moorefield Shale, is a geologic formation in northern Arkansas and eastern Oklahoma that dates to the Meramecian Series of the middle Mississippian. In Arkansas, this formation is generally recognized to have one member, the Ruddell Shale, in the upper Moorefield Formation.