Smackover Formation

{{Short description|Geological formation in southeastern U.S.}}

{{Infobox rockunit

| name = Smackover Formation

| image = Smackover Formation areal extent.png

| caption = Wells reporting Smackover Formation tops are indicated by a black point, and extend from Texas to Florida. Formation top depths measured in 6,764 wells range from 1,394 to 23,554 feet.

| type = Formation

| age = Oxfordian

| period = Oxfordian

| prilithology =

| otherlithology =

| namedfor =

| namedby =

| region = Arkansas, Louisiana, Texas, Alabama, Mississippi, and Florida

| country = United States

| coordinates =

| unitof =

| subunits =

| underlies = Buckner Formation

| overlies = Norphlet Formation

| thickness =

| extent =

| area =

| map =

| map_caption =

}}

The Smackover Formation is a geologic formation that extends under parts of Arkansas, Louisiana, Texas, Alabama, Mississippi, and Florida.{{cite web|url=https://www.usgs.gov/news/national-news-release/unlocking-arkansas-hidden-treasure-usgs-uses-machine-learning-show-large|author=U.S. Geological Survey|title=USGS Uses Machine Learning to Show Large Lithium Potential in the Smackover Formation|date=October 21, 2024|accessdate=October 24, 2024}} It preserves fossils dating back to the Jurassic period. The formation is a relic of an ancient sea that left an extensive, porous, and permeable limestone geologic unit.

The Smackover Formation consists of oolitic limestones and silty limestones.{{cite book|last1=Dickinson|first1=Kendell|title=Upper Jurassic Stratigraphy of Some Adjacent Parts of Texas, Louisiana, and Arkansas|date=1968|publisher=USGS|page=E9}}{{cite book|last1=Chimene|first1=Calvin|editor1-last=Braunstein|editor1-first=Jules|title=Upper Smackover Reservoirs, Walker Creek Field Area, Lafayette and Columbia Counties, Arkansas, in North American Oil and Gas Fields|date=1976|publisher=The American Association of Petroleum Geologists|location=Tulsa|isbn=0891813004|pages=177–204}}