The Ste. Genevieve Limestone is a geologic formation

Geologic formation

A formation or geological formation is the fundamental unit of lithostratigraphy. A formation consists of a certain number of rock strata that have a comparable lithology, facies or other similar properties...

 named for Ste. Genevieve, Missouri

Ste. Genevieve, Missouri

Ste. Genevieve is a city in and the county seat of Ste. Genevieve County, Missouri, United States. The population was 11,654 at the 2000 census...

 where it is exposed and was first described. It is a thick-bedded limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 that overlies the St. Louis Limestone

St. Louis Limestone

The St. Louis Limestone is a large geologic formation covering a wide area of the midwest of the United States. It is named after an exposure at St. Louis, Missouri. It consists of sedimentary limestone with scattered chert beds, including the heavily chertified Lost River Chert Bed in the Horse...

. Both are Mississippian

Mississippian (geologic period)

The Mississippian is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earliest/lowermost of two subperiods of the Carboniferous period lasting from roughly 359 to 318 Ma...

 in age and part of the Meramecian series.

Members of the Ste. Genevieve are as follows in descending order:

• Levias Member
• Aux Vases Member
• Joppa Member
• Karnak Member
• Spar Mountain Member
• Fredonia Member

It is a primary producer in the Illinois Basin and has produced commercial oil and gas in Warren County Kentucky. See Kentucky Geological Survey web page http://kgs.uky.edu/kgsweb/PubsSearching/PubResults.asp?dropmenu1=keyword&data1=Genevieve&limiter=AND&dropmenu2=&data2=&yearlmt=nopref&year2=&year3=&pubtype=all&pubSubject=&maps=&submit=submit+search+for+publications&searchtype=criteria
For additional information.