Geology of the County

In Christian County, water is obtained from consolidated sedimentary rocks of Mississippian through Pennsylvanian age and from unconsolidated sediments of Quaternary age. Geologists call the oldest rocks found at the surface in Christian County the St. Louis Limestone. The most common rocks in Christian County are Mississippian limestones, which were deposited 350 million years ago in the bottom of a warm, shallow sea. At the end of the Mississippian Period, 320 million years ago, the seas receded and sediments of the Pennsylvanian Period were deposited. The warm climate of the Pennsylvanian allowed extensive forests and great coastal swamps to form at the edges of water bodies. Marine waters advanced and receded many times, which produced many layers of sandstone, shale, and coal. Vegetation of all sorts fell into the water and was buried under blankets of sediments, which over long geologic time were compressed into coal. The nonvegetative sediments such as sand, clay, and silt were compressed into sandstone and shale. Over the last million years, unconsolidated Quaternary sediments have been deposited along the larger streams and rivers.

Geologic Formations in the County
Unconsolidated deposits
Alluvium (Qa)

Ste. Genevieve Limestone (Mgl)
St. Louis and Salem Limestone (Mgl)

Caseyville Formation (Pca)

Coals, sandstones, and shales
Tradewater Formation (Pt)

Interbedded limestones, sandstones, and shales
Kinkiad Limestone, Degonia Sandstone, Clore Limestone (Mcu)
Palestine Sandstone (Mcu)
Menard Limestone, Waltersburg Sandstone, Vienna Limestone (Mcu)
Tar Springs Sandstone (Mcu)
Glen Dean Limestone (Mcl)
Hardinsburg Sandstone (Mcl)
Golconda Formation (Haney Limestone, Big Clifty Sandstone, Beech Creek Limestone Members) (Mcl)
Cypress Sandstone (Mcl)
Paint Creek Shale (Mcl)
Bethel Sandstone (Mcl)
Renault Limestone (Mcl)

For more information, see the definitions of geologic terms and rock descriptions, a geologic map of Christian County, a summary of the geology of Kentucky, and a discussion of fossils and prehistoric life in Kentucky.

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