Geology of the County

In Magoffin County, water is obtained from consolidated sedimentary rocks of the Pennsylvanian Breathitt Formation and from unconsolidated sediments of Quaternary age. The sediments of the Pennsylvanian were deposited 320 million years ago. The warm climate of this period allowed extensive forests to grow and great coastal swamps to develop 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)

Grundy Formation (contains Lee-type sandstone of the former Lee Formation) (Plc)

Coals, sandstones, and shales
Breathitt Group (Pbu, Pbm, Pbl) (Princess Formation, Four Corners Formation, Hyden Formation, Pikeville Formation)

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

Previous--Next--Back to "Groundwater Resources in Kentucky"