The Upper Jurassic-aged Haynesville Shale formation is a dark organic-rich, brittle (conducive to hydraulic fracing) mudstone-shale that lies between the Bossier and Cotton Valley Lime intervals.

Shale, also called mudstone, is a sedimentary rock formed from fine particles such as mud, silt, and clay. Shale is formed by finely bedded material that splits into thin layers. The pieces commonly ...

These formations, known as the Cincinnatian Series, are approximately 200 meters (600 feet) thick and are composed of alternating thin to very thin bedded, gray, fossiliferous limestone and blue-gray ...

Mudstone, shale, and limestone are examples of sedimentary rock likely to contain fossils. As the layers of sediment build up on top of one another, they create a physical timeline. The oldest layers, ...