How can you describe the soil of the blackland prairie

Blackland prairies have a unique characteristic of black and heavy clay soils because of the marine chalks, limestones, and shale that are found in its composition. When soils reach major rivers and tributaries its compositions changes into a more sandy soil. These types of environment are considered to have some of the richest soil in the world where oak, elm, and cedar trees are commonly found.  Blackland prairies have an elevation that ranges from 300 feet to 800 feet above sea level. Its topography is mostly composed of rolling hills and level lands.