The Shawnee Hills is a region of

southern Illinois Southern Illinois, also known as Little Egypt, is the southern third of Illinois, principally along and south of Interstate 64. Although part of a Midwestern United States, Midwestern state, this region is aligned in culture more with that of th ...

that rests mainly in an east-west arc roughly following the outline of the southern end of the

Illinois Basin The Illinois Basin is a Paleozoic depositional and structural basin in the United States, centered in and underlying most of the state of Illinois, and extending into southwestern Indiana and western Kentucky. The basin is elongate, extending app ...

. Whereas Mississippian and

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

Age rock layers are deep beneath the soil surface in central Illinois, these strata pierce the surface in southern Illinois. The Shawnee Hills are surface expressions of the more weather-resistant limestone and

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

layers. This formation is due in part to the last glaciation of the Ice Age (which tended to grind down hills and bury them under soil) not reaching this far south.

Shawnee The Shawnee are an Algonquian-speaking indigenous people of the Northeastern Woodlands. In the 17th century they lived in Pennsylvania, and in the 18th century they were in Pennsylvania, Ohio, Indiana and Illinois, with some bands in Kentucky a ...

is the name used for a native American people, who historically resided in the

Ohio Valley The Ohio River is a long river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing southwesterly from western Pennsylvania to its mouth on the Mississippi River at the southern tip of Illinoi ...

. The Shawnee Hills are often called the "Illinois Ozarks", especially in promotional literature for tourism. But they are technically not a part of

The Ozarks The Ozarks, also known as the Ozark Mountains, Ozark Highlands or Ozark Plateau, is a physiographic region in the U.S. states of Missouri, Arkansas, Oklahoma and the extreme southeastern corner of Kansas. The Ozarks cover a significant portio ...

, a geologically similar area that for the most part begins just to the west across the

Mississippi River The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it f ...

floodplain in southeastern

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

. Within the Shawnee Hills,

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

is extensively quarried from outcrops, while both north and south of the Shawnee Hills, coal is mined by surface techniques on shallow coal seams near the edges of the Illinois Basin and by deep mining techniques in the deeper parts of the Basin. Additionally, extensive faulting in and around the Shawnee Hills occurred due to deep

tectonic Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents k ...

activities and formed sites for deposition of

fluorite Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF2. It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon. The Mohs sca ...

, a mineral used for production of the element fluorine. At one time, about 80% of the world's fluorspar ore was mined near the towns of Rosiclare, Illinois, Rosiclare and Cave-In-Rock, Illinois, Cave in Rock. A large portion of the Shawnee Hills lies within the Shawnee National Forest. The beauty of the Shawnee Hills, the Shawnee National Forest, and the Ohio River Valley make the area a prime tourist destination. The Shawnee Hills can be seen faintly from as far north as Vergennes, Illinois, Vergennes. The westernmost portion of the hills rise south of Murphysboro, Illinois, Murphysboro and continue southward to Olive Branch, Illinois, Olive Branch. Large plains used for farmland separate the hills from the Mississippi River along Illinois Route 3, especially near the towns of Wolf Lake, Illinois, Wolf Lake, Grand Tower, Illinois, Grand Tower and Ware, Illinois, Ware. The Big Muddy River cuts through the hills south of Kinkaid Lake, making rocky cliffs that can be viewed by boat-ride down the river.

References

{{coord, 37, 30, N, 88, 40, W, display=title Geology of Illinois Southern Illinois Landforms of Illinois

See also

References