The Crawford Upland of

Southern Indiana Southern Indiana is a region consisting of the southern third of the state of Indiana. The region's history and geography has led to a blend of Northern and Southern culture distinct from the remainder of Indiana. It is often considered to be p ...

, United States. The eastern section of the

Indiana Uplands The Indiana Uplands or the Hoosier Uplands are a geographical region in south-central Indiana. On a topographical map the Indiana Uplands begin slightly north of the city of Martinsville, Indiana and continue south to the Ohio River. The descript ...

, this region contains the hilliest terrain in the state caused by the outcropping of

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 ...

units at the surface. In some areas erosion cuts through the sandstone layers completely and exposes underlying

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 wh ...

s. The exposure of limestone at the surface in the Crawford Upland results in the formation of

caves A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

, dolines, and other surface expressions of karst topography. The alternating sandstones, limestones, and

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especia ...

of the

West Baden West or Occident is one of the four cardinal directions or points of the compass. It is the opposite direction from east and is the direction in which the Sun sets on the Earth. Etymology The word "west" is a Germanic word passed into some ...

and Stephensport

group A group is a number of persons or things that are located, gathered, or classed together. Groups of people * Cultural group, a group whose members share the same cultural identity * Ethnic group, a group whose members share the same ethnic ide ...

s that compose the Crawford Upland are

Mississippian Mississippian may refer to: * Mississippian (geology), a subperiod of the Carboniferous period in the geologic timescale, roughly 360 to 325 million years ago *Mississippian culture, a culture of Native American mound-builders from 900 to 1500 AD ...

in age.Lakey, B., Krothe, N.C. (1996). Stable isotopic variation of storm discharge from a perennial karst spring, Indiana. ''Water Resources Research'' 32(3), 721-731

Interstate 64 Interstate 64 (I-64) is an east–west Interstate Highway in the Eastern United States. Its western terminus is at Interstate 70 in Missouri, I-70, U.S. Route 40 in Missouri, U.S. Route 40 (US 40), and U.S. Route 61 in Missouri, ...

traverses this section within Perry, Crawford, Harrison, and Floyd Counties.

References

Karst plateaus Landforms of Indiana Geologic formations of Indiana Mississippian United States {{US-geology-stub