Indiana Geology and Landscapes - Assignment Example

The ice sheets carried with them sediments, which were a mixture of sand, silt, clay, and stones. When warmer weather finally arrived this mixed silt was left behind as the ice retreated north. arrived the advanced into Indiana and as outwash sand and gravel when the ice melted. The more uneven original bedrock was filled in with this accumulated debris finally producing a gently rolling, somewhat monotonous according to some, landscape. There are hills and areas of higher land, as are shown in the relief map below but this is simply because these parts of the sedimentary rocks, which include limestone, dolomite, shale, sandstone, and siltstone, although they tip to the south west, were always higher in elevation than the intrusive ice sheets.

This is especially so in the northeast of the state, although the highest point is actually in the south in Wayne County, near to the state’s eastern border. The rock there is the oldest in date, being from more than 440 million years ago. according to Indiana University, Department of Earth Sciences ( undated). The same researchers state that the youngest rocks, mostly sandstone with some shale, coal, and limestone, referred to as the McLeansboro Group. This difference in the bedrock explains in part differences in the visible and invisible landscape.

The dissolving of rocks such as limestone leads to karst landscapes with sinkholes and caves as in the Mitchell Plateau in Southern Indiana, as described by The Nature Conservancy, 2012. Stream rise and also disappear among a rolling landscape. The same site describes the Muscatatuck area with similar results from the dissolving of the bedrock, but in this case, the rocks concerned date from the Silurian and Devonian ages. ( See figure 4 ).