Some Characteristics of Calcareous Parent Materials

The soils of Ohio may be roughly divided into two main groups, based on the character of the parent materials from which these soils have been derived. The soils of approximately all of the western half of the state have been derived from limestone materials, of either glacial or residual origin, while the soils of the eastern half of the State have been derived from glacial or residual sandstone and shale materials. In other words all but the southeastern one-third of the State has been glaciated. (See Figure 1). The parent materials of the glacial limestone_.group of soils may contain as much_as_JlO percent of calcium carbonate, while the parent materials of the sandstone and shale group of soils seT3onT'c^onTain"nidre than 10 percent~of~calciumLcarbonate, ttSe~mosT pSrT~6"f 'which carbonates are native, with the remainder, accumulated. Thus it is possible to recognize a high-lime and a lowlime group of soils in Ohio. During the past two years, several of the characteristic soil profiles within these two groups of soils were carefully sampled, and a study begun concerned with the base-exchange properties of these profiles in relation to