02/04/2026
Marl can be found right here in Champaign County at Cedar Bog Nature Preserve! Thanks to Ohio Geological Survey for highlighting our county's unique geology ๐ชจ๐ง
Geo Term of the Month: marl
๐๐ข๐ณ๐ญ is a deposit rich in carbonate minerals, clay, and silt. In Ohio, marl originates from limestone bedrock and gravel that has been partially dissolved, usually by water flowing through an area.
At Cedar Bog Nature Preserve in Champaign County, marl can be found in the ground below several open areas. The dominant plants in these open areas are sedges (still brown in this early-spring photo), grass-like plants that enjoy wet areas. The substrate below the sedges is a combination of muck and marl: a mixture of decaying plants, silt, clay, and fragments of limestone and gravel.
In other areas of the state, such as along the southern shores of Lake Erie, marl was utilized in construction. Depending on the composition of the muck and marl, it can be dried and hardened into a rock-like substance called ๐ฎ๐ข๐ณ๐ญ๐ด๐ต๐ฐ๐ฏ๐ฆ. When still wet, it can be shaped into bricks and used in construction. Several areas along Lake Erie contain homes with marlstone walls. Marl can also be used in the manufacture of cement. However, the most widespread uses of marl historically was in agriculture as a way to lessen the acidity of soils and provide additional nutrients for plants.
