NEW MAP SHOWING THE THICKNESS OF OHIO'S ICE-AGE DEPOSITS NOW AVAILABLE COLUMBUS, OH - The varying thickness of Ice-Age deposits, including clay, silt, sand, gravel, cobbles and boulders, can now be seen in a map available from the Ohio Department of Natural Resources (ODNR) Division of Geological Survey. The new map will be useful and informative to geologists, miners, engineers, consultants, land-use planners, ground-water specialists, environmental professionals, and educators as well as to those interested in the state's natural history. "Ice-Age glaciers advancing across western and northern Ohio smoothed the existing land surface and buried nearly three-quarters of the state under an array of glacial materials known as drift," according to Thomas Berg, state geologist and chief of the Division of Geological Survey. "The new map shows that these deposits are generally less than 50 feet thick, but can reach more than several hundred feet. The ice itself was probably close to a mile thick in places." While the hills of southeastern Ohio were untouched by the glaciers they did not remain unaffected. Meltwaters flowing from the glaciers carried sediment that left thick layers of silt, sand, and gravel in many southeastern Ohio streams. Thick deposits of clay and silt also accumulated in many southeastern Ohio stream valleys that were temporarily dammed and occupied by Ice-Age lakes. Perhaps the most striking features on the new map are the unusually thick drift areas along the former Teays River and its many tributaries. The Teays River was a major north-flowing river in southern and western Ohio prior to and throughout the time of the earliest great glaciers. Now-buried, the Teays River Valley is clearly visible on the map as an area with thick deposits, running between Scioto and Mercer counties. In western Champaign County, glacial deposits along the former river valley are up to 720 feet thick. The full-color map, entitled Shaded drift-thickness map of Ohio, is available in several formats. A wall-size version may be ordered for $15, plus $6.02 for shipping and handling (add $1.50 for mailing tube if map is to be sent rolled). A smaller version can be viewed online at ohiodnr.com. A CD-ROM version in Geographic Information System format may be ordered for $25, plus $8.18 for shipping and handling. Orders can be placed by calling 614-265-6576, or by writing the ODNR Division of Geological Survey, 4383 Fountain Square Drive, Columbus, OH 43224-1362.
Source: ODNR
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