Gravity As A Tool To Delineate Buried Valleys

The gravity method with specific emphasis on its use in buried valley<br>studies is reviewed. The technique has been successfully applied in a<br>number of areas. Case studies are presented to illustrate results in two<br>parts of the United States. The Hanford Military Reservation near<br>Richland, Washington, has folded basalt flows and Pleistocene sediments.<br>A residual gravity map, produced by removing a third-order trend surface<br>from the data, allowed interpretation of a buried valley system which is<br>important in controlling groundwater flow. Subsequent studies have<br>supported the conclusions drawn from the gravity data. In southwestern<br>Ohio a number of gravity studies have been used to refine maps of the<br>preglacial drainage system. These gravity maps have located errors in<br>bedrock maps which were based on water well data. Detailed gravity<br>profiles have helped understand the configuration and nature of sediments<br>filling the valleys.