Magnetic And Gpr Surveys Of A Former Munitions Foundry Site At The Denver Federal Center

We made magnetometer and ground penetrating radar (GPR) surveys over part of<br>the foundation of a World War II-era foundry located on the Denver Federal Center. The<br>site-contains a number of highly magnetic source bodies, concrete foundation walls, and<br>underground openings, buried under a clay cap. The cap is several feet thick and has a<br>conductivity of about 35 mS/m, making the features underneath it a poor target for<br>conventional GPR. Indeed, the raw data look unlike typical GPR data, but rather show<br>reverberation (?) bands under sidewalks and other shallow buried sources. Using a<br>newly-written computer package, we made plan maps of the GPR response at different<br>time slices. The sliced GPR data did not outline buried foundry foundations, as we had<br>hoped it might. The resulting plan maps of the sliced data show sidewalks and other<br>blobby features, some of which correspond to magnetometer highs.