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Integration Of A Seismic Reflection Survey With Traditional Geological Techniques To Site Monitoring Wells In An Unexploded Ordnance Area
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 13th EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems, Feb 2000, cp-200-00073
Abstract
The complex geological setting of the open burning/ open detonation (OB/OD) area of a former<br>demilitarization facility made conceptual hydrogeologic model development problematic. The<br>OB/OD area is located on the flank of a regional uplift where geologic strata transition from<br>nearly flat lying to dips of nearly 50 degrees. OB/OD operations as well as cutting and deposition<br>by an arroyo located through the center of the area have obscured the surface geology. Explosive<br>constituents have been detected in both the soil and ground water. A seismic reflection survey<br>was performed in the OB/OD area to better define the subsurface geological relationships, and<br>structural features within the area that could be influencing ground water flow. Since the<br>underlying geology strongly influences ground water occurrence and flow, a depth of<br>investigation exceeding 500 feet was necessary to achieve the project objectives. The seismic<br>source for this survey was the iVi Minibuggy vibrator, which is capable of maneuvering in the<br>steep and rugged terrain encountered at this site. One hundred twenty receiver channels were<br>recorded for this survey. To correlate the seismic reflectors to geologic horizons, two borings<br>were installed on one of the seismic lines. Coring and downhole logging were performed to<br>better characterize the geology at those points. Following interpretation of the seismic data, the<br>results were incorporated with traditional sources of geological data such as surface geologic<br>mapping and boring logs. This integrated approach provided an understanding of the site<br>hydrogeology to select monitoring well locations.