| Autor: |
Bruce D. Smith, Robert R. McDougal, Douglas B. Yager, Maryla Deszcz-Pan, Anne E. McCafferty |
| Rok vydání: |
2004 |
| Předmět: |
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| Zdroj: |
17th EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems. |
| Popis: |
A helicopter electromagnetic and magnetic (HEM) survey has been done as part of an abandoned mine land study. An important aspect of this study is to estimate ground water flow paths in the surface and subsurface (bedrock). The apparent conductivity and total field magnetic maps from the HEM survey are used to identify geologic features that can influence ground water flow. The most easily understood studied ground water flow paths are near surface streams and flow through alluvial or colluvial deposits. The HEM data indicates parts of the upper Animas River where bedrock ground water flow may be important. Interestingly the other two major drainages (Cement and Mineral Creek) are not associated with geophysical responses that indicate deep structures. High apparent conductivities near one mine waste pile suggest near surface flow paths and a source for high dissolved solids where high sulfide mill tailings have been removed after the HEM survey. The youngest dacite-rhyolite intrusives show different types of magnetic and electrical properties that may have implications for the occurrence of acid generating lithologies. Apparent conductivity maps suggest a northwest trending structural zone along Cement creek that may control ground water flow. Total field magnetic data suggest northwest trending structures that cross the Silverton Caldera ring fracture system. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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