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GEOPHYSICAL STUDIES SITE B. GEOPHYSICAL STUDIES PROGRESS OSPER PROJECT SITE B. BRUCE SMITH ROBERT BISDORF RAY HUTTON MARK TABACHECK ROBERT HORTON. GEOPHYSICAL METHODS USED. DC RESISTIVITY SOUNDING obtain variation in electrical resistivity as a function
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GEOPHYSICAL STUDIES SITE B GEOPHYSICAL STUDIES PROGRESS OSPER PROJECT SITE B BRUCE SMITH ROBERT BISDORF RAY HUTTON MARK TABACHECK ROBERT HORTON
GEOPHYSICAL METHODS USED • DC RESISTIVITY SOUNDING • obtain variation in electrical resistivity as a function • of depth (to about 40 meters) • ELECTROMAGNETIC PROFILING (EM31) • obtain variation in electrical conductivity as a function • of position (mapping lateral variations) 3 to 6 meters • TOTAL FIELD MAGNETICS (not discussed) geologic mapping detect magnetic metallic objects (oil field pipes etc.) • ELECTROMAGNETIC PROFILE (EM34…not discussed) • depth to 40m but very noisy due to metallic pipes
ELECTRICAL CROSS SECTION SITE B RESISTIVITY (ohm meters) CONDUCTIVITY (millisiemens) ρ = 1000/σ(ms) σ(ms) = 1000/ρ 100 ohm meters = 10 ms
WEATHERED BEDROCK RESISTIVITY SOUNDING SITE B CONDUCTIVITY 1000 100 10
EM31 CONDUCTIVITY SURVEY Vertical dipoles depth ~4.5m Horizontal dipoles depth ~2.25m