442 EXPLORATION GEOPHYSICS 



TABLE 15 (Continued) 



RESISTIVITIES OF MATERIALS FOUND IN THE OUTER 

 CRUST OF THE EARTH 



Resistivity 

 Minerals and Ores ohm-cm 



Slate 6x10* - 8x10* 



Soil 2x10" - 1x10" 



Unconsolidated and recent formations 

 (marls, clays, sands, alluvial de- 

 posits, etc.) 5x10^-1x10* 



Anhydrite 10' - 10' 



Arsenopyrite 2x10^ 



Bornite 0.5 - 5x10^ 



Calcite >10' 



Chalcocite 0.1 - 6x10^ 



Chalcopyrite 1.5x10"='- 3.5x10^ 



Chalcopyrite-Hematite 5.5 



Chalcopyrite-Sphalerite 1 



Chalcopyrite-Pyrrhotite <0.1 



Chromite 1x10^ - 2x10' 



Coal (Bituminous) 6x10' - 10' 



Coal (Anthracite) 1x10' - 2x10' 



Coal (Lignite) 9x10" - 2x10* 



Cobalt Iron 5x10-" 



Copper 1.5x10-* - 1.5x10-' 



Copper-Iron 0.7 



Covellite <0.1 



Cuprite 3x10* 



Diamond 1x10" 



Galena 3xl0-« - 2x10' 



Galena-Sphalerite 6-10* 



Graphite 8x10"* - 6 



Hematite 5x10* - 10' 



Hematite (specular) 0.4 



Limonite 1x10' - 1x10' 



Magnetite 0.6 - 5x10'' 



Marcasite 1 - 3.5x10" 



Meteoric iron (oxidized) >10^ 



Mica 9x10* - 9x10' 



Molybdenite 0.1 - 5x10' 



Nickel 1x10-' - 1.5x10"' 



Nickel-Cobalt 5x10-" - 6x10"' 



Pyrite 5x10-" - IxlQ-* 



Pyrite-Chalcopyrite <0.1 



Pyrite-Pyrrhotite <0.1 



Pyrolusite-Psilomelane (mixed) 0.5 



Pyrrhotite 5x10-" - 5.0 



Quartz >10' 



Rock Salt 3x10" - >10' 



Serpentine 2x10* - 3x10^ 



Siderite 7x.W 



Sphalerite 1.5x10" - 1.5x10" 



Stibnite >10' 



Sulphur >10' 



Wulframite 1x10" - 1x10' 



