“which determined that sedimentary rock is more conductive than igneous rock”
OK, This has me intrigued... Wonder why? We know igneous has more metals, so what would make sedimentary more conductive? Silica? This needs further investigation. Could explain why Vortexes are found in places with sedimentary. But why?
Oym. Maybe sedimentary contains more water and the water contains mineral salts that allows current flow through fractured areas?? Just a guess.
Wouldn’t sedimentary rock be pervious to water while igneous rock is impervious? So there would be water content in sedimentary rock that would increase conductivity?
But why?>>>>>>>>>>>>>>
We do not know.
We know little about geo conductivity, and even less about the array of energy being conducted, electricticty being only one of several, such as gravity, magnetism, heat, tectonic etc.
I think the key is silica in the form of quartz crystals.