True Detective Season 2 Episode 7: Black Maps and Motel Rooms. Written by Nic Pizzolatto (airs Sunday, August 2nd) Ray (Colin Farrell), Ani (Rachel McAdams) and Paul (Taylor Kitsch) take precautionary measures to elude detection and untangle a dark mystery. Frank (Vince Vaughn) deals with the fallout of his betrayal.
The permeability of the rock samples is likely to be â permeable-sandstone, chalk; impermeable â clay, slate, marble, granite. This may vary according to the samples, e.g. some sandstones may have a mixture of grain sizes and may have poor permeability.
Believe it or not, some porous rocks are considered impermeable. No rock is completely impermeable, but some porous rocks like shale and pumice are mostly impermeable, because â¦ the pores are not interconnected, thus not allowing fluids or gases to pass through them.This is why shale makes a good cap-rock, and pumice floats instead of sinking.o rock is completely impermeable, but some porous rocks like shale and pumice are mostly impermeable, because â¦ the pores are not interconnected, thus not allowing fluids or gases to pass through them. This is why shale makes a good cap-rock, and pumice floats instead of sinking.