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.
Characteristics of rocks. Some rocks are harder than others. For example, granite is a very hard rock, but chalk is a very soft rock and wears away easily. Some rocks, such as sandstone or chalk, let water soak through them.They are called permeable rocks.haracteristics of rocks. Some rocks are harder than others. For example, granite is a very hard rock, but chalk is a very soft rock and wears away easily. Some rocks, such as sandstone or chalk, let water soak through them. They are called permeable rocks.