They were the barrier, hard and rocky and almost impermeable.

The nail is often considered an impermeable barrier, but this is not true.

He took a slow deep breath and concentrated, forming an impermeable barrier of hard air around each lord.

According to the suit, however, the city failed to place an impermeable barrier between the remains and the rest of the landfill.

Eventually the area will be covered with an impermeable barrier, soil, and finally grass.

Gas and oil are lighter than water, so they will form a bubble at the high end of the "trap" formed by the impermeable barriers.

Jamison shows that we are really limited in dealing with suicide only insofar as "the privacy of the mind is an impermeable barrier."

She had learned, with what suffering he could never guess, to keep her emotions deeply guarded, hidden behind an impermeable barrier.

Each formation is divided into two different reservoir layers, separated by impermeable barriers.

Oil and gas only collect in rocks that have an impermeable barrier above the rock.