They rode for a week across the rock and hardpan.

The transition was sharp when they reached the end of the hardpan.

"Lift at once and make for the hardpan outside the city.

He got up and pitched his cigarette out onto the hardpan.

The hardpan was expected to be encountered within a depth of 6 feet.

The depth to hardpan ranged from 1 foot to 6 feet.

When the lakes dry up, they leave a crust or hardpan behind.

Out here there was only the road, the sand, the baked hardpan of the desert.

First the hardpan had been worked for the dust and nuggets it contained.

I'm taking him, my wife, and her mother and heading for the hardpan.

Despite the rain earlier the hardpan was dry just inches beneath the surface.

Dumped them over the side and onto the hardpan.

In half a minute they were crossing the hardpan of the spaceport itself.

There may be a clay soil hardpan beneath the area where mold appears.

Soon there was nothing more than a pair of deep ruts worn through the hardpan.

The term desert comes from the large hardpan (salt flat) that covers the area.

A red clay loam layer above the hardpan was recognized.

Strong trade winds blew away most of the topsoil, leaving behind red hardpan.

The hardpan and mesa terrain was familiar to him.

I nodded, squinting into the red brightness reflected off my hardpan yard.

Part of this soil profile includes an underlying clay or iron hardpan.

Care was taken to maintain vertical profiles every five feet and to keep a clean floor in the trench going down to the hardpan.

Richard cast the pebbles back down the hardpan trail.

Its roots break up hardpan surfaces, while simultaneously holding together the soil to prevent erosion.

His eyes traveled out beyond the hut for a moment, toward the gritty, featureless hardpan.