A layer of red clay had been placed atop the natural floor level.

It is typically found at 750mm down below a layer of yellow clay.

This allows such an even distribution on the different layers of clay.

This is covered over with a layer of clay and structure erected.

Another layer of clay is applied to form a "false bell".

You know, this city is built on some rich layers of pure clay.

Along this southern edge of both there's a layer of clay.

Covering it with a layer of clay or asphalt may be sufficient.

The distressed look is achieved with a layer of sand and clay.

Six inches below the surface she had encountered a dense layer of clay.