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.