Forces of Change

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Making a Soil Monolith

A monolith, or vertical slice from topsoil down to subsoil, preserves a soil’s colors and layered horizons in position. Scientists make monoliths of the important soils in their region and use them in teaching.

Step 1
Step 1
In the field, scientists dig a pit about 6 feet deep, keeping one face a flat vertical plane.
Donald Hurlbert, Smithsonian Institution
Step 2
Step 2
Then, they press a mounting board with a bed of nails into the pit face and dig in about 6 inches around the board’s edges.
Donald Hurlbert, Smithsonian Institution
Step 3
Step 3
As they pull the board back, they use strips of cloth to secure the soil to the board.
Donald Hurlbert, Smithsonian Institution
Step 4
Step 4
Back at the lab, the soil is “picked” away to leave about 1 or 2 inches of soil with a natural surface, and then coated with glue or acrylic floor wax to “fix” it to the board.
Donald Hurlbert, Smithsonian Institution