WHAT IS THE EARTH MADE OF BENEATH THE GROUND SURFACE?
The earth is made of a large number of different rocks and minerals (limestone, sandstone, shale, coal, iron, granite, and many others). These materials are divided into three zones: core, mantle, and crust ([fig. 2]).
Figure 1—Physiographic provinces of Illinois.
DRIFTLESS AREA WISCONSINAN MORAINES ILLINOIAN TILL PLAIN MISSISSIPPI RIVER WABASH RIVER SHAWNEE HILLS OHIO RIVER
Figure 2—The earth with a segment removed to show supposed internal zones.
Crust (6-30 miles) Mantle (1800 miles) Outer core (1400 miles) Inner core (750 miles)