Earth’s outermost layer is separated into a dozen or more large and small slabs, called

Earlier in your passage this question was provided for, you should have been able to find the fallowing text, "Earth’s outermost layer is fragmented into a dozen or more large and small solid slabs, called the lithospheric or tectonic plates."

Tectonic Plates

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.

the answer is minerals.