What Are Rocks Made of?

Rocks formed from sedimentary rocks due to pressure and high temperature.

• sedimentary rocks

• igneous rocks

• metamorphic rocks

Rocks formed by the deposit of detritus formed in layers by chemical action or by the change of plants and animal corpses in decomposed material.

• metamorphic rocks

• sedimentary rocks

• igneous rocks

Compound of solid materials such as mineral and rocks, organic matter, water, and air.

• soil

• rocks

• roots

Rocks that are product of the crystallization and solidification of magma.

• igneous rocks

• sedimentary rocks

• metamorphic rocks

What's the main cause of depletion?

• intensive farming

• erosion

• chemical pollution

What's the main cause of erosion?

• clearcutting or felling

• burnings

• pesticides

What's the main cause of loss of humus?

• burnings

• erosion

• depletion

What's the main cause of chemical pollution?

• uncontrolled application of pesticides

• overgrazing

• monoculture

pH is a measurement of the acidity or alkalinity of soil that tells us how many H+ ions are present in the substance.

• true

• false

Rocks are the Earth's historical record.

• true

• false