VOCABULARY Nº17

Mineral: a naturally occurring solid in earth's crust with a definite structure and composition.








Igneous rock: a rock that forms when hot, liquid rock material cools and hardens into a solid.








Sedimentary rock: a rock that forms from pieces of other rocks that are squeezed or cemented together.








Metamorphic rock: a rock that forms from another kind of rock that is changed by heat or pressure or by a chemical reaction.








Rock cycle: rocks continually changing from one kind into another in a never-ending process.

VOCABULARY Nº16

Mass wasting: the downhill movement of Earth material caused by gravity.








Deposition: the dropping off of sediment.








Glacier: a huge sheet of ice and snow that moves slowly over the land.








Till: a jumble of many size of sediment deposited by a glacier.








Moraine: a deposit of many size of sediment in front of or along the sides of a glacier.