3.1 Notes

The rock cycle shows how rocks change

Most Rocks are Made of Minerals

•Just as the pieces of a jigsaw puzzle combine to form the picture, minerals combine to form most rocks.

Most Rocks are Made of Minerals

•Just as letters combine to form words, minerals combine to make rocks.

Most Rocks are Made of Minerals

•A rock is a naturally formed solid that is usually made up of one or more types of minerals.

Most Rocks are Made of Minerals

•The proportion of different elements in a particular kind of rock may change.

Most Rocks are Made of Minerals

•The minerals in a rock can be jumbled together with no crystal structure.

Most Rocks are Made of Minerals

•A few rocks are made up of only one mineral.•Example: Limestone can be made up of pure Calcite.

Most Rocks are Made of Minerals

•A few rocks are made up of no minerals.•Example: Obsidian

Our World is Built of Rocks

•Beneath the surface, Earth is made of solid and molten rock.

Our World is Built of Rocks

•People use rocks for many purposes, including…

Our World is Built of Rocks

•The building of houses and skyscrapers

Our World is Built of Rocks

•Sources of metal like iron and copper.

Our World is Built of Rocks

•The carving of statues and other works of art.

Our World is Built of Rocks

•As a base for pavement for roads and highways

Our World is Built of Rocks

•People study rocks to learn how areas have changed through time.

Rocks Change as They Move Through the Rock Cycle

•Rocks change over thousands to millions of years.•The rock cycle is the set of natural processes that form, change, break down, and re-form rocks.

Rocks Change as they Move Through the Rock Cycle

•Rocks do not move through the rock cycle in a particular order. •The rock cycle has no beginning or ending but goes on continually.

Rock Types

•The 3 types of rock are classified by how they form.

Rock Types

•Igneous rock forms when molten rock cools and becomes solid.

Rock Types

•Igneous rock can form within Earth, or it can form on Earth’s surface.

Rock Types

•Sedimentary rocks is formed when pieces of older rocks, plants, and other loose material get pressed or cemented together.

Rock Types

•Loose material is carried by water or wind and then settles out, forming layers that are pressed down into rock.

Rock Types

•Metamorphic rock forms when heat or pressure causes older rocks to change into new types of rocks.

Rock Types

•The changes in heat and pressure cause the structure of the rock to change and new minerals to form.

Rocks in the Crust

•Igneous, sedimentary, and metamorphic rocks are all found in Earth’s crust.

Rocks in the Crust

•Most of Earth’s crust (95%) consists of igneous rock and metamorphic rock. •Sedimentary rock makes up only 5% of the crust.

Rocks in the Crust

•Sedimentary rocks are the most common type found at the surface because they are formed by processes that occur at the surface.

Review

1.The 3 groups of rock are sedimentary, metamorphic, and

A.LimestoneB.GraniteC.IgneousD.Coal

Review

2. The rock cycle shows how rocks continuallyA.Increase in sizeB.Increase in numberC.Become more complexD.Change over time

Review

3. What kind of rock forms when molten rock cools?A.MetamorphicB.SedimentaryC.IgneousD.Extrusive

Review

4. An existing rock can change into another type of rock when it is subjected to greatA.PressureB.Winds C.FloodingD.Foliation