The Rock Cycle Learning Objectives To understand how

The Rock Cycle Learning Objectives To understand how different rock types are formed. Learning Outcomes To be able to describe the formation, providing examples or each of the three types of rock. ALL: Describe the formation of each rock type (D/C). Most: Provide named examples of each type of rock (B) Some: Explain how each rock type can be transformed during the rock cycle (A/A*)

START UP TASK • Using Pg. 120 -121 in your text, scan the information and take notes on the three types of rocks that are referenced in this section: – Igneous – Sedimentary – Metamorphic

Rocks We have been using rocks for thousands of years for many different purposes Rocks can have different properties from each other and this gives them different uses

Uses of Rocks How many different uses for rocks can you think of? • • Fossil Fuels Building material for houses, roads, bridges and cities Making cement and concrete The salt in our food is a mineral and pumice stones are used in toothpaste Decoration – from stone statues to gemstones in jewelry Most metals are found in the form of ores Making glass Sandpaper

Types of Rock There are three main types of rock These types share similar properties and are formed in the same way

The Rock Cycle Rocks get broken down by weathering to form sediments to make sedimentary rocks Rocks are melted to form magma and cool to make igneous rocks Rocks are transformed under extreme heat and pressure to make Metamorphic rocks And all these processes are going on constantly at the same time!

The Rock Cycle All of these processes take place at the same time Rocks are slowly over time being turned into different types of rocks over and over again This is called the rock cycle

The Rock Cycle ALL: Describe the formation of each rock type (D/C). Most: Provide named examples of each type of rock (B) Some: Explain how each rock type can be transformed during the rock cycle (A/A*)

The Rock Cycle Beginning of turn Process End of Turn Sediment Compaction and cementation Sedimentary rock Weathering and erosion Sediment ALL: Describe the formation of each rock type (D/C). Most: Provide named examples of each type of rock (B) Some: Explain how each rock type can be transformed during the rock cycle (A/A*)

The Rock Cycle ALL: Describe the formation of each rock type (D/C). Most: Provide named examples of each type of rock (B) Some: Explain how each rock type can be transformed during the rock cycle (A/A*)

Sedimentary Rocks – Properties Sedimentary rocks tend to be crumbly and porous They are made of layers stuck together by mineral crystals They can contain fossils within their layers Sedimentary rocks are the only ones that are porous (allow water to pass through them)

Sedimentary Rocks – How are they made? Sedimentary rocks are made from sediment grains which come from eroded rocks Sediment grains are transported by water, wind or ice They form layers called ‘strata’ Pressure and mineral reactions harden the sediment in to sedimentary rock

Igneous Rocks – Properties Igneous Rocks tend to be very hard They contain crystals and the size of the crystals depends on how slowly the rock cooled when it was formed The quicker the rock cools when it forms the smaller the crystals will be

Igneous Rocks– How are they made? Igneous rocks are formed from magma (molten rock) cooling and becoming solid They can be made below the surface as ‘intrusive rocks’ or above the surface as ‘extrusive rocks’ The magma that makes igneous rocks comes from other rocks that have been melted

Metamorphic Rocks – Properties Metamorphic rocks are usually hard They may contain tiny crystals or layers or distorted fossils They are the hardest to identify Metamorphic comes from the word ‘metamorphism’ which means ‘to change’

Metamorphic Rocks– How are they made? Metamorphic rocks were once either igneous or sedimentary rocks Igneous and sedimentary rocks that are beneath the earths surface can be subject to intense heat and pressure This heat and pressure can change them in to metamorphic rocks

The Rock Cycle

The Rock Cycle 1. Igneous rocks are formed from solidified ____ or lava. If the rate of cooling is slower, the crystals are ____. 2. Metamorphic rocks are formed when rocks are at a high temperature and high ____. 3. Sedimentary rocks form from the hard parts of marine animals or ______ fragments of broken rock. bigger chalk crystalline eroded limestone magma marble pressure sedimentary

The Rock Cycle 1. Igneous rocks are formed from solidified magma or lava. If the rate of cooling is slower, the crystals are bigger. 2. Metamorphic rocks are formed when rocks are at a high temperature and high pressure. 3. Sedimentary rocks form from the hard parts of marine animals or eroded fragments of broken rock.

The Rock Cycle 1. Describe how an igneous rock may become a sedimentary rock, which in turn may become a metamorphic rock. Explain what must happen for the metamorphic rock to become an igneous rock. 2. Name one example for each of the following rock types: a) Igneous rock b) Metamorphic rock c) Sedimentary rock ALL: Describe the formation of each rock type (D/C). Most: Provide named examples of each type of rock (B) Some: Explain how each rock type can be transformed during the rock cycle (A/A*)

Which rock am I? Sedimentary Rock • I am formed from layers of sediment laid down in lakes or seas over millions of years. • I tend to be crumbly and porous. • My layers are stuck together with salt crystals (minerals) • Fossils (remains of plants and animals) can form in my sediments • Examples of me are limestone, chalk and sandstone

Which rock am I? Igneous Rock • I am formed from cooled molten magma which is pushed up to the surface of the crust – and often out through volcanoes. • I am called extrusive if I cool above ground and intrusive if I cool below the ground. • I am very hard and have crystals. The slower I cool the larger my crystals. • Examples of me are granite and basalt.

Which rock am I? Metamorphic Rock • I am formed from existing rocks that have been changed by great heat and pressure over long periods of time. • I am usually hard. • I may have really tiny crystals, I may have some layers and I may have some distorted fossils. • Examples of me are marble, slate and schist.