Year 8 Geology PDF

Year 8 Geology Name: ________________________  ® keep it simple science “Mind-Map” Outline of Topic This topic is an introduction to Earth Science. Earth Science includes studies of rocks and minerals, earthquakes and volcano...

Year 8 Geology Name: ________________________  ® keep it simple science “Mind-Map” Outline of Topic This topic is an introduction to Earth Science. Earth Science includes studies of rocks and minerals, earthquakes and volcanoes, the weather and the oceans. Earth Science looks at the structure of the Earth itself, and how landforms, and even oceans and continents, come and go over time. The 4 “spheres” Internal of the Earth Structure Structure of the Earth GEOLOGY The Lithosphere Minerals Soils & Landscapes Weathering Igneous, then Sedimentary, Erosion Metamorphic Rocks  ® keep it simple science The Structure of the Earth You already know that the Earth is a planet which orbits our star, the Sun. The Earth is a ball of rock, largely covered by water, and surrounded by a layer of air. Now it is time to learn some more detail. Inside the Solid Earth Ignoring the oceans and the air for a while, we begin with the solid Earth. Scientists have always been interested Crust in earthquakes. By learning about The crust is a very earthquakes it was hoped that we might thin layer Mantle learn to predict them, and so avoid some of low- The mantle is a of the deaths and destruction that they density very thick layer rock. of dense rock. cause. About 100 years ago, the study of earthquakes (called “Seismology”) became advanced enough that scientists began studying the way that earthquake shockwaves travel through the Earth. From this, it became clear that the solid Earth is not totally solid, and has a layer Outer Core structure, as shown. The outer core Inner Core is hot liquid. In the centre is a large ball It is largely a of solid iron & nickel. It is mixture of the The Lithosphere very hot, but huge pressures metals iron & cause it to be solid. But wait, the story gets more complicated! nickel. Attached to the bottom of the crust is a Below the lithosphere is a “slippery layer of mantle rock which has “welded” layer” of the mantle. itself to the crust rocks above. We now know that the Crust & lithosphere under a This 2-part layer is called the lithosphere continent is much thicker “floats” on the than under the oceans. lithosphere. main body of the Lithosphere Crust rocks Ocean mantle, and is Mantle rock broken up into large The thickness of the stuck to the base of the crust lithosphere varies. chunks of Under the oceans, it Main body of the mantle lithosphere, called can be about 5 km tectonic plates. thick and is mostly crust rocks with very little mantle rock attached. Under The plates slowly move around, sliding the continents the lithosphere is over across the “slippery layer” of mantle rock. 100km thick. In later topics you will learn about the Compared to the 6,400 km diameter of tectonic plates and how they slowly move the Earth the lithosphere layer is an around and change the continents, oceans extremely thin shell on the outside. and mountain ranges of the Earth. Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 3 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science The Four “Spheres” of Planet Earth The surface layers of rocks, water and air are home to ourselves and all the other living things we share this planet with. We can think of our “home” as having 4 “spheres”, or parts. The Atmosphere (“atmos” = vapour) The Hydrosphere The atmosphere is the layer of air which (“hydro” = water) surrounds the Earth. The hydrosphere refers to the water It is the layers on the surface of the Earth. atmosphere in which all our As well as the oceans, the weather occurs. hydrosphere includes the polar ice- caps, all the lakes and rivers, and We need to even the underground water. breathe the oxygen gas of the air. Other gases are vital to protect us from dangerous radiation from the Sun. The Lithosphere (“lithos” = rock) The lithosphere was described includes lower atmosphere, hydrosphere ATMOSPHERE previously. It is the thin, outer “skin” and the top part of the lithosphere. has several layers of the solid Earth. BIOSPHERE The lithosphere is made up of the crust layer (low-density rocks) with a layer of the upper mantle attached. Water Cycle This 2-part “skin” is separated from the main body of mantle rock by a “slippery layer” on which the Crust rocks HYDROSPHERE lithosphere floats. LITHOSPHERE r” On the top of the lithosphere is a ry Laye Upper Mantle “Slippe thin layer of soil which we depend rock on for growing our food. The Biosphere will be studied in a The Biosphere (“Bios” = life) later topic The biosphere refers to those parts of the Earth where living things are found. The biosphere overlaps the other “spheres” because living things fly and drift in the atmosphere, swim in the hydrosphere and burrow into the top of the lithosphere. Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 4 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science Worksheet 1 - Earth’s Structure Label the diagram and answer the questions a)............................ e) What study led scientists to an understanding of the internal layers of the Earth? b)............................ f) Which layer is liquid? g) What is the part in the middle made from? h) What is “lithosphere”? Which parts of the Earth are combined c)............................ to make it? d)............................ Worksheet 2 - The “Spheres” of the Earth Fill in the blank spaces. The layer of gases around the Earth is The Lithosphere is a solid 2-part called the a....................................... All layer comprising the c.............................. our w............................ occurs here. and the upper part of the m....................... We rely on the air for o........................ to The lithosphere “floats” on the rock breathe, and to shield us from underneath. It is broken up into a dangerous UV r................................ from number of pieces called “t....................... the Sun. p...................” which can move around. The watery parts of the Earth are called The parts of the Earth where living the h................................. This includes things are found is called the the oceans, and also all the l.................. b........................................ This overlaps and r...................... and underground the other 3 “spheres”, because living water. It also includes the ice in glaciers things are found in all three. and the polar i............. c.................. Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 5 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science The Lithosphere (“lithos” = rock) The solid, rocky outside layer of the Earth is a very thin “skin” compared to the size of the Earth itself. To study the lithosphere, the first step is to learn what it is made from. Rocks are Made from Minerals What is a rock? Most rocks are mixtures of a variety of crystalline chemicals called “minerals”. Each mineral forms crystals of a particular shape, colour and “hardness”. Quartz (or Silica) Calcite The most common mineral on Earth is a Another common mineral is calcite. glass-like substance called quartz. Rocks containing calcite can be easily (It’s not surprising that it’s “glass-like”... identified by placing a drop or two of quartz is the main ingredient for making glass!) acid on them. (A drop of vinegar will do) Many small If calcite is present, the acid will “fizz” fragments of with little bubbles. quartz is what Acid reacts we call sand. chemically with calcite If you hold a to make CO2 rock in sun- gas. That’s light and it what makes “sparkles”, the bubbles. that’s probably because it has small crystals of quartz in it. The rock in limestone caves is mainly calcite. Silicate Minerals The “silicates” are a large family of minerals which are all related to quartz. (Quartz is also known as “silica”) 95% of rocks contain silicates. Each particular silicate mineral is quartz with various chemical elements embedded in its crystal structure. This changes its colour, hardness and crystal shape. The elements embedded in silicates are (most commonly) aluminium, calcium, magnesium, iron and potassium. Some Silicate Minerals Orthoclase Feldspar Olivine Talc Mica Most silicates occur mixed together in common rocks. When they occur in pure crystals they are “gems”, and “semi-p precious stones” Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 6 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science The Rocks of the Lithosphere Rocks can be mixtures of many different minerals combined in any proportions. This means that thousands of different kinds of rock are possible. However, all rocks can be classified into just 3 groups, according to how the rock was formed. Igneous Rocks Igneous rocks are formed from molten minerals that have cooled and solidified. These rocks are associated with volcanic activity. Magma & Lava In many parts of the world, heat and movements in the lithosphere cause the rocks to melt deep below the surface. This molten material is called “magma”. Sometimes it can force its way to the surface and a volcanic eruption occurs. The molten rock that erupts at the surface is Typical cone- called “lava”. shaped volcano in New Zealand Inside a Volcano As the magma or lava cools down, the molten minerals solidify and form solid crystals. This forms igneous rocks. Surface Layers of lava flow Magma cools slowly, deep underground. This lava rock and ash allows the mineral crystals to grow larger and be clearly visible in the rock. Lava cools quickly at the surface, and the crystals are too small to see. The colours vary, too. Igneous rocks with large amounts of quartz are pale in colour. If there is Magma chamber less quartz and more silicate minerals, the colour may be many km is usually darker. underground. Some Common Igneous Rocks Granite Basalt Pumice Granite forms from slow- This is a rock that floats! cooling magma. This is basalt from a recent lava flow. Pumice is like the “froth” on You can see the separate You can still see the flow patterns from lava from volcanic gases mineral crystals, including when it was liquid. Basalt is dark- forming bubbles. a lot of quartz. coloured with microscopic crystals. Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 7 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science The Rocks of the Lithosphere Rocks can be mixtures of many different minerals combined in any proportions. This means that thousands of different kinds of rock are possible. However, all rocks can be classified into just 3 groups, according to how the rock was formed. Sedimentary Rocks Sediments A Mountain of Limestone Limestone is mostly calcite mineral Rocks are worn down and carried away by water, wind and ice. Erosion of rocks produces gravel and sand and silt, or mud. Eventually, these eroded fragments settle to the bottom of a lake or ocean. These are called sediments. As more and more sediments This entire mountain range is made of accumulate on top, the layers are sedimentary rocks which have been uplifted from compressed by huge forces. Any water the ancient seafloor by earth movements. is squeezed out. The grains become You can clearly see the sedimentary layers. cemented together and the whole mass During erosion, the pebbles, mud, sand, becomes a hard rock. (Although it’s etc. are often sorted out and separated usually not as hard as igneous rock) from each other. Sediments are often made of particles all the same size. Fossils Some sedimentary rocks contain the remains and traces of ancient Common living things that were buried Sedimentary Rocks in the sediments. Shale This rock forms from layers of silt, clay or mud. Colours vary, but it is fine-grained. You can see the This fish lived 150 million years ago. sedimentary layers Its body was trapped in silt which later in this sample. became shale rock. Conglomerate You can see that Sandstone this rock is made Forms from from gravel sand particles cemented with compressed and a dark mud. cemented together. This piece has been cut to make a decorative wall. Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 8 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science The Rocks of the Lithosphere Rocks can be mixtures of many different minerals combined in any proportions. This means that thousands of different kinds of rock are possible. However, all rocks can be classified into just 3 groups, according to how the rock was formed. Metamorphic Rocks These are rocks that are formed when a previous igneous or sedimentary rock is changed by extreme heat and/or pressure within the lithosphere. Heat & Pressure Causes Changes The extreme heat near a chamber of molten magma can cause changes to Flat slabs of surrounding sedimentary rocks. Slate formed from compressed For example, the shale rock sand particles in sedimentary sandstone can partly melt so they all fuse together to The massive movements of the form a mass of lithosphere that slowly push the glassy quartzite continents around and lift up entire Quartzite rock. mountain ranges generate enormous, relentless forces. Perhaps the best known metamorphic rock is marble. It is formed from These forces can squeeze rock so much limestone, a sedimentary rock that its structure changes. Slate is a containing a lot of calcite mineral. hard metamorphic rock formed from shale that has been pressurised. Under great heat and pressure, the calcite is re-crystallised and the rock It splits into thin slabs that make it becomes much harder. Beautiful useful for roof and floor tiles. colours and patterns may develop due to small amounts of other minerals in it. A decorative use of marble People have been using marble for statues and decorative structures for thousands of years. Just like the limestone from which it came, marble will “fizz” if a few drops of acid are placed on it. Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 9 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science Worksheet 3 - Rocks & Minerals Fill in the blank spaces. Minerals Sedimentary Rocks Most rocks are mixtures of various Rocks and soil are worn down and m................................, each with its own carried away by water, wind, etc. This is c........................ shape, colour and called e........................... Eventually the hardness. sand, clay or silt is deposited on a lake or sea floor as s................................ The most common mineral on Earth is More and more layers accumulate, q................................ which is hard and c.................................. the layers below, g...................-like. until the sediments become rock. Often, some mineral in the sediments acts like Another common mineral is calcite, c.............................. and helps hold the which is easily identified by placing a rock together. drop of a....................... on a rock sample. If calcite is present, it will Sometimes the body or traces of living f..................... or b............................ things are trapped in the sediments and are preserved as f............................... 95% of rocks contain one or more of the many types of s.............................. Two common sedimentary rocks are minerals. These are based on quartz, shale, made from s.........., c.......... or but have various metals embedded in m....... sediments, and s......................... the c............................ structure. This from sand. changes the colour, crystal shape and h.............................. Metamorphic Rocks These are made when an existing rock is Igneous Rocks changed by h.............................. and/or Igneous rocks form from m....................... p..................................... minerals and are associated with v.................................. activity. The heat from nearby v.......................... activity can change sandstone into Molten rock deep in the Earth is called q........................................ m................................ If it cools deep underground, it will cool s........................ The huge p............................... that and mineral crystals have time to grow. occur when mountain ranges are being A common rock of this type is formed can squeeze shale into a new g............................. in which you can structure called s............................... easily see different m................................ c........................... Rocks containing a lot of calcite, such as l...................................... can be re- If the molten rock erupts at the surface it crystallised by heat and pressure to is called l.......................... This cools become m..................................... This q..............................., so the crystals are beautiful rock has been used for statues very s............................. A common rock for thousands of years. of this type is b.............................. Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 10 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science Weathering of Rocks Most rocks are pretty hard, but they’re not indestructable. Rocks are gradually “broken down” into smaller pieces, and chemically changed into new substances. This breaking-down of rock is called weathering. There are 2 quite different weathering processes that occur. Physical Weathering Chemical Weathering This means the physical breaking of This is when the minerals in a rock are rock into smaller particles, without chemically changed by reaction with changing it chemically. oxygen and natural acid chemicals in the environment. The classic example is when quartz crystals are broken into small fragments The crystal structure of the mineral to form sand grains. It’s still quartz, but the grains are smaller. changes to a new, softer substance, and the rock softens and falls apart. What causes physical weathering? Quartz does not change chemically, (it One of the main causes is temperature only breaks physically into sand grains) change. On a hot day the outside of a but many of the silcate minerals change rock becomes hot and expands slightly. into what we might call “clay”. At night it gets cold and contracts. Rocks containing This cycle of expanding and contracting the mineral calcite cracks the surface and small fragments are especially easy fall off. On a cold night in the to weather. As you mountains, you can often hear the know, calcite reacts clatter of small rock fragments tumbling down the cliffs and gorges. chemically with acids. If water with If it gets some dissolved acid cold seeps through enough calcite rocks, the to freeze rock slowly water dissolves away. This this is how limestone process caves develop. speeds up. Water This boeuintcgrowpeoatfhgerraenditbeyrotecmk pneeraartuArremcidhaalneg, eNsS. W is So, where do the acids come from? seeps into cracks in the rock. When it freezes, Carbon dioxide (CO2) gas from the air it expands and cracks the rock further until pieces break off. dissolves in water to form a (very weak) acid solution. Living things in the soil Another major process of physical produce natural acids, and the rotting of weathering is the tumbling of stones in dead vegetation releases natural acids. a fast-flowing river, or by the waves near the coast. Sand and rocks are tossed In many cases, both physical and and tumbled together so they are first chemical weathering occur together. rounded, and then worn down into Rock becomes fragmented and smaller and smaller pieces. softened, so that it disintegrates. Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 11 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science Erosion After rocks have been weathered, another process becomes possible. Erosion is the transport of rock and soil from one place to another. The main things which cause erosion are flowing water or ice, and the wind. Wind Erosion Erosion by Water In deserts and along beaches, the wind Moving water is a major cause of often moves loose dust and sand. Sand erosion. is often piled up to form “sand dunes”. As rivers flow, they carry tonnes of fine These can slowly “migrate” as sand is sand and “silt” down to the sea. blown up and over the top, and Eventually these solid particles will cascades down the other side. settle to form sediments. They may form sand-bars, or beaches, or simply be buried to become new sedimentary rocks millions of years later. Sand Dunes Erosion by Ice There are no glaciers in Australia, but in many colder climate areas, they are one of the most important agents of erosion. In steep mountain creeks, the fast flowing water can transport pebbles and A glacier is nature’s bulldozer. The slow, boulders. The tumbling stones help cut relentless movement of billions of through the bed-rock and gouge out tonnes of ice gouges out the rock, canyons and valleys. weathering and eroding in one step. The action of waves at the coast is a powerful agent of erosion. Waves “undercut” the rock at sea level. Then the rock above collapses, leaving vertical Rock cliffs. Platform This chunk of ice has broken off a glacier and has floated across a melt-w water lake. Notice the load of At water level, a flat rock platform shows where the broken rock it is carrying. This ice must have been base of the cliff used to be, before erosion. at the base or side of the glacier and gouged the rock from the mountains visible in the background. These sea cliffs are at “The Gap”, When the ice melts, the rock will be deposited, Watsons Bay, Sydney. then washed away again by flowing water. Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 12 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science Soil Formation We rely heavily on soil for growing food crops and grass for grazing animals. Good soil can take thousands of years to develop, and is often less than a metre thick. Soil formation depends on weathering and erosion. A Soil Profile “Topsoil” is usually The diagram shows a cross darker than subsoil section through a soil which because it contains has formed from the bedrock “humus”. underneath. This is rotted plant material which changes Working from the bottom the texture of the soil, upwards, the profile reveals helps hold moisture and the stages in soil formation. fertilizes plant roots. The topsoil is the Fine-grained essential, fertile layer. sand and clay “subsoil” The plants and rotting humus produce acids Rock broken into which seep down smaller pieces. through the subsoil. Quartz forms sand This causes the grains. Chemical chemical weathering. weathering turns silicates into clay. Cracked and broken rock... weathering beginning. Tree roots often grow into cracks Solid bedrock, and break the not yet rock. Tree roots weathered growing through rock. Deposition Soils River Floodplain Many soils are formed by erosion and deposition, rather than weathering of the bedrock. The soil in this photo has been deposited as alluvial sediments during floods. Floodplains are flat and ideal for farming and each flood deposits another silt layer, so the soil stays fertile. Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 13 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science Landscapes Formed by Erosion & Deposition Many landscapes, both ordinary and spectacular, are the result of the weathering then erosion of rock, or the deposition of sediments. Erosion by Rain Wind Erosion The soft This rock formation in Western volcanic Australia is called “Wave Rock”. It ash of has been eroded into this shape this part by wind-blown sand. of Turkey washes away in rain, except where it is “capped” by harder, darker rock. Erosion has produced these strange “fairy chimneys”. Local people Photo by Pat Bride hollow them out to use as homes. River Erosion & Deposition Once they’re down out of the mountains, rivers meander sideways and erode a wider and wider valley. Seasonal flooding deposits sediments to form a flat floodplain. Flood waters cut new channels creating islands, and river meanders get cut-off to form billabongs , or “ox-bow lakes”. Ice Erosion A glacier once filled this valley and gouged out all the rock. Coastal Deposition This sand spit and beaches have The U-shape is typical formed from sand deposited by tides of erosion by ice. rushing in and out of this coastal bay. (Mountain valleys eroded by water are V-shaped) U-s shaped Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 14 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science Worksheet 4 - Weathering then Erosion Answer these Questions in the spaces provided. 1. 4. Explain the difference between physical List 3 things which cause erosion. weathering and chemical weathering by completing these sentences....................................................................................................................................... Physical weathering breaks rock into s.................... p........................, but does................................................................... not change it into a n...... s......................... 5. Complete the sentences to describe Chemical weathering changes rocks the ways that soil can form. and minerals into n...................... c........................... s............................... Soil can form from the underlying bedrock by w................................. of the 2. rock. The rock is p........................... a) Describe 2 things which cause broken into smaller particles, and also physical weathering of rock. c.................................. changed into substances such as clay..................................................................... Good “t...........................” always.................................................................... contains a lot of “h................” which is b) Name a substance which can react to rotted plant material. cause chemical weathering. Some soils are formed by d.......................................................................................... of eroded silt. On a river f..............plain, every flood deposits a new l..................... 3. Explain the difference between 6. Give one example of a landscape weathering and erosion by completing created by: these sentences. a) wave erosion Weathering b........................... rock into at a coastline......................................... smaller pieces, or changes it into b) deposition of sediments n............... s.......................................... on a coastline......................................... c) river erosion and Erosion t.......................... the weathered seasonal flooding.................................. material to a d..................... l...................... 7. What do you think has created the landscapes in these photos? a)................................................ b).................................................... Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 15 www.keepitsimplescience.com.au Site Licence Conditions only River Landforms Use the diagram on the previous page and the word list below to complete the statements that follow. Word List: billabong large overlapping rapids fast hardness flood plain meanders waterfalls meander flood plains winds deposition horseshoe eroded V‐shaped estuary river terraces delta valley floor Headwater Tract Steep‐sided valleys are formed in the mountains by flowing rivers which carry broken down rock fragments. The water flows over rocks of different which are at different rates. This results in the formation of and. As a river through the mountains, the sides of its valley form spurs. Middle Tract As the river leaves the mountains it slows down and widens and starts to. These are shaped like a. Particularly in times of flood, they can be silted up and cut off from the main channel to form a. In the middle tract the river channel only occupies part of the valley floor because of of the transported material as the water slows down. The rest of the valley floor forms a. As the curves of the river continually change, all or part of the older will be carried away. The remains of a number of older form a series of large steps called. Coastal Tract As the river nears the coast, the becomes broader and the river occupies only a small part of the. The speed of the water decreases further, resulting in the of more transported material. On reaching the sea, this may form a fan‐shaped structure called a building up at the river mouth. A tidal inlet formed when a river nears the sea is called an. Page 17 Coastal Landforms Use the diagram above and the word list below to complete the statements that follow. Word List: stack rock platform lagoon caves blowholes beaches waves sand sand spits When pound cliffs, undercutting the bottom of the rock, a flat area called a is often formed out from the base. In the less resistant areas of the cliff, and may be formed. Erosion usually occurs faster at the sides of a headland than at its tip. This may result in the formation of a. grains are carried by waves and currents along the coast. They may be deposited in calm conditions to form and. A is created when a sand spit blocks off a bay. Page 18  Glacial Landforms 1. Before the snow and ice melts 2. After the snow and ice melts  Use the diagrams on the previous page and the word list below to complete the statements that follow. Word List: cirque terminal moraine waterfall U gravity lateral moraine glaciers hanging valleys erosion comb ridges are rivers of ice formed above the snowline in high mountain regions. They flow down the mountain due to the force of and gouge out shaped valleys. The weathered rock left at the end of the glacier as the ice melts is called a. Rock material picked up by the glacier from the sides of its valley forms a. The armchair‐shaped region at the head of a glacier is called a. The razor‐edged areas between valleys are called. When the ice melts, the valleys of tributary glaciers are left suspended above the main valley because the has not been as great. These suspended valleys are called and usually have a at their ends. Page 20  ® keep it simple science Topic Test Geology Student Name............................................. Score = /15 3. (5 marks) Answer all questions Match each description to an item from in the spaces provided. the list. To answer, write the letter (A,B,C, etc) of the list item beside the 1. (6 marks) description. True of False? T or F a) The innermost layer of the Description matches with List Item Earth is liquid....... b)Silicate minerals are similar a) Combination of crust plus to calcite....... upper mantle rocks.............. c) Slow-cooling igneous rocks have the smallest crystals....... b) Most common mineral.............. d) Fossils are found in c) Molten rock, deep igneous rocks....... underground.............. e)Temperature change can cause physical weathering....... d) Metamorphic rock, f) Sand dunes are created by from limestone.............. wind erosion....... e) Causes a lot of chemical weathering............. and............ 2. (4 marks) Briefly explain the difference between: List Items Not all will be used. Some may be used more than once. a) magma and lava. A. lava E. magma B. quartz F. calcite C. oxygen G. lithosphere D. acid H. marble b) weathering and erosion. Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 21 www.keepitsimplescience.com.au Site Licence Conditions only  ® keep it simple science Answer Section Worksheet 1 Worksheet 4 1. a) Crust b) Mantle c) Outer Core d) Inner Core a) smaller pieces b) new substance e) Seismology: study of earthquake waves c) new chemical substances f) Outer core 2. g) iron & nickel metals a) temperature change, h) It is the solid outer layer of the Earth. flowing water tumbling rocks It is made up of the crust rocks with b) acid or oxygen some mantle rock attached. 3. a) breaks b) new substances Worksheet 2 c) transports d) different location a) atmosphere b) weather 4. c) oxygen d) radiation Moving water, wind, ice (glaciers) e) hydrosphere f) lakes & rivers 5. g) ice caps h) crust a) weathering b) physically i) mantle j) tectonic plates c) chemically d) topsoil k) biosphere e) humus f) deposition g) flood h) layer 6. a) sea cliffs b) beach, sand bar Worksheet 3 c) floodplain 7. a) minerals b) crystal c) quartz d) glass- Wind erosion e) acid f) fizz / bubble Wave erosion g) silicate h) crystal i) hardness j) molten k) volcanic l) magma m) slowly n) granite o) mineral crystals p) lava q) quickly r) small s) basalt Topic Test 1. t) erosion u) sediments a) F b) F c) F d) F e) T f) T v) compressing w) cement x) fossils y) silt / clay / mud z) sandstone 2. aa) heat and/or pressure a) Magma is molten rock deep ab) volcanic ac) quartzite underground, while lava is molten rock ad) pressures ae) slate at the surface. af) limestone ag) marble b) Weathering breaks rock down, erosion moves it to a new location. 3. a) G b) B c) E d) H e) C and D Year 8 Topic 8.2 "Geology" Usage & copying is permitted according to the copyright © 2008 keep it simple science Page 22 www.keepitsimplescience.com.au Site Licence Conditions only