GEOLOGY UNIT STANDARD
advertisement
GEOLOGY UNIT STANDARD “Demonstrate knowledge of Earth Science” US 18982 (v5), 2 credits UNIT STANDARD Title: Credits: 2 Demonstrate knowledge of Earth science Level: 1 Purpose: People credited with this unit standard are able to: describe the structure of the Earth; describe the formation of rocks; describe the breakdown of rocks; and identify rocks in a local area. Classification: Science > Earth Science Available grade: Achieved Outcomes and evidence requirements Outcome 1 Describe the structure of the Earth. Evidence requirements 1.1 The description outlines features of the Earth’s structure. Range features include – mantle, core, crust, plates (evidence of three features is required). Outcome 2 Describe the formation of rocks. Evidence requirements 2.1 The description outlines the process of rock formation. Range processes include – sedimentary, igneous, metamorphic (evidence of two processes is required). Outcome 3 Describe the breakdown of rocks. Evidence requirements 3.1 The description outlines natural processes that break down rocks. Range natural processes include – rain, wind, ice, temperature changes, mechanical weathering, chemical weathering, biological weathering (evidence of three natural processes is required). Outcome 4 Identify rocks in a local area. Evidence requirements 4.1 Rocks in a local area are identified by name and type. Range types of rock include – sedimentary, igneous, metamorphic (evidence of two named rocks, of any type is required). This unit standard is expiring. Assessment against the standard must take place by the last date for assessment set out below. Status information and last date for assessment for superseded versions Process Version Date Last Date for Assessment Registration 1 26 February 2002 31 December 2012 Review 2 23 August 2005 31 December 2012 Review 3 30 November 2010 31 December 2012 Rollover 4 20 October 2011 31 December 2012 Rollover and Revision 5 20 September 2012 31 December 2016 Rollover 6 22 May 2014 31 December 2016 Consent and Moderation Requirements (CMR) reference 0226 This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do . 1 MY PET ROCK And I shall call him/her _________________________________. Describe how it looks and feels Describe where it was found A diagram of my rock: This is to come back to when you have finished the topic... Tell the story of your pet rock... How did it get into the stream? Where was it before that, and how did it get there? 2 THE STRUCTURE OF THE EARTH This is a great clip. ( http://www.youtube.com/watch?v=QDqskltCixA&safe=active ) -from Nat. Geographic From BBC bitesize: The Earth is made up of four distinct layers: 1. The I__________ C_________ is in the centre and is the hottest part of the Earth. It is s_________ and made up of the metals i_______ and n________ with temperatures of up to 5,500°C. With its immense heat energy, the inner core is like the engine room of the Earth. 2. The O__________ C________ is the layer surrounding the inner core. It is a l__________ layer, also made up of iron and nickel. It is still extremely hot, with temperatures similar to the inner core. 3. The m_________ is the widest section of the Earth. The mantle is made up of semi-molten rock called m__________ ( hint: think Dr Evil ). In the upper parts of the mantle the rock is hard, but lower down the rock is soft and beginning to melt. 4. The c________ is the outer layer of the earth. It is a thin layer between 0-60 km thick. The crust is the s________ rock layer upon which we live. The diagram shows the “cross section” of the earth. 3 The cause of earthquakes and volcanoes: The Earth's crust is broken up into pieces called plates. Heat rising and falling inside the mantle creates convection currents generated by radioactive decay in the core. The c____________ c____________ move the plates. Where convection currents move away from each other plates move a___________. Where c_____________ c_____________ come together plates c_____________. The movement of the plates, and the activity inside the Earth, is called plate tectonics . Plate tectonics cause e_________________ and v________________. The point where two plates meet is called a plate boundary . Earthquakes and volcanoes are most likely to occur either on or near plate boundaries. N____ Z___________ is on the edge of a p_______ b_______________ that is why we have v____________ and e______________. 4 Summary: The Earth consists of four layers . Draw and label. ______________________________ ______________________________ ______________________________ ______________________________ As the m_____________ in the m______________ is heated and cooled it causes a “convection current”, like in a boiling jug. This puts pressure on the crust above. The crust is made up of t_________________ p__________________ which are always moving. E_________________ and v_________________ are most likely to occur at plate boundaries. 5 WEATHERING INFORMATION Weathering breaks down rocks into smaller pieces. Three important classifications of weathering processes exist – physical , chemical and biological weathering. Optional: http://www.kidsgeo.com/geology-for-kids/0066-mechanical-weathering.php Scroll down and ignore the games and tables in between to get further information on the process of weathering. This site will help you complete the worksheet along with the notes below. Physical (mechanical) weathering Happens especially in places where there is little soil and few plants grow, such as in mountain regions and hot deserts. Involves one or more of: ● Temperature - the heating and cooling of rocks causing expansion and contraction. As temperatures heat up, the rocks themselves expand. As the temperatures cool down, rocks contract slightly. That movement can cause rocks to crack and break apart. ● Ice - Water freezes at night and expands. This wedges the rocks apart. Needs supply of moisture; moisture must be able to enter rock or soil; and temperature must move back and forth over freezing point. ● Rushing water in streams and rivers cause rocks to break into smaller pieces from contact with each other. This scraping against each other causes the rocks to become round and smooth. ● Wind abrasion (rubbing or scraping) can also cause physical weathering. Imagine a wind storm blowing across a broad expanse of sandy desert. The wind-sandpaper scours off pieces of grit and sand from rocks. Chemical weathering - the breakdown of rocks by chemicals. Obviously the main chemical is water which carries carbonic acid (carbon dioxide dissolved in water). Rainwater chemically erodes most rock, particularly limestone. Biological weathering includes the effect of animals and plants. This is more than roots digging in and wedging rocks. Biological weathering is the actual molecular breakdown of minerals. There are things called lichens (combinations of fungi and algae) which live on rocks. Lichens slowly eat away at the surface of rocks. EROSION Is the moving of material from one place to another place. Water is responsible for the bulk of erosion on the planet, from: ● ocean waves and currents ● streams , rivers , and floods carry sediment ● glaciers (frozen water) also moves large amounts of weathered rock 6 WEATHERING WORKSHEET 1. Using the resources provided, explain what each word means to weathering. 1 or 2 sentences for each word is fine. Word: Meaning: biological chemical physical ice wind temperature water erosion 2. Give a nearby example of erosion removing sediments 7 THE FORMATION OF SEDIMENTARY ROCKS Have you ever been to the beach and nestled your toes in the sand? Over thousands of years that sand might become part of a sedimentary rock! Sedimentary rock: A rock formed by sediment deposited in layers and stuck together. Sedimentary rocks make up about three-quarters of the rocks at the Earth’s surface. They form at the surface in environments such as beaches, rivers, the ocean, and anywhere that sand, mud, and other types of sediment collect. Sedimentary rocks preserve a record of the environments that existed when they formed (including fossils ). Common examples: Limestone Conglomerate Sandstone Mudstone Coal 8 SEDIMENTARY ROCKS WORKSHEET 1. What are the main processes leading to sedimentary rock formation? 2. Use the following words to write 2 or 3 sentences describing how sedimentary rocks are formed: weathering , sediments, transport , sea , lake , river , depositing , cementing , 3. Fill in this table showing the particle (sand, mud, pebbles, shells, silt) and where it is formed (river, sea, lake) Name of rock Particles Where formed Conglomerate Mudstone Sandstone Limestone Coal 9 THE FORMATION OF METAMORPHIC ROCKS These form from an existing rock that is changed by extreme heat and/or pressure . The pressure and heat responsible for metamorphic rocks come from: ● the internal heat of the earth (near the mantle) ● intruding magma within the crust ● the weight of overlying rock Typically occurs at depths between 10 to 30 km where pressure is 6 times greater and temperature is 800 °C greater than at the surface of the earth! Metamorphic rocks are denser and harder than igneous and sedimentary rocks. Limestone turns into Granite turns into Basalt turns into Marble Gneiss Schist 10 METAMORPHIC ROCKS WORKSHEET 1. Complete the diagram to show how metamorphic rocks are formed. Word list: Gneiss Limestone Granite Marble Uplift Burial Extreme heat/pressure Metamorphism 2. Complete the table: Starting rock type Name Igneous Granite Made into Igneous Schist Sedimentary Marble 11 THE FORMATION OF IGNEOUS ROCKS Igneous rocks are formed of magma, from the Earth’s mantle. VOLCANIC Igneous rocks can form above ground as lava spewing from volcanoes. This cools fast so crystals are small . There may be gas bubbles in it. Examples: Pumice Basalt Obsidian Scoria PLUTONIC But igneous rocks can also form underground . Pockets of magma get stuck in layers of the earth. As they get closer and closer to the surface, the magma slowly cools so large crystals can form. Examples: Granite Diorite Gabbro 12 IGNEOUS ROCKS WORKSHEET 1. What material are all igneous rocks formed from? 2. Complete the table 2 types of igneous: P__________________ V__________________ How they are formed Characteristics Names of examples 3. Indicate on the diagram where Volcanic and Plutonic rocks would form. 4. Explain what would cause the layers shown in the diagram. 13 SOME COMMON ROCKS Rock Type Characteristics (how do you identify it) Limestone Marble Granite Coal Sandstone Mudstone Pumice 14 REVISION 1. Label the layers of the Earth. 2. What are the parts on the Earth’s surface that move causing earthquakes and volcanoes? ____________________________________ 3. Explain how a SEDIMENTARY rock is formed. W______________ creates s_________________. These are e_______________ by wind or water and moved. When the s_______________ are d___________________, they form layers. These are c_________________ together to form S________________ rocks. 4. Explain how a METAMORPHIC rock is formed. I________________ or S____________________ rocks are changed by extreme _______________ or ______________. Metamorphic rocks are much d______________ than the starting rocks. Examples: L___________________ is turned into ___________________. G___________________ is turned into ___________________. 5. Explain how an IGNEOUS rock is formed. All rocks start out as _________________ from inside the Earth’s ________________. If this cools ________________ underground, _________________ crystals form, e.g. G_______________. If this cools fast ___________ ground, ______________ crystals or no crystals form. There may be g____ h________ e.g. P___________. 15 6. Explain how weathering causes rocks to break down. Rain is slightly a___________________. This causes rocks to ___ _______________ _______________________________________________________________ Biological weathering is from __________________ and ___________________. These cause ____________________________________________________________ Ice _____________________________________________________________ ________________________________________________________________ ________________________________________________________________ Heat causes rocks to __________________________________________________ ________________________________________________________________ ________________________________________________________________ Wind carries ________________ which acts like ____________________, breaking down rocks. 6. Complete the table: Rock Name Type (sed/met/ig) How to identify Limestone Coal Marble Granite 16 GEOLOGY: EVERYTHING YOU NEED TO KNOW Structure of the Earth 1. The earth is made up of layers. 2. The sections of the surface (crust) that float around on the convection currents are called tectonic plates . All of the geological action (like earthquakes and volcanoes) happens at plate boundaries. Weathering and erosion biological plants and animals acting on rocks, enhancing cracks , increasing water /chemical absorption chemical by water and minerals interacting and changing rock composition physical abrasion or any other process not involving chemical change ice due to expansion of water when forming ice in cracks and crevices wind like sandblasting a rock with particles carried by wind rain acid rain changing rock structure by reacting with chemicals in the rock temperature expansion and contraction of rocks through changing temperatures erosion sediments are removed by wind, water (rivers, seas, lakes, rain) 17 Rock formation: ( local rocks) Sedimentary rocks are made from eroded bits of other rocks. These are transported (by rivers/glaciers/sea) in layers, and cemented together Limestone forms from shells (in seas) Coal forms from plant material (in boggy forests) Sandstone forms from sand (seas/lakes) Mudstone forms from mud (lakes/estuaries) Conglomerate forms from stones and pebbles (in rivers) Igneous rocks start out as molten rock ( magma ). The magma may cool slowly, underground, forming big crystals, e.g. Granite The magma may cool fast above ground , or in water, forming small/no crystals and may have air bubbles in it, e.g. pumice, obsidian . Metamorphic rocks have gone through big changes . Underground the rocks are put under enormous heat and/or pressure . This changes them. Limestone (sedimentary) turns to Marble Granite (igneous) turns to Gneiss 18
