rock samples BP Educational Service

Transcription

1 rock samples primary teacher s notes BP Educational Service

2 About Rocks Our planet Earth is made up of four main layers: 1. The crust an outer layer made of rock and it carries the land and ocean areas 2. The mantle under the crust and is liquid rock 3. The outer core mostly liquid iron 4. The inner core mostly solid rock But what exactly are rocks? The ground on which we walk, build or grow gardens is made of rock. Rocks are solid mixtures of minerals. Some rocks are made of only one mineral, but most have more than one kind. They are not necessarily hard loose sand and wet clay can be considered as rocks. They come in all sorts of shapes, sizes and textures. Rocks can be grouped by the way they are formed into sedimentary rocks, metamorphic rocks and igneous rocks (these are described on the following pages).. Did you know? By reading the record of the rocks, geologists have learned so much about past climates, the geography of Earth and about the makeup of our planet

3 The Rock Cycle Igneous rocks Exposed sedimentary rock Cooled above ground Exposed igneous rock Cooled below ground Exposed metamorphic rock Uplift Weathering and wearing away Sediments Sea Pressure Uplift Melting Metamorphic rocks Heat and pressure Sedimentary rocks Magma Over millions of years, weather, heat and pressure change old rocks and minerals into new rocks. This is a really good example of recycling! It is called the rock cycle and you can see what happens on this diagram. There is no starting point in this cycle. 1

4 Sedimentary Rocks All rocks break down at the surface of the Earth: it is called weathering when caused by changes in the temperature or by chemicals as in acid rain it is called erosion when it s caused by movement, e.g. wind, river, glaciers. These broken down rocks or sediments are washed away and settle as layers As more layers settle, air and water are squeezed out and the layers become cemented or stuck together forming a solid rock Different layers called strata give a valuable record of the Earth s history Many sedimentary rocks are made up of bits of other rocks, and some contain the remains of living things fossils, such as sea shells and corals Oolitic Limestone Limestone Desert Sandstone Mudstone Chalk Conglomerate Sandstone 2 Sedimentary rocks are the softest of the rocks, are easy to cut and shape and are very useful in our lives today; as building materials, as a fuel, or in fertilisers, through to being carved for ornaments. Did you know? Many fossils of plants and animals that are now extinct such as dinosaurs are found in sedimentary rocks.

5 Metamorphic Rocks The word metamorphic means change and this describes how the rocks change into another type or form e.g. like when dough is baked in an oven, it doesn t melt, but changes into bread The layers in the sedimentary rock disappear as it takes a new form Rocks change when they are heated and squeezed deep underground An example is when limestone (a sedimentary rock) turns into marble (a metamorphic rock) Marble is used today for many things, from floor tiles, gravestones, to beautiful sculptures (the ancient Greeks and Romans used marble for their sculptures). As the forces underground increase, muddy rocks turn into slate This can be broken into thin layers and is used for roofing and flooring tiles When there are medium forces and temperatures beneath mountainous areas, rocks like schist are formed. Where there is greatest force and temperature, rocks such as gneiss (sounds like nice ) are formed. White Marble Slate Banded Gneiss Mica Schist Did you know? These rocks get their name from the Greek words meta and morphe meaning change of form. 3

6 Igneous Rocks These rocks are formed when the metamorphic rocks melt This melted, liquid rock (called magma) can rise up to the surface in volcanic eruptions If the molten rock spurts out of the volcano as lava, it cools very quickly and tiny minerals are formed in the rock - a good example is basalt (you can see a wonderful example of this in The Giant s Causeway in Northern Ireland!) If the molten rock cools and hardens slowly underground, then rocks with larger minerals are formed - such as granite Granite is found in many beautiful colours and is often used as building stones, or polished worktops. Crushed granite is used for road building material. Did you know? Dolerite Volcanoes can be on land or beneath the sea. Gabbro 4 Some are extinct and no longer likely to erupt, others can lie dormant (sleeping) for many years, then suddenly erupt; others erupt regularly like in Iceland and Hawaii. Amygdaloidal Basalt Granite

7 Rocks from Space The oldest rocks found on Earth have not been formed here. They have come from outer space and are called meteorites. About 20,000 meteorites fall to Earth every year. Most are never actually found as they fall into the sea or on deserts. Some large meteorites explode as they hit the ground, making great craters and melting the rocks around them into glassy stones called tektites Did you know? Meteorites found in Antarctica are known to have come from the Moon, others are thought to be from Mars and some appear to contain fossilised bacteria! Moon Rock When astronauts landed on the Moon they collected samples of moon rock After studying them back on Earth, geologists found that the most common type of rock on the moon is a variety of basalt found here on Earth too! 5

8 Suggested Activities Make a collection of a variety of materials found in the back garden (include items such as brick, wood, glass, stones, fossils): add to 6 rock samples from the rock box (such as granite, gneiss, shelly limestone, red sandstone, conglomerate) ask the pupils to first sort into natural and manufactured groups. Then ask them to sort the things that came from out of the ground into 3 or 4 subsets. Leave them to decide how to sort (colour/shape/size/texture etc.) have a group discussion over different ways to sort. Granite Gneiss Using secondary sources find out more: produce a rock fact file make models of the rock cycle investigate local area use hand lenses to observe and sketch surfaces of each rock sample carry out a test for their wear using sandpaper rub each rock with the same force and record observations Shelly Limestone Red Sandstone Conglomerate test for porosity, observe and record results in a table discuss effect of water freezing and thawing, what would happen to the surfaces of these rocks? 6

9 Try to classify the rocks from the rock box into their type look for: sedimentary mostly layered, non-crystalline, soft metamorphic mostly crystalline, layered, hard igneous mostly crystalline, not layered, hard. Read out the different methods of rock formation and encourage the pupils to explain each process in their own words either verbally or written Ask the pupils to draw and label their own rock cycle. Make a large wall poster add labels of names of different types of rocks. Early humans made their own coloured paints by crushing different coloured rocks: collect rocks such as chalk, coal, brown clay etc. scrape off small pieces and grind with a pestle and mortar collect the ground pigment into egg cups or small plastic containers add a few drops of oil to turn them into a paste and hey presto coloured paints. Make salt crystals by mixing 200 grammes of table salt into 500 ml of hot tap water: stir to dissolve and pour into a shallow dish and leave for several days when the water has evaporated, fine salt crystals will have formed at the bottom of the dish. Make edible rocks with marzipan or icing sugar: add water and mix into a thick paste sculpt into different rock shapes and leave to dry use food colouring to look like real rocks! 7

10 Research, discussion and questions Rock exists naturally beneath all surfaces your house, your garden, your street, your school. The many different types of rocks are formed in different ways. Can you answer these questions? (All answers to questions can be found in this booklet.) Of what is the centre, inner core of the Earth made? What is the outer core? What is the mantle? Of what material is the crust made? Of what are rocks made? How are sedimentary rocks formed? Name one. How are metamorphic rocks formed? Name one. How are igneous rocks formed? Name one. What is the recycling of rocks called? Why are sedimentary rocks sometimes called second hand rocks? What does the word metamorphic mean? What is magma? Name two rocks that are porous (if you don t know, test by dripping water droplets onto samples from the box) Name two rocks that are not permeable Name a very hard rock made of large minerals What was the most common type of rock found on the moon? How are tektites formed? Give two properties that make marble useful for statues Give two properties that make slate useful for roofing Give two properties that make granite useful for worktops 8

11 Crater Deposition Erosion Fossils Igneous Lava Magma Mantle Metamorphic Meteorites Minerals Molten Porous Pressure Sedimentary Tektites Transport Weathering Difficult words explained A bowl-shaped hollow in the ground, made by a meteorite, or at the top of the volcano where it has erupted The dropping of rock fragments to form sediment Weak surface is worn away by wind, moving water or moving ice The remains of plants and animals that have hardened into rock after a very long time Formed from molten rock that has cooled and hardened Hot liquid rock that comes out of a volcano and becomes solid as it cools down Red hot liquid rock that is still beneath the surface of Earth The layer of rock under the Earth s crust A change of shape and form to something else Rocks either travelling through or coming to Earth from outer space The most common solid materials found on Earth regular compounds of chemicals Melted, made into liquid Soaks up water into tiny spaces in the rock The force on or against a surface by something pressing on it Formed when layers of sediment are squashed together and stuck together Small smooth glassy stones formed by meteorites and exploding and melting rocks around them The ways in which rock fragments are carried from one place to another by moving water, ice or wind Exposed rock is weakened by the temperature changes and chemicals in the atmosphere 9

12 Curriculum links These notes accompanying the fossils box can be linked to support several curriculum areas for primary age groups. The key curriculum areas in England & Wales Geography Science - enquiry skills and knowledge and understanding of places, patterns and process and environmental change and sustainable development - breadth of study to local environment and fieldwork investigations - enquiry and investigative skills - materials and their properties, classifying, changing materials, useful products, and separating materials - physical processes, forces and motion The key curriculum areas in Scotland Environmental studies: Society - enquiry skills, knowledge and understanding of people and physical environment and interaction Science - investigating skills, knowledge and understanding of earth and space, materials from the earth and changing materials - energy and forces properties and uses of energy and forces and effects BPES has a range of other resources. For your free catalogue please contact us at: BP Educational Service (BPES), PO Box 105, Rochester, Kent ME2 4BE Tel: +44 (0) Fax: +44 (0) bpes@bp.com Alternatively, visit our website at Acknowledgments Grateful thanks are extended to Peter Kennett and the Earth Science Teachers Association (ESTA). ESTA publishes a quarterly activity sheet for primary teachers and can be contacted at: ESTA, c/o The Geological Society, Burlington House, London W1V 0JU. Website: esta-uk.org BP is a member of the U.K. Offshore Operators' Association (UKOOA). UKOOA supports the Earth Science Education Unit which exists to provide Earth Science INSET in both primary and secondary schools and teacher education institutions throughout the country. The workshops all involve practical and investigative work. Such INSET is free apart from the travel costs of your local ESEU facilitator. For further information please contact Bernadette Callan: eseu@keele.ac.uk, tel: web: The website is compiled by teachers of physics, biology and chemistry, with ESTA advice, and contains many ideas for practical and investigative work in Earth Science. The paper used for this leaflet meets the strictest environmental standards set by the Nordic Swan Council and is fully recyclable.the pulp used to produce the paper is generated locally, fully sustainable and bleached without the use of elemental chlorine. BP International Ltd 2006