Resources: Class presentation, a selection of rocks to test, sandpaper, nails, small wooden spoons, water, pipettes, a bowl of water and a microscope or magnifying glass.
Support Handout (1): A selection of pictures of rocks for the children to cut out and sort into the correct area on the table.
Core Handout (2): A space for the children to write down a use for 6 different types of rock.
Stretch Handout (3): Lines for the children to explain the properties of igneous, sedimentary and metamorphic rocks.
Enquiry Approach - Comparative / fair testing
Conducting a test that controls all but one variable to answer a scientific question.
Enquiry Skill - Observing and measuring
Using the senses and taking measurements, using a range of equipment, to make observations about a scientific enquiry.
Recap on the children’s previous learning by asking the following recall questions: what is igneous rock? What is the difference between intrusive igneous rock and extrusive igneous rock?
Use the lesson presentation to teach the children about the formation of sedimentary and metamorphic rocks. The children will then apply their knowledge to compare and group together different kinds of rocks. Before the children carry out their tests, be sure to discuss how they can ensure they are carrying out a fair test.
Career Film: Take a tour around Widemouth Bay and The Etches Collection Museum on the Jurassic Coast to find out about Rob McLaverty's job. Rob works as a Geologist for Nuclear Waste Management Services.
Expert Film: This is Rob McLaverty. Rob works as a Geologist at Nuclear Waste Services. Rob explains why it is important to understand why and how rocks are formed to do his job as he explores sites to build a Geological Disposal Facility.
The children will carry out some tests on a selection of rocks to investigate their durability, permeability and density. They will also use a microscope to see if the rocks contain crystals.
Durability? - The children will test how hard or soft the rocks are by scratching them with different items (for example, sandpaper, a nail and a wooden spoon) to see if the rock starts to crumble off.
Permeability? - The children will test whether water will soak into the rocks by dropping a small amount of water onto the rocks.
Density? - The children will test how dense their rocks are by seeing if they float or sink.
Crystals? - Using a microscope or magnifying glass, can the children see any crystals embedded in the rocks?
Using this knowledge, what uses do these rocks have? What could they be used for?
Challenge Task: Once the children have carried out their tests, ask them to sort the rocks into igneous, sedimentary and metamorphic rock and explain their properties.
Discuss the children’s results and their grouping. What could these rocks be used for in everyday life? Do the properties of the rocks enable them to sort them into igneous, sedimentary and metamorphic rocks?
Sedimentary and metamorphic rocks are two of the three main types of rocks found on Earth, alongside igneous rocks. They form through different processes and have distinct properties.
Sedimentary rocks form from the accumulation and cementation of small particles such as sand, silt, or clay, or from the precipitation of minerals from water. These particles are usually derived from pre-existing rocks that have been weathered and eroded, and are transported by wind, water, or ice to a new location where they settle and are eventually compacted and cemented into a solid rock. Some common types of sedimentary rocks include sandstone, shale, and limestone.
Properties: The properties of sedimentary rocks vary depending on their composition and texture. They are typically layered and can contain fossils or other evidence of past environments. Sedimentary rocks are often porous and can hold water or oil, which makes them important reservoirs for natural resources such as groundwater and fossil fuels. The porosity and permeability of sedimentary rocks also make them important for the study of groundwater resources and the development of water wells.
Metamorphic rocks form from the alteration of pre-existing rocks due to changes in temperature, pressure, or chemical environment. This process, called metamorphism, causes the minerals in the original rock to recrystallise and reorganise into new minerals or textures. Metamorphism can occur due to tectonic activity, contact with hot magma, or the burial of rocks in the Earth's crust. Common types of metamorphic rocks include marble, slate, and gneiss.
Properties: The properties of metamorphic rocks are influenced by their original composition and the degree and duration of metamorphism. They can exhibit a range of textures, from foliated (layered) to non-foliated, and often have a distinct crystalline structure. Metamorphic rocks are typically harder and more resistant to weathering than sedimentary rocks, making them useful for construction and decorative purposes.
In summary, sedimentary and metamorphic rocks form through different processes and have distinct properties. Understanding the formation and properties of sedimentary and metamorphic rocks is important for a wide range of applications, from natural resource exploration to building and construction.