Formation Of Rocks
Overview
The ground beneath your feet is not as still as it looks. Granite kitchen worktops, the slate on a roof, the limestone in a cathedral and the marble of a statue all began as something else and were made over by heat, pressure, water and time. Geologists group every rock on Earth into just three families, and each family tells the story of how it was born. Learn to read those stories and you can pick up almost any rock and say where it came from.
In this lesson you will see how igneous, sedimentary and metamorphic rocks form, and how the rock cycle links all three so that one rock type can slowly become another. You will also meet permeability, the property that decides whether water soaks through a rock or runs off it. These ideas underpin everything that follows in this unit, from where we mine metals to where groundwater is stored.
Objectives
- 1.1.1 Describe the formation of named igneous, sedimentary and metamorphic rocks, limited to: (a) igneous: granite and basalt (b) sedimentary: limestone, sandstone and shale (c) metamorphic: marble and slate.
- 1.1.2 Describe and interpret the rock cycle, limited to: (a) weathering (b) erosion (c) transportation (d) sedimentation (e) compaction (f) cementation (g) crystallisation (h) deposition.
- 1.1.3 Define permeability as the ability of water to pass through the pore spaces of rock and soil.
- 1.1.4 Classify rocks as permeable and impermeable, limited to: (a) permeable: most sedimentary rocks (limestone and sandstone) (b) impermeable: igneous, metamorphic and some sedimentary rocks (shale).
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Lesson Evaluation
Congratulations on completing the lesson on Formation Of Rocks. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which rock type is formed when molten magma cools and solidifies? A. Sedimentary B. Metamorphic C. Igneous D. Fossil Answer: C
- A rock contains visible large crystals and no layers. It most likely formed by: A. Rapid cooling of lava at the surface B. Slow cooling of magma underground C. Compaction of sediment D. Heat and pressure on shale Answer: B
- Which of the following is an impermeable sedimentary rock? A. Limestone B. Sandstone C. Shale D. Granite Answer: C
- Limestone is changed into marble by: A. Weathering and erosion B. Compaction and cementation C. Heat and pressure D. Melting and crystallisation Answer: C
- Permeability is best defined as the ability of: A. A rock to resist scratching B. Water to pass through the pore spaces of a rock C. A rock to contain fossils D. Crystals to form on cooling Answer: B
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