Formation of sedimentary rock
I can describe the formation of sedimentary rock and suggest information that can be obtained from its layers.
- Year 9
Formation of sedimentary rock
I can describe the formation of sedimentary rock and suggest information that can be obtained from its layers.
Lesson details
Key learning points
- Water in nature always contains minerals.
- Sediments are deposited when wind or waterways slow down or when glaciers melt.
- Layers of sediment form over many years, leading to compaction.
- Sedimentary rock forms when sediment is buried and compressed, and salts from fluids cement the grains together.
- Strata can be used to create a relative timeline and provide clues to the environment when the sediments were deposited.
Keywords
Sediment - a material deposited by water, wind or ice, such as pebbles, sand, or salts left by evaporation
Deposition - the process of sediment grains settling out (i.e. being deposited) from water or wind as their flow slows, or as ice melts
Compaction - a process where sediment grains become compacted (i.e. squashed closer together) during burial
Cementation - a process by which sediment grains are cemented (i.e. stuck together) by minerals deposited from groundwater, turning the sediment into rock
Strata - layers of rock (i.e. several rock beds) formed by the deposition of sediment
Common misconception
Some pupils think that compaction and cementation are the same processes.
Highlight that compaction is due to pressure while cementation occurs when minerals act as a 'glue' holding sediments together.
Equipment
For teacher tip: 2× large gauge plastic syringes, 2× disposable cups (to use as mixing bowls), sand, water, cement, stirring rod.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Match the keyword to the correct statement.
