During recent science
lessons, we have been investigating the formation of rocks. Today, we decided to
make our very own rock types; sedimentary, metamorphic and
igneous.
First we discussed how these
rocks were formed. Miss Campbell gave each science group three different types of chocolate bars. Each group then discussed how these could be used to
represent the 3 types of rock. We shared our
ideas and together decided upon a method which we all used.
We knew that
sedimentary rocks were created
from sediment layers under the sea so we cut our chocolate into small pieces
(sediments) and created layers by spreading each bar on
top of each
other.
Then, we applied pressure from above to represent the force of the waves.
After that, it was time to make our metamorphic rocks. We knew that metamorphic rock was sedimentary rock which had been changed by heat and pressure underground. We broke a piece of our sedimentary rock and squashed it into a ball, applying pressure from all angles. This mixed all the layers together!
Eventually, it was time to make our third and final rock. Igneous rocks are formed from molten rock from underground forced up the surface e.g. through volcanoes. Before it cools and turns into granite or basalt, it is soft and runny. To demonstrate this, the children poured the rest of their chocolate onto clingfilm. Miss Campbell and Kru Bee melted the chocolate in boiling hot water. The children enjoyed feeling the melted chocolate (lava or magma) through the clingfilm.
Finally, the time came when each science group was able to assess their work. We studied the three types of rock carefully and felt very proud of the results. Miss Campbell was so impressed with the children, that as a treat, each group was allowed to shared their chocolate rocks as a break time snack!
Can you explain the main rock types to a friend or family member?
What else could we use to represent the formation of different rocks?
