Science Sunday ~ Rocks Week 2

This week we focused on the three types of rocks ~ sedimentary, igneous and metamorphic. To demonstrate how these rocks are formed we made edible rocks.  I found the information here.  Warning ~ these contain LOTS of sugar!

We started out talking about sedimentary rocks which are formed when layers of sand, small bits of rock, clay, plants, bones and mud are piled on top of each other and eventually get compressed and harden into rocks.  Sedimentary rocks are often formed in river and lake bottoms.   I asked the kids why water was important?  Emily’s answer ~ The water carries the “stuff” down the river.

To demonstrate how sedimentary rocks are formed we used the following to represent the different layers ~ bread (dirt), graham crackers (sand), crunchy peanut butter (mud with small rocks in it), strawberry jelly (dried leaves and twigs) and grape jelly (bones).  We put a layer of each on our bread

 

and the kids compressed their sedimentary “rocks”.

Next up Igneous rocks which are formed from melted rock.  I asked the kids what would be hot enough to melt rock?  The answer ~ a volcano.

   

To make our edible igneous rocks we used butterscotch and chocolate chips to represent the different kinds of minerals founds in rocks. 

 

Melted them in the microwave to show that once it is heated you can no longer see the individual minerals (chips). 

We put our hot magma on waxed paper and stuck them in the fridge to cool.

 

The last rock we talked about was metamorphic rocks which are formed when rocks and minerals have been heated and compressed, forming a new rock.  The process does not melt the rocks completely like igneous rocks it just transforms them into denser more compact rocks.

For this experiment we used sugar cookie dough and 3 colors of food coloring.  We divided the dough into 3 equal sections and added 5 drops of different food coloring to each section. 

We rolled balls out of each color, and the kids compressed them.

Then we baked them (heat)

and enjoyed our metamorphic “rocks”.

            

For more fun with science, check out Science Sunday at Adventures in Mommydom.

~Cindy