Cave FormationsProject #1
The process of growing pop corn rock is the same process that creates the pop corn formations in caves. In a cave this process involves a weak acid, usually carbonic acid, dissolving limestone and then depositing calcite (or aragonite) on the limestone in the open space.
Growing pop corn rock in a jar is the same process on a much smaller scale. The acid is the vinegar and the pop corn rock is the limestone.
To make pop corn formations grow on your limestone you must first place the pop corn rock in a clean glass jar. Pour white distilled vinegar to cover the rock. Place the jar in a location where it won’t be disturbed and where you can view the action. Let it set, undisturbed, until the vinegar evaporates. It will take about 3 weeks.
As soon as the vinegar is poured on the rock, you will see it start to effervesce (this means the rock fizzes).
Once the vinegar has evaporated, let the rock sit for a few days to harden. Once it has hardened it can be removed from the jar. If the white calcite breaks off, then you can start the process over. It will usually work 2-3 times.
Erosion Project #2
Use a rock tumbler to demonstrate the rates of erosion on different rocks. Acquire samples of different types of rocks such as limestone, sandstone, quartzite, granite, rhyolite, basalt, and marble. Using coarse rock tumbling grit, place the rocks, water, and grit in the rock tumbler barrel and let it roll. Follow the directions for the rock tumbler for polishing rocks.
Check the progress every day and log the changes you see.
The end results should be something like the softer rocks (limestone, sandstone, marble) should wear down much faster than the harder rocks (basalt and granite). Make sure you come to your own conclusions.
Rock Cycle Project #3 - Collecting
Rocks don't form into the three types of rocks and stay there. The Earth is constantly changing and in motion. The rock cycle demonstrates how a rock can start out as one type and change into another.
Any rock can be taken through the cycle. For example, I will start with granite (remember, granite is intrusive).
As granite is exposed on the Earth's surface it starts to weather. Rain and snow and wind all work on breaking the granite down into smaller pieces. As the granite is weathered, the minerals that make up granite-quartz, feldspar, and mica all break down out of the rock.
The mica and feldspar turn to clay minerals and are deposited close to the granite. The quartz is much stronger. It finely ends up along rivers and lakes or oceans as sand. The sand builds up thick layers so the sand on the bottom becomes sandstone. As the sandstone is pressurized it becomes quartzite.
So now lets say the quartzite is exposed to the surface due to weathering. As the quartzite starts to weather, it will become sandstone and can start the process over again. Or the quartzite can be buried in the Earth's crust and go into the mantle to become molten rock which can become granite again.
Not all rocks go through the rock cycle. And not all rocks go through all the stages. For example: a sedimentary rock may weather again and become a new sedimentary rock.