Explore rock formation through simple science experiments.
Rock formation occurs through a process called the rock cycle. Three rock types are possible: igneous, sedimentary and metamorphic. Each rock type forms in similar ways, but consists of varying internal structures. Simple experiments have been devised for visualizing and experiencing rock formation, especially for geological studies.
The Rock Cycle
Rock experiments help students understand the rock cycle. Igneous rock is formed directly from volcanic magma. Sedimentary rock forms from compacted and shattered pieces of igneous rock. Metamorphic rock manifests from both igneous and sedimentary rock. Heat and pressure forced upon igneous and sedimentary rock creates a metamorphic rock. The rock cycle continues as a natural process of the Earth's crust. The Earth's tectonic plates subduct and crash against one another, creating new rocks from magma deep in the Earth's structure.
Rock Structure Experiment
A rock's surface may look impenetrable, but it is actually highly absorbent. This absorbency tendency demonstrates how easily a rock can shatter and change from one rock type to another. Weigh a dry, pumice rock and record the results. Place the rock in water for an hour. Remove the rock and weigh it again. Allow the rock to rest in the open air. Weigh the rock repeatedly at one hour intervals. The experiment should indicate that the pumice rock absorbed water when submerged, and subsequently the water evaporated once the rock was left in open air. Students can also try other types of rock, comparing the different absorbency amounts.
Rock Stratification Experiment
Many sedimentary rocks have striations, or layers. However, sedimentary rock is a conglomeration of different rock pieces compacted together, so defined layers seem inconceivable. Layer development is explained through an experiment using a rubber ball and rice. Fill a jar 3/4 full with rice. Press and bury a rubber ball within the rice. Cover the jar and shake it. After shaking, the ball should maneuver to the top of the rice. Rocks of the same size tend to segregate from smaller or larger sized rocks, congregating together and forming layers.
Expanding Ice Experiment
Ice easily breaks rock, especially if the ice is embedded within the rock's interior structure. Breaking igneous and metamorphic rock creates the sediment necessary for forming sedimentary rock. Ice infiltrates any type of the three rock formations. An expanding ice experiment provides a visual for students. A glass bottle acts as the rock form and water inside becomes the ice. Pour water into a glass bottle and tightly cap the opening. Place and seal the bottle in a strong freezer bag. Place the bottle and bag combination in the freezer during the evening and remove it in the morning. The glass should have shattered from the expanding ice formation, demonstrating rock shattering into sediment for sedimentary rock formation.
Tags: sedimentary rock, igneous sedimentary, glass bottle, igneous sedimentary rock, pumice rock, rock creates
