Permeability/ Porosity of Rocks
Energy and Change- Grade:
- 7
- Teacher:
- Kainat Shafi
Porosity determines the storage capacity of a rock for valuable resources like groundwater, oil, and natural gas. I wanted to check the porosity and strength of the rock. What rock would have the highest porosity? If I soak different types of rocks, then they will have different porosities and permeability, affecting the amount of water they can hold. First I will weigh the dry rocks, second I fill paper bowls with water, then wait while the rocks soak for 20 minutes. After that I weigh the wet rocks, and then put them back into the water for 24 hours. Now after 24 hours I weigh them again and record the data. In conclusion, my hypothesis was correct because there was a mass difference between the rock samples. After soaking for the first 20 minutes the rock that absorbed the most water was the limestone, and the rock that had the least amount of absorption was marble. Then after soaking the rock samples for 24 hours, Limestone had still absorbed the most. This could be due to more porosity and adsorption of limestone. In conclusion, my hypothesis was correct because there was a mass difference between the rock samples.
This is an excellent and very well-chosen experiment! Studying how different rocks absorb and allow water to pass through them shows strong scientific thinking and a great understanding of Earth science concepts. You selected a variety of rock types, which makes your comparison meaningful and interesting.
Your research question — examining water permeability and porosity — is something geologists and environmental scientists study in real life. These properties are very important for understanding groundwater movement, construction safety, erosion, and even oil and gas storage.
By comparing these, you demonstrated that rock type and formation process affect how much water a rock can hold or transmit. As your data suggested, limestone often has higher porosity because it forms from sediment and can contain small spaces between particles. Obsidian, on the other hand, cools quickly from lava and has almost no pores.