Why is the Pacific Plate sliding under instead of Japan?
Why does the Pacific Plate slide underneath the North American Plate near Japan? To assist with this questions - there are 2 samples of rocks, one found from the ocean floor and one found on the continent.
The dark rock is made of Basalt and is found on the ocean floor. The lighter rock is Granite and is found on the continents.
First examine the crystalline structure with a hand lens and note any observations you may find.
The dark rock is made of Basalt and is found on the ocean floor. The lighter rock is Granite and is found on the continents.
First examine the crystalline structure with a hand lens and note any observations you may find.
Calculating the rocks density lab
In this lab, students are investigating the density of two different types of rocks; Granite and Basalt.
To examine the density of the rock,
The results are listed below.
To examine the density of the rock,
- Measure the mass of the rock using a triple beam balance.
- Measure the volume of the rock by capturing the water spilled out of a beaker filled to the brim with water.
- Measure the displaced water using a graduated cylinder.
- Record your findings and calculate the rocks density by taking the ratio of mass to volume.
The results are listed below.
Data Analysis:
- Granite's density is 2.7 g/mL
- Basalt's density is 2.9 g/mL
- Basalt is more dense than Granite
Conclusion:
As we see here, Basalt from the ocean floor is slightly more dense than the Granite continental crust - this could very well explain why the Pacific Plate subducts below the North American Plate that Japan sits on - which explains why the fault angled below Japan instead of the other way around.
As we see here, Basalt from the ocean floor is slightly more dense than the Granite continental crust - this could very well explain why the Pacific Plate subducts below the North American Plate that Japan sits on - which explains why the fault angled below Japan instead of the other way around.