Answer:
The oceanic crust is formed by partial melting of the mantle at mid-ocean ridges. The continental crust is formed even more cycles of partial melting over time, resulting less dense rocks.
Explanation:
The mantle, oceanic crust, and continental crust all have different compositions due to a process called partial melting.
This is where you start to melt a rock, but don´t melt it all the way.
When you partially melt a rock, certain chemical elements tend to stay in the solid rock while others tend to go into the melted part.
As a result, the rock that forms from that melt is less dense than the original rock.
If you then partially melt that rock, you get a rock that is even lighter.
Answer:
Explanation:
Eras are made up of eons, but hours are made up of minutes. Eons are made up of eras, but minutes are made up of hours. Eras are not even divisions of time, while minutes are. Eons are even divisions of time, while hours are not.
Many scientists are concerned that the Ogallala aquifer in the United States is being depleted at an alarming rate. The statement that is correct and would state the most likely be a major effect of this aquifer running dry is choice A. It states that many crops would die because irrigation water would be limited.
