Mafic

High school (ages 12+)
Environment & Earth

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/mafic

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the mineralogical composition?Rich in olivine, pyroxene, amphibole, biotite, and calcium-rich plagioclase feldspar
2. What is the primary rock types?Extrusive: Basalt. Intrusive: Gabbro, Diabase
3. What are mafic rocks and why are they called "dark and heavy"?Mafic rocks are dark, iron‑rich rocks that come from the Earth's mantle. They are heavy because they contain lots of magnesium and iron minerals like olivine and pyroxene.
4. Where do mafic rocks come from inside the Earth?They form when the mantle's peridotite melts. The melt rises as basaltic magma at places like mid‑ocean ridges or subduction zones.

Silicate Minerals: Minerals containing silicon and oxygen, forming the vast majority of Earth's crustal rocks.
Plate Tectonics: The theory describing the large-scale motion of Earth's lithosphere, driven by convection currents in the mantle.
Subduction: The process where one tectonic plate slides beneath another, typically oceanic crust under continental crust.