Question

question: which list correctly orders the rocks containing the lowest to the highest concentration of ferromagnesian silicates? answer options: select one of four felsic, mafic, ultramafic, intermediate felsic, intermediate, mafic, ultramafic ultramafic, mafic, intermediate, felsic intermediate, ultramafic, mafic, felsic

Explanation:

To determine the correct order, we recall the characteristics of rock types by ferromagnesian silicate (dark - mineral) content:

• Felsic rocks (e.g., granite) have the lowest amount of ferromagnesian silicates, as they are rich in light - colored minerals like quartz and feldspar.
• Intermediate rocks (e.g., andesite) have more ferromagnesian silicates than felsic but less than mafic.
• Mafic rocks (e.g., basalt) have a relatively high amount of ferromagnesian silicates.
• Ultramafic rocks (e.g., peridotite) have the highest concentration of ferromagnesian silicates.

So the order from lowest to highest concentration is felsic, intermediate, mafic, ultramafic.

Answer:

B. Felsic, intermediate, mafic, ultramafic