Question

Compared to felsic magmas, ultramafic magmas have higher silica concentrations, crystallize at higher temperatures, have higher sodium and potassium concentrations, have higher viscosity, and have lower iron and magnesium concentrations?

1) True
2) False

Answer 1

Ultramafic magmas actually have lower silica concentrations, higher crystallization temperatures, lower sodium and potassium concentrations, higher viscosity, and higher iron and magnesium concentrations compared to felsic magmas.

Step-by-step explanation:

Ultramafic magmas actually have lower silica concentrations, crystallize at higher temperatures, have lower sodium and potassium concentrations, have higher viscosity, and have higher iron and magnesium concentrations compared to felsic magmas. Ultramafic magmas are rich in iron and magnesium, which gives them a dark color and a mafic composition. Felsic magmas, on the other hand, have a higher silica content and are lighter in color.