Felsic rocks are characterized by their high silica content. This means they have a relatively high concentration of silicon (Si) compared to other elements. Here's a breakdown of their relative element concentrations:

High Concentrations:

* Silicon (Si): The dominant element, typically making up around 60-70% of the rock.

* Oxygen (O): Another major component, present in large amounts due to the abundance of silica.

* Aluminum (Al): Found in significant amounts.

* Sodium (Na): Relatively high compared to mafic rocks.

* Potassium (K): Also relatively high compared to mafic rocks.

Moderate Concentrations:

* Calcium (Ca): Present in moderate amounts.

* Iron (Fe): Present in smaller amounts than in mafic rocks.

* Magnesium (Mg): Present in smaller amounts than in mafic rocks.

Low Concentrations:

* Titanium (Ti): Present in trace amounts.

* Other trace elements: Found in very small quantities.

Key takeaway: The high silica content of felsic rocks is reflected in their relatively high concentrations of silicon, oxygen, aluminum, sodium, and potassium. They have lower concentrations of iron, magnesium, and titanium compared to mafic rocks.