Table of Contents
What is mafic and felsic lava?
Mafic magmas are low in silica and contain more dark, magnesium and iron rich mafic minerals, such as olivine and pyroxene. Felsic magmas are higher in silica and contain lighter colored minerals such as quartz and orthoclase feldspar. The higher the amount of silica in the magma, the higher is its viscosity.
What is felsic lava?
Felsic lavas are low temperature lavas because lower temperatures are required to keep felsic minerals molten (and if it was hotter it would have incorporated more iron and magnesium in comparison to silica). So, mafic lavas are hot , low in silica and volatiles, and have relatively low viscosity.
How can you tell mafic or felsic?
Mafic vs Felsic The difference between Mafic and Felsic rocks are the silica content present. Since igneous rocks are characterised by silica content in them, mafic is the one with less silica content (approx. 45-55%) while felsic is the one with a greater silica content (approx. 70-90%).
What is mafic lava?
Describes magma that contains lower amounts of silica and is generally less viscous and less gas-rich than silicic magma. Tends to erupt effusively, as lava flows.
What’s the difference between mafic and felsic lava?
Before cooling, mafic lava has a very low viscosity. The below picture is of the mafic rock basalt. Felsic Magmas: The rocks that form from this type of magma are representative of continental rocks. They tend to have high Silicon content, also known as Silica content.
How are mafic and felsic rocks used in chemistry?
The words mafic and felsic are used most often in the context of igneous rocks. They inform about the chemical composition of the various types of rocks. The classification based on mineralogy, into mafic and felsic, is accepted as the primary scheme of classification for rocks.
What makes a felsic volcano a stratovolcano?
The high viscosity of the lava also makes felsic volcanoes highly explosive, causing the lava to “clot” the mouth of the volcano. This builds up pressure until the volcanoes explodes. Felsic lava forms Stratovolcanoes which are tall, steep volcanoes.
Where does the word mafic come from in lava?
The word derives from a composite of the chemical symbols for Magnesium (Ma) and Iron (Fe). This magma has a low viscosity, which allows for gases to escape the volcano, and for the lava flows to erupt calmly and predictably.