WebThis gives the magma lots of time to react with the surrounding country rock. The mafic magma tends to assimilate felsic rock, becoming more silica-rich as it migrates through the lithosphere and changing into intermediate or felsic magma by the time it reaches the surface. This is why felsic magmas are much more common within continents. WebGranitic magmas are rich in silica and often contain up to several percent gas by weight. As these magmas cool, the silica starts to connect into complex molecules. This gives the magma a high viscosity and causes it to move very sluggishly. Lava Domes. Sluggish rhyolitic lava can slowly exude from a volcano and pile up around the vent.
Magma that cools below Earth’s surface forms - Weegy
WebAug 1, 2001 · Summary. It was once thought that granitic magma was so viscous that it would take hundred of millions of years for granitic rocks to form. However, recent … WebFeb 11, 2024 · There are three major types of magma. Basaltic (or mafic) magma predominates in nonexplosive volcanic eruptions. It is a high-temperature magma (1,200 °C [about 2,200 °F]) characterized by … diane lane beauty tips
Earth Science - Chapter 7 Volcanoes Flashcards Quizlet
WebMar 13, 2024 · Mafic magma has relatively low silica content, roughly 50%, and higher contents in iron and magnesium. This type of magma has a low gas content and low viscosity, or resistance to flow. Mafic magma also … WebApr 5, 2024 · Basaltic magma contains between 45 and 55 percent silicon dioxide and is high in magnesium, iron and calcium, while granitic magma contains between 65 and … WebIn igneous rock: Origin of magmas. Granitic, or rhyolitic, magmas and andesitic magmas are generated at convergent plate boundaries where the oceanic lithosphere (the outer layer of Earth composed of the crust and upper mantle) is subducted so that its edge is … citel online work