GEOLOGY

Detailed explanation-1: -Second, silica content affects how easily magma flows. Magmas that are rich in silica do not flow nearly as easily as magmas that are poor in silica. Because of this, silica-rich magmas are more likely to remain below the Earth’s surface, at shallow depths, rather than flowing freely out onto the surface.

Detailed explanation-2: -Because it is more difficult for dissolved gas to escape from more viscous magma, higher silica magmas generally erupt more explosively.

Detailed explanation-3: -Both the temperature and mineral content of magma affect how easily it flows. The viscosity (thickness) of the magma that erupts from a volcano affects the shape of the volcano. Volcanoes with steep slopes tend to form from very viscous magma, while flatter volcanoes form from magma that flows easily.

Detailed explanation-4: -Magmas with high silica content have a high viscosity (resistance to flow) and are generally more explosive when eruptions occur. All magmas also contain some degree of trapped gasses (CO2 & H2O ). The more trapped gas the more violent the explosion. All magma that reaches the surface can be classified as Lava.

Detailed explanation-5: -Low-silica magmas are typically formed by partial melting of mantle rocks beneath mid-ccean ridges or at “hot spots” like Hawaii. These magmas erupt as basalts or intrude as gabbro, and are far less viscous. Eruptions are generally effusive.