Why is granite less dense than basalt?

Granite is less dense than basalt mainly because granite is made up of lighter mass minerals like quartz and feldspars without much in the way of heavier mass, weightier mafic minerals like pyroxenes and hornblende.

What process makes granite?

Granite is formed when viscous (thick/ sticky) magma slowly cools and crystallises long before it is able to reach the Earth’s surface. Granite is a very resistant rock and weathers slowly to form thin soils with many large boulders sticking out – with typical tors forming the hill-tops as in the image below.

What process formed basalt?

Basalts are formed by rapid cooling of basaltic lava, equivalent to gabbro–norite magma, from the interior of the crust and exposed at or very close to the surface. These basalt flows are thick and extensive in which gas cavities are nearly absent.

How are basalt and granite different from?

Igneous rocks are formed by the crystallisation of a magma. The difference between granites and basalts is in silica content and their rates of cooling. A basalt is about 53\% SiO2, whereas granite is 73\%. (Plutonic rock = formed in the earth).

Why is granite less dense than other rock in the mantle?

The average composition is granite, which is much less dense than the mafic rocks of the oceanic crust (Figure below). Because it is thick and has relatively low density, continental crust rises higher on the mantle than oceanic crust, which sinks into the mantle to form basins.

How does granite differ from basalt in composition and texture?

Main Differences Between Basalt and Granite Basalt is a dense, dark, fine grained igneous rock of a lava flow or minor intrusion composed of labradorite and pyroxene. Basalt is darker colored and is composed of mafic. On the other hand, granite is light-colored and is composed of felsic.

Why is granite dense?

1. What do you think causes some rock types to have higher densities than others? (Assuming there are no air pockets in the rock, the types of minerals will determine the density. Granite contains lots of quartz and feldspar – both fairly light minerals, whereas basalt and gabbro are made of heavier minerals.)

Why is granite so hard?

Granite is a strong stone because its mineral grains have grown tightly together during a very slow cooling period. Additionally, the quartz and feldspar that compose it are harder than steel. Granite takes a good polish and resists weathering and acid rain.

Where are basalt formed?

Basalt is the most common composition of lava rocks that cool from magma, liquid rock that rises from the deep Earth at volcanoes. Today basalt is forming at many active rifts, including Iceland, the East African Rift Valley, the Red Sea and the Rio Grande Valley of New Mexico and Colorado.

Is basalt A igneous sedimentary or metamorphic?

Basalt is a dark-colored, fine-grained, igneous rock composed mainly of plagioclase and pyroxene minerals. It most commonly forms as an extrusive rock, such as a lava flow, but can also form in small intrusive bodies, such as an igneous dike or a thin sill.

How does basalt change into granite?

As the magma cools and very slowly hardens, large crystals form, making a coarse-grained rock. Granite and other rocks that form underground may be exposed at the surface through erosion.

Why is granite less dense than other rock in Earth’s mantle quizlet?

Why is granite less dense than other rock in earth’s mantle? It is made of lighter, less dense materials.