Q:

Where can igneous rocks be found?

A:

The most common type of igneous rock, basalt, also known as malfic rock, can be found on oceanic plates at divergent plate boundaries. Intermediate and felsic igneous rocks show up along continental margins, as well. Because igneous rocks form from the cooling of lava and magma, they can be found around areas where volcanic activity is or has been present.

Igneous rocks form from magma and lava that cools and solidifies. As this happens, the magma or lava crystallizes, creating igneous rock, of which there are many variations. Igneous rocks come in two types, extrusive and intrusive. Igneous rocks are split into these two categories based upon how they cool. Extrusive rocks form form lava on the surface that crystallizes, forming finely grained crystals, but intrusive rocks instead cool and crystallize below the surface of the earth from magma. They cool at a slower rate, forming large, coarsely-grained crystals. There is an unwritten third type of igneous rock that is technically extrusive, but it differs from other extrusive rocks because the lava cools instantly, forming a glass-like texture.

There are many ways scientists describe igneous rocks, which have four different types of mineral composition: felsic, intermediate, mafic and ultramafic. Texture is also an important characteristic that classifies igneous rocks and is determined by the size of its grains or crystals. These grain types are listed as pegmatitic, phaneritic, porphyritic, aphanitic, glassy, vesicular, frothy and pyroclastic.

Sources:

  1. ncdcr.gov

Is this answer helpful?

Similar Questions

  • Q:

    Where can metamorphic rocks be found?

    A:

    Metamorphic rocks are most often found in mountainous regions though they can be seen wherever there are signs of geological upheaval in an area. This type of rock is formed by the transformation of another rock type, a change that is usually triggered by tremendous heat, pressure or other violent phenomena. The forces that cause metamorphic rocks to form are so great that they change not only the appearance but also the chemical composition of an existing rock.

    Full Answer >
    Filed Under:
  • Q:

    What is a bend in a layer of rock called?

    A:

    A bend in a layer of a rock is known as a fold, which is caused by compression that leads to rocks either bending or breaking. Folds that produce a type of upward arch are known as an anticline, according to Education.com.

    Full Answer >
    Filed Under:
  • Q:

    What are igneous rocks used for?

    A:

    Igneous rocks are often used for construction because of their durability. Igneous rocks can also be separated to access the various valuable metals and minerals inside them. Igneous rocks form as magma comes to or near the surface of the Earth; cooling and hardening because of its distance from the inner parts of the Earth where magma forms.

    Full Answer >
    Filed Under:
  • Q:

    How do igneous rocks form?

    A:

    Igneous rocks are formed when magma crystallizes and solidifies. After this transition from liquid to solid, igneous rocks are classified as either intrusive or extrusive.

    Full Answer >
    Filed Under:

Explore