Admin Table of Contents
- 1 How can you tell if a rock is intrusive or extrusive Why?
- 2 What determines the texture of an igneous rock?
- 3 What two factors determine the composition of an igneous rock?
- 4 What is the Colour of igneous rock?
- 5 How is the texture of an igneous rock determined?
- 6 How are intrusive and extrusive rocks formed?
How can you tell if a rock is intrusive or extrusive Why?
Summary
- Intrusive igneous rocks cool from magma slowly in the crust. They have large crystals.
- Extrusive igneous rocks cool from lava rapidly at the surface. They have small crystals.
- Texture reflects how an igneous rock formed.
What determines the texture of an igneous rock?
The texture of an igneous rock (fine-grained vs coarse-grained) is dependent on the rate of cooling of the melt: slow cooling allows large crystals to form, fast cooling yields small crystals. In addition to texture, igneous rocks may are classified according to their chemical composition.
What two factors determine the composition of an igneous rock?
The two major factors that influence the creation of igneous rocks are the original rock that was melted and the cooling history of the molten rocks.
How can you determine where an igneous rock formed?
Cooling of the magma can occur beneath the surface (plutonic) or on the surface (volcanic). Igneous rocks can be identified by the determination of the composition and texture of the rock. Once these two characteristics have been identified, the Igneous Rock Identification chart is used to identify the rock name.
What are 2 major factors that make metamorphic rocks?
Metamorphic rocks started out as some other type of rock, but have been substantially changed from their original igneous, sedimentary, or earlier metamorphic form. Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors.
What is the Colour of igneous rock?
Felsic igneous rocks, as a whole rock, tend to have light colors or shades: white, pink, light brown, light gray. Mafic igneous rocks, on the whole, tend to be dark colored, commonly black or dark gray.
How is the texture of an igneous rock determined?
Texture determines whether an igneous rock is defined as Intrusive (coarsely crystalline) or Extrusive (finely crystalline). 1. Fig. 3.2: Intrusive igneous rocks form at some depth within the crust due to slow cooling of magma, resulting in formation of large crystals. Individual crystals can be seen with the naked eye.
How are intrusive and extrusive rocks formed?
Igneous rocks are formed by the heating and cooling of molten rock. They are sometimes called Magmatic rock. The cooling of igneous rock will happen under or above the earth’s surface. The molten rock will crystalize and solidify giving the two basic groups of igneous rocks called Intrusive and Extrusive.
Where does the cooling of igneous rock occur?
The cooling of igneous rock will happen under or above the earth’s surface. The molten rock will crystalize and solidify giving the two basic groups of igneous rocks called Intrusive and Extrusive. The difference between intrusive and extrusive igneous rocks is intrusive igneous rocks will form below the earth with the cooling of magma.
How are igneous rocks divided into two groups?
Igneous rocks are divided into two groups, intrusive or extrusive, depending upon where the molten rock solidifies. Intrusive, or plutonic, igneous rock forms when magma is trapped deep inside the Earth. Great globs of molten rock rise toward the surface.