What are the characteristics of metamorphic rocks?
Metamorphic rocks were once igneous or sedimentary rocks, but have been changed (metamorphosed) as a result of intense heat and/or pressure within the Earth’s crust. They are crystalline and often have a “squashed” (foliated or banded) texture.
What four characteristics determine the type of metamorphic rock?
Factors that Control Metamorphism
- Chemical Composition of the Protolith. The type of rock undergoes metamorphism is a major factor in determing what type of metamorphic rock it becomes.
- Temperature.
- Pressure.
- Fluids.
- Time.
- Regional Metamorphism.
- Contact Metamorphism.
- Hydrothermal Metamorphism.
What type of rock is limestone?
sedimentary rock
How does the rate at which magma cools affect the texture of igneous rock?
The factor that affects the size of the crystals and the texture of the rock is the cooling rate of the molten rock or magma. If the magma cools rapidly, the crystal formed is very small. On the other hand, if the magma cools slowly, the crystal formed is large. This rock has a coarse-grained texture.
What is the relationship between the rate of cooling of igneous rocks and crystal size?
As the rate of cooling increases, crystal size decreases. This means that something which cools very quickly will have smaller crystal formations, and something which cools slowly will have larger crystal formations. This is easily seen in igneous rock, which may cool at variable rates.
How does the amount silica affect the color of igneous rock?
Both glass and quartz are colourless when pure. The more silica you have in a rock, the paler it tends to be. Felsic rocks have high silica content, because they contain lots of quartz and another mineral called feldspar. These are rocks like basalt, which is very darkly coloured.
What other factors influence the texture of igneous rocks?
Texture of igneous rocks defines the shape, size and mutual relationship of the constituent minerals. The texture in igneous rocks depends on the following four factors: i) Viscosity of magma ii) Rate of cooling iii) The order of crystallization of the constituent minerals.
How do you identify different types and textures of igneous rocks?
Igneous rocks may be simply classified according to their chemical/mineral composition as felsic, intermediate, mafic, and ultramafic, and by texture or grain size: intrusive rocks are course grained (all crystals are visible to the naked eye) while extrusive rocks may be fine-grained (microscopic crystals) or glass ( …
What factors can affect the texture of a sedimentary rock?
The Rock Cycle, Igneous Rock
| Question | Answer |
|---|---|
| What do the size, shape, and positions of the grains that make up a rock determine? | the rock’s texture |
| What factors can affect the texture of a sedimentary rock? | the size of the grains that make up the rock |
Which of the following distinguishes igneous rocks from other rock types?
Igneous rocks can be distinguished from sedimentary rocks by the lack of beds, lack of fossils, and lack of rounded grains in igneous rocks, and the presence of igneous textures.
What are some examples of intrusive igneous rocks?
Typical intrusive bodies are batholiths, stocks, laccoliths, sills and dikes. Common intrusive rocks are granite, gabbro, or diorite. The central cores of major mountain ranges consist of intrusive igneous rocks. When exposed by erosion, these cores (called batholiths) may occupy huge areas of the Earth’s surface.
What is the similarities of intrusive and extrusive igneous rocks?
Intrusive and extrusive igneous rocks are alike in that they are both formed from the cooling and crystallization of molten substance (magma and lava,…
Is granite plutonic or volcanic?
Basalt and obsidian are volcanic rocks; granite is plutonic. Ask students how they can determine this. The answer is: plutonic rocks (such as granite) cool slowly in a relatively undisturbed environment permitting the growth of large mineral crystals which can easily be seen by the unaided eye.
Which list of igneous rocks is in order of increasing silica content?
When magma does reach the surface during a volcanic eruption, the rocks that form there are called lavas or volcanic rocks. The basic classification is the same as for plutonic rocks: with increasing silica content, they include: basalt, andesites, dacites, rhyolite, pumice and obsidian.
Is Granite stronger than basalt?
Basalt weathers faster than granite because it is not as hard and it’s easier for outside substances to impact and manipulate its structure.
Is granite a mafic?
Granite and rhyolite are considered felsic, while basalt and gabbro are mafic (click here for more information on mafic and felsic). In the same respect, granite is the cooled (and exposed) magma chamber for extrusive rhyolite.
What is the difference between mafic and felsic igneous rocks?
Chemically, mafic rocks are enriched in iron, magnesium and calcium and typically dark in color. In contrast, the felsic rocks are typically light in color and enriched in aluminium and silicon along with potassium and sodium. The mafic rocks also typically have a higher density than felsic rocks.
Where are felsic igneous rocks found?
Felsic Igneous Rocks At the shallowest depths, dikes, sills, plugs and stocks are found in eroded volcanic centers, providing a record of sub-volcanic plumbing systems.