Metamorphic Rock Notes

So during metamorphic rock processes, the mineral grains can become flattened, under pressure, and they can exchange atoms with other minerals undergoing chemical reactions and creating new memories. There are two main ways that metamorphosis can happen. The first is contact metamorphosis in which magma moves into preexisting rock and The Rock that comes in contact with the heat undergoes chemical changes and creates new forms of minerals and rocks. This is considered small-scale metamorphosis because it only changes a small amount of rock at a time. Notice in this picture, the layers of rock represent sedimentary rock. The intrusion here at one point would have been lava that cut across the sedimentary rock. 

Some of the sedimentary rock that it touched became hot enough to change it, but not to melt it. So The Rock that was chemically changed by the heat becomes metamorphic rock on either side of this intrusion. The magma would have solidified to form igneous rock, and again The Rock in the background is sedimentary rock. So only a small amount of metamorphic rock is created at a time. Regional metamorphism is large-scale metamorphosis and it happens because of deformation during mountain building. So if you'll remember mountains on land are built when two tectonic plates collide. So the friction and pressure of those colliding plates creates lots of heat and pressure, which can change large amounts of rock at a time. So we call this large-scale metamorphosis. So another graphic to represent the two regional metamorphosis and means tectonic plates are pressing in on rock, squeezing it together. 

You have some folding of this rock. It's bending the layers deforming all those layers and changing lots of metamorphic rock at a time. And this picture contact metamorphosis and means only The Rock that's in contact with the hot magma has been changed to metamorphic rock. Once the metamorphic rock is created, there are two classifications of metamorphic rock. If the metamorphic rock has any signs of layers or bands, it is known as foliated metamorphic rock. So stripes, parallel layers, all are considered foliated metamorphic rocks. If The Rock doesn't show any signs of layering or banding, it is known as a nonfoliated metamorphic rock. Let's talk a little more about coal because there are metamorphic forms of coal and sedimentary forms of coal. 

There are four stages in coal formation. The first stage is peat, which is partially decayed plant material. Remember, coal is formed from swamp plants that live millions of years ago. So the first stage is when the plant dies and is just partially decayed. If the peat is put under pressure for a long period of time, it can be compacted together to make a sedimentary rock called lignite. This is a soft, low-grade coal, and it is light and color. So we can burn this and get energy from the coal, but low grade means that you don't get a lot of energy from this type of coal, and it releases lots of air pollution. Sage two is by two minus coal, we mentioned by two minutes coal and the sedimentary rock notes, so by two minutes coal is the sage after lignite. And as it's going through the stages, it's going to be more energy efficient, meaning it releases more energy and less pollution when burned and it becomes darker in color and more dense. 

The fourth stage is finally the metamorphic stage with which is anthracite coal. So it forms after by two miss Cole is left under extreme heat and pressure for a long time. So this is the darkest form of coal. It becomes shiny at this point. It's most dense and most energy efficient. On the next page of your metamorphic rock notes, you'll notice a chart with specific metamorphic rock names. So we're going to look at some pictures and talk about the different kinds of metamorphic rock. Notice you have a problem on your chart entitled parent rock. Parent rock refers to what type of rock or which specific rock, the metamorphic rock was before it was changed under heat and pressure. So slate is a foliated metamorphic rock. Notice it's mostly the same color, but if you could look at it from the side, you see some layering here. 

You may have seen slate stepping stones or even slate roofing shingles, and it's useful for that because it separates easily into sheets because of that foliation. Slates, parent rock is shale. So shale is a sedimentary rock when it's left under heat and pressure. It changes to slate. And the other notes category you can list some uses for slate. We mentioned roofing shingles and stepping stones. It can also be used for chalkboards and as an electric insulator. This picture shows a slate roof. Nice is a foliated metamorphic rock. Notice all the stripes in the side, it contains lots of quartz and feldspar and alternating light and dark bands. Nice forms from granite, which is an igneous rock. So you can see from the picture of the granite after it undergoes metamorphosis. 

This is it has flattened out minerals. Nice can be used as building stones, and it can come in lots of different colors, just like quartz and feldspar come in different colors. The combination of those can also come in different colors. Marble is a nonfoliated, metamorphic rock, notice it has no signs of layers, bands or stripes. It is formed from limestone, which is a sedimentary rock. In marvel has many uses, it can be ground up to use as a filler in paper toothpaste paint and plastics. You can also be carved used for decorative items, or use for building stones. Here's a picture of large deposits of marble that have been mined in marble, Colorado. 

There's a tombstone carved from marble. This is a solid sheet of marble that has mineral deposits that made it look like a painting. Another kind of metamorphic rock is schist, schist is also foliated, you can see the flattened-out bands in the shift. And if you can look at it from the side, it looks layered from the side. It also forms from granite. So granite can be the parent rock of nice or just. She just has lots of Micah's top corn blend and graphite mixed together. The mica are the shiny little specks that make The Rock look kind of glittery, and again, those have been flattened out. So you can see flat specks in here from the foliation. Some shifts can be used for building stones. 

Quartzite is a nonfoliated metamorphic rock. It can come in different shades, but it has no signs of layers or bands. It forms from a sedimentary rock called sandstone. Greenstone is another example you don't have on your sheet, but this is a common metamorphic rock that forms from basalt. The salt is another type of igneous rock. And anthracite coal, we've already mentioned, is a nonfoliated metamorphic rock, and of course, its parent rock is by two municipal, and it is useful because it can be burned as fuel.