Limestone is composed of calcium carbonate, which is water soluble it dissolves in water. Therefore, the limestone you find in a dry area will remain a rock a lot longer than limestone you find in a MOIST area. Regarding metamorphic rocks, there really aren't many of these on the Colorado Plateau..
So, good thing for you, we are really not going to cover this rock type in this Module. You will see a few igneous rocks in this Module You see granite intrusive igneous and basalt extrusive igneous. The granite you will see is high up in the La Sal Mountains and the basalt you will see sits as cap rocks on top of softer, underlying sediments.
A cap rock is a comparatively more resistant rock that protects the rocks beneath it from weathering and eroding. The key to understanding rock weathering is to realize that rocks weather at different rates and into different forms based on their chemical composition and based on what weathering processes dominate the area.
For WAY more information on rocks than you are required to know for this Module, visit the following links:. Jump to igneous Jump to metamorphic Jump to sedimentary. Weathering breaking down rock and erosion transporting rock material at or near the earth's surface breaks down rocks into small and smaller pieces.
These smaller pieces of rock such as sand, silt, or mud can be deposited as sediments that, after hardening, or lithifying, become sedimentary rocks. Extreme pressure from burial, increasing temperature at depth, and a lot of time, can alter any rock type to form a metamorphic rock.
If the newly formed metamorphic rock continues to heat, it can eventually melt and become molten magma. When the molten rock cools it forms an igneous rock. Metamorphic rocks can form from either sedimentary or igneous rocks. The sedimentary particles from which a sedimentary rock is formed can be derived from a metamorphic, an igneous, or another sedimentary rock.
All three rock types can be melted to form a magma. Thus, the cycle has continued over the ages, constantly forming new rocks, breaking those down in various ways, and forming still younger rocks. Rocks at the surface of the earth range in age from over three billion years old to a few hundred years old. Igneous rock can change into sedimentary rock or into metamorphic rock. Sedimentary rock can change into metamorphic rock or into igneous rock.
Metamorphic rock can change into igneous or sedimentary rock. Igneous rock forms when magma cools and makes crystals. Magma is a hot liquid made of melted minerals. The minerals can form crystals when they cool. Igneous rock can form underground, where the magma cools slowly.
Or, igneous rock can form above ground, where the magma cools quickly. Notice how many time "weathering" and "erosion" green arrows appear in the above diagram? When it pours out on Earth's surface, magma is called lava. Yes, the same liquid rock matter that you see coming out of volcanoes. Igneous rock that pours out onto the Earth's surface is called igneous extrusive , whereas igneous rock that cools beneath the surface is called igneous intrusive.
On Earth's surface, wind and water can break rock into pieces weathering! They can also carry rock pieces to another place erosion!. Usually, the rock pieces, called sediments, drop from the wind or water to make a layer. The layer can be buried under other layers of sediments.
After a long time the sediments can be cemented together to make sedimentary rock. In this way, igneous rock can become sedimentary rock. All rock can be heated. But where does the heat come from? Inside Earth there is heat from pressure push your hands together very hard and feel the heat. There is heat from friction rub your hands together and feel the heat. There is also heat from radioactive decay the process that gives us nuclear power plants that make electricity.
So, what does the heat do to the rock? It bakes the rock. Remember, all rocks are made up of mineral crystals, or pieces of other rocks made up of crystals.
Baked rock does not melt, but it does change. It forms crystals. If it has crystals already, it forms larger crystals. Because this rock changes, it is called metamorphic. Remember that a caterpillar changes to become a butterfly. That change is called metamorphosis. Metamorphosis can occur in rock when they are heated to to degrees Celsius. When Earth's tectonic plates move around, they produce heat. When they collide, they build mountains and metamorphose the rock.
The rock cycle continues. Mountains made of metamorphic rocks can be broken up and washed away by streams. New sediments from these mountains can make new sedimentary rock. The rock cycle never stops. Igneous Rocks : Igneous rocks are a type of rock formed from extremely hot 2, degrees F molten masses known as magma. Generally, magma lies about 90 miles below the surface. In certain places, such as Yellowstone National Park, the magma is as close as 40 miles below the surface.
On average, every feet you dig down into the earth, the temperature will increase about 1. Sometimes magma forces its way up to the surface through a vent such as a volcano and spills onto the surface. This happened near Flagstaff, Arizona at Sunset Crater less than 1, years ago. Once magma comes out onto the surface of the earth it is called lava, and it cools rapidly at the surface.
Extrusive igneous rocks can be distinguished by their small crystal sizes. On Earth's surface, wind and water can break rock into pieces. They can also carry rock pieces to another place.
Usually, the rock pieces, called sediments, drop from the wind or water to make a layer. The layer can be buried under other layers of sediments. After a long time the sediments can be cemented together to make sedimentary rock.
In this way, igneous rock can become sedimentary rock. All rock can be heated. But where does the heat come from? Inside Earth there is heat from pressure push your hands together very hard and feel the heat.
There is heat from friction rub your hands together and feel the heat. There is also heat from radioactive decay the process that gives us nuclear power plants that make electricity. So, what does the heat do to the rock? It bakes the rock. Baked rock does not melt, but it does change. What is an evaporite and how is it formed? How are sedimentary rocks different from igneous and metamorphic rocks?
Why do sedimentary rocks have layers? What happens when limestone comes in contact with an acid? Why are sedimentary rocks the only rock type to contain fossils? Why are sedimentary rocks stratified?
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