Energy
Name the two sources of energy that drive the rock cycle.
The sun and Earth's internal heat and pressure
Describe how igneous rocks are formed.
Rock that is buried deep within the Earth heats up so much that eventually it melts. This melted rock flows as magma and sometimes it bursts onto Earth's surface when a volcano erupts. This magma is now called lava as it flows down the side of the volcano. The lava cools quickly and becomes hard rock. This is igneous rock. Igneous rocks are usually dark colored with trapped gas bubbles visible. They have a course texture. An example of an igneous rock is basalt.
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Physical weathering and chemical weathering
How does energy drive weathering?
The sun control's Earth's temperature - heating and cooling - which causes physical weathering. The sun's energy also drives the water cycle which results in precipitation, including acid rain, causing chemical weathering.
Describe how metamorphic rocks are formed.
Metamorphic rocks are formed deep underground by heat and pressure. They are are not melted but squished and folded, which sometimes results in visible ribbon-like layers. They eventually come to the surface through uplift. An example of a metamorphic rock is slate.
Describe how one rock becomes another kind of rock.
A rock of any type - igneous, metamorphic, or sedimentary - can be weathered and eroded and carried to a new location where it can be affected by heat, pressure, etc. Over a long period of time, this heat or pressure will transform the rock into a totally new type of rock. For example, sedimentary rock in a canyon can break down from physical weathering caused by freezing temperatures. The particles that break off can be eroded by water that carries it way down a stream. Eventually the rock particle rests in the ground on the banks of the stream. Over time it is buried deeper and deeper underground. Eventually it reaches the Earth's mantle and is heated into flowing magma. The magma flows toward a volcano, and at some point the volcano erupts. The magma bursts out and becomes lava as it runs down the sides of the volcano and cools quickly. When the lava cools it becomes hard rock. This rock is an igneous rock and contains particles of the sedimentary rock from the canyon where we started.
Describe how below-freezing temperatures cause physical weathering.
How does energy create uplift?
Extremely hot temperatures in Earth's core create pressure that, over time, forces forces rock formations up through Earth's crust, forming mountains, hills, etc.
Describe how sedimentary rocks are formed.
Weathering and erosion break down rocks so that sediment is carried away. This sediment is deposited into layers and compacted be pressure so that eventually it cements together into a new sedimentary rock. Sedimentary rock often has visible layers and may contain fossils. Limestone is an example of a sedimentary rock.
How could rock form under water?
Sediment is carried by wind and water and could come to rest at the bottom of a body of water. Over time it could be layered and pressed down (sedimentation and cementation) to create sedimentary rock.
Describe how acid rain causes weathering.
Acid rain causes chemical weathering when the acid in rain changes the chemical composition of the rock. For example, acid can dissolve lime stone, resulting in chemical weathering.
How does energy drive metamorphic rock formation?
Heat and pressure deep within Earth transforms rocks of all kinds into metamorphic rocks. The heat does not melt the rock (that would be magma/lava/igneous rock), but folds and squishes the rock into more compact metamorphic rock.
Describe the differences between the command terms outline and describe.
Describe means to give a detailed account. When you describe, you include lots of information, specific details and examples. Outline means to give a brief account. When you outline, you might only cover the basic points.
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Describe how the two "agents" of erosion work.
How does energy drive erosion?
The sun's energy controls water and wind patterns on Earth. Water and wind cause erosion.
What physical characteristics do geologists observe in order to classify a rock?
Texture, color, hardness, layering
Do all rocks follow the same path in the rock cycle?
No, all rocks do not follow the same path. The rock cycle is not linear. Rocks can move all over the rock cycle.
For example, and igneous rock may be weathered down into sediment, carried by erosion to a stream bed, compacted and sedimented over time and become sedimentary rock.
However, that same igneous rock might be buried far within the earth, and over time compacted by heat and pressure and become a metamorphic rock.
How do weathering and erosion work together to shape Earth's surface?