PMA Review-Rock Cycle

PMA 2 Review-Rock Cycle

​

Multiple Choice

The Geological Society of the United Kingdom describes igneous rock as “formed from molten rock called magma. They are mostly crystalline (made up of interlocking crystals) and usually very hard to break.”

According to this description, why would some designers use igneous rock, such as granite, as a building material?

• Igneous rock resists weathering and erosion, so is very durable

• Igneous rock weathers easily, so it changes quickly into unique shapes

• Since igneous rock is formed from magma, it must always stay warm.

Multiple Choice

Weathering is the process of rocks being broken down. Physical weathering breaks the same rock into smaller pieces. Chemical weathering breaks a rock down into a new substance (such as when acidic water dissolves limestone in Florida).

Which of these would go in the middle of the Venn diagram to the left?

• Require a chemical reaction

• Participate in the rock cycle by breaking up large rocks

• Occur when water in rock’s cracks freezes and expands

Multiple Choice

One wise science teacher likes to say, “Rocks are in a continual process of being broken, moved, and built. Weathering breaks rocks down, erosion moves the pieces (sediment), and deposition builds rocks back up.”

Which of these processes probably caused the cracks in the rock shown here?

• Deposition - building the rock

• Weathering - breaking the rock down

• Erosion - moving sediment to a new place

Multiple Choice

According to the diagram on the right, which of these statements is TRUE?

• Igneous and metamorphic rock can both melt into magma, but magma always becomes metamorphic rock when it cools.

• Igneous and metamorphic rock can both melt into magma, but magma always cools into igneous rock.

• Rocks always follow a one-way path through the rock cycle.

Multiple Choice

Dr Miller is a geologist. He says “Plate tectonics are the engine that drives the rock cycle.” What does he mean?

• When tectonic plate separate (diverge) magma comes to the Earth’s surface as igneous rock, which can then weather into sediment. The rock cycle then continues.

• All weathering, erosion, and deposition are all done by tectonic plates.

• There is an actual engine in the center of the Earth that is started by the plates.

Multiple Choice

According to the diagram on the left, which type of rock can contribute to forming a mountain?

• Igneous (when magma rises and cools)

• Metamorphic (when it’s pushed up or ‘uplifted)

• All three types of rock can contribute to mountain formation

Multiple Choice

Paleontologists have discovered fish fossils in what is now a desert in Western Egypt. What is the most likely explanation for this discovery?

• Fish used to swim in desert sand, but have changed over time and are now adapted to water.

• A tectonic plate moved the fish into the dessert.

• The land in Western Egypt used to be under an ocean, but natural process slowly changed the land over time.

Multiple Choice

When geologists removed a small column of earth, they found a layer of basalt above a layer of limestone. Why would they conclude that the basalt is younger than the limestone?

• The basalt layer is thinner, as it hasn’t had a chance to grow yet.

• Geologists are merely guessing about which rock layer is younger.

• New layers are formed on top of existing layers by sediment being eroded from other places and deposited in a new area

Multiple Choice

The geologic time scale allows us to think about time periods that are millions of years long. Why is this scale useful when thinking about the formation of the Earth?

• Geologists like to say really big numbers to show off.

• All geologic dates are estimates, so it’s best to use very large numbers.

• Compared to a human life, Earth changes slowly. Radioactive dating leads scientists to conclude that the earth is over 4 billion years old.