Earth History Investigation 3 Deposition

Two students are exploring a creek in their neighborhood. In one area, the creek has exposed a layer of shale. What kind of environment might have once existed here to create that rock layer? (Mark the one best answer.)

• A river

• A coral reef

• A swamp

• A sandy beach

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NGSS.MS-ESS2-2

Continuing along the creek, they find some pieces of white sandy rock in the creek. They drip hydrochloric acid on that rock. The rock does not fizz. What processes likely formed the rocks in the creek?

• There is no process, rocks just appear

• The processes that formed the rocks are volcanoes

• The process that formed the rocks are chemical reactions and melting

• The processes that formed the rocks are deposition, cementation, and erosion because there was no chemical reaction (fizz)

Tags

NGSS.MS-ESS2-2

Which statement best describes the principle of uniformitarianism? (Mark the one best answer.)

• Deposition occurs faster today than it did in ancient environments.

• Rocks form by the same processes today as in the past

• Weathering and erosion can be fast or slow, depending on the type of rock.

• Earth’s geological features were formed by a few catastrophic events.

Why is uniformitarianism an important principle to consider when making inferences about how Earth’s geology has changed over millions of years? (be sure to restate and answer the question!)

• Uniformitarianism is about organisms wearing a uniform

• Uniformitarianism is about everything on the planet being exactly the same.

• Uniformitarianism is when someone clones all organisms to make them identical to all other organisms on the planet.

• Uniformitarianism says that the processes that shape Earth are the same throughout time. That means if we observe a process shaping Earth today, we can assume the same process shaped Earth in the past and will shape Earth in the future all over the planet and even on other planets.

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NGSS.MS-ESS2-2

NGSS.MS-ESS2-3

NGSS.MS-ESS3-1

Do scientists think that new rocks are still forming today? How does uniformitarianism help scientists answer the first question?

• Today we see evidence of rock formation like cementation in mudstone, sediments layering, and volcanoes erupting, but most rock formation is impossible for us to observe (see how rocks actually form) directly. However, if rocks were not still forming today, the Earth's surface would probably be smooth and level due to constant weathering, with thick layers of sediments. We know that is not the case. Uniformitarianism helps explain this because it suggests that the processes that we see today are the same as in the past and will be in the future.

• We cannot see rock formations and there for we have no idea how rocks actually form.

• Weathering does not affect rock size at all and there for there is no need for any new rocks to ever form. Whatever is on the planet millions of years ago is still here and has not changed over time.

• Uniformitarianism does not explain how new rocks form because it is about how things are all the same.

Some students wanted to investigate how five different sediments settled in a basin of water. They started with the basin flat on the table and added new sediments each day for three days. On the fourth day, they gently tilted the basin before adding the sediments for the last few days. (Note: The layer shaded gray represents the water.)

Which drawing best represents the basin layers and water at the end of their investigation? (Mark the one best answer.)

• A

• B

• C

• D

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NGSS.MS-ESS2-1

How does this investigation apply to the formation of rock layers in the real world?

• Layers gradually tilt until they become horizontal, larger sediments are found in the bottom layers than in the top.

• The wind will blow the sediment into different positions.

• An entire basin can become tilted, layers always form horizontally, and newer layers form on top of older layers.

• Older layers will always form on top of new layers.

Tags

NGSS.MS-ESS1-4

NGSS.MS-ESS2-2

Examine the rock layers below. Label the oldest layers.

• Sandstone

• Shelly limestone

• Shale

Tags

NGSS.MS-ESS1-4

Examine the rock layers below. Label the youngest layers.

• Sandstone

• Shelly limestone

• Shale

Tags

NGSS.MS-ESS1-4

A theory that says geologic processes observed in the past are the same as those observed today. (The processes that are shaping Earth today, are the same processes that shaped Earth in the past and will shape Earth in the future.)

• Cementation

• Compaction

• Uniformitarianism

• Precipitate