Grade 7 Unit 6 History of the Earth

Lesson Review and Mini Assessment

Mrs. Danvers

Examples of the physical evidence that supports scientific theories that Earth has evolved over geologic time due to natural processes.

• ​On an ice-covered island in the Arctic, scientists discovered fossils of deciduous trees, such as oak, birch, sycamore, and walnut. Scientists determined that these fossils were formed about 50 million years ago.

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Measure the Earth's Age

​We measure the age of the earth by resting the rate of the decay of specific elements in rock samples.

Superposition

​We measure the age of the earth by resting the rate of the decay of specific elements in rock samples.

Multiple Choice

Which of the following is the best way to measure the age of the Earth?

• Examine rocks collected in my backyard

• Analyze maps of all known fossil sites in the United States

• Test the rate of decay of specific elements in rock samples

• Explore leaves embedded in ash from recent volcanic eruptions

Multiple Choice

Many inland areas around Florida contain extinct marine fossils. Which of the following statements best describes how this might have occurred?

• Predatory birds carried prey to their inland nests and discarded the bones on the ground.

• Some ancient marine organisms had the ability to walk on land and likely migrated inland

• Ocean levels were once much higher than they are today so inland areas were under water.

• Strong winds carried marine organisms inland where they were buried and fossilized under layers of sediment.

Multiple Choice

Which of the following statements is most accurate as it relates to the Law of Superposition?

• The Law of Superposition is an explanation relating to the sequence of disturbed rock layers

• The Law of Superposition is an observable fact relating to the sequence of undisturbed rock layers.

• The Law of Superposition is a study of past events preserved in disturbed rock layers and their exceptions. 

• The Law of Superposition is a theory that may be replaced by an improved theory if new discoveries are made relating to the sequence of undisturbed rock layers..

Multiple Choice

Which of the following is an example of absolute dating?

• A sedimentary rock layer is between 10,000 and 10,500 years old.

   

• A sedimentary rock layer is younger than the existing layer below it.

• A sedimentary rock layer is 20,000 years old because it is a scientific law.

• A sedimentary rock layer contains fish fossils, but the layers above and below it do not contain any fossils.