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Lesson 6 Classwork | Absolute Dating and Fossil Record

Last updated almost 5 years ago
27 questions

Lesson 6 Classwork | Absolute Dating and Fossil Record


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A fossil was discovered that originally contained 200 grams of Carbon-14 now contains only 25 grams of Carbon-14. Approximately how many years ago was this sample part of a living tree? What geological time period was this fossil from?

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A sample of igneous rock has only 6.25 grams remaining out of an initial 400 grams of Potassium-40. How many half-lives has this rock undergone and how old is it?

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If 12.5 % of the original Potassium-40 remains in the sedimentary rock layer of marine origin, approximately how old is the rock layer?

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Would this Potassium-40 be very helpful in dating fossils of the Mastodont? (ESRT 8-9) Explain your reasoning.

Absolute Dating


What species did the fossil come from and when did it die? Records indicate that the species from which the fossil was formed was determined by examining the fossil bone structure, but due to a lack of technology, the fossil was never dated to ensure that its age matched the time period in which the species existed. Thanks to technological advances in radiometric dating, you can now determine the age of your fossil.
Task:
Geologist have discovered an unknown fossil in a layer of bedrock. The fossil is very important to scientists trying to reconstruct a part of Earth’s history and they would like to find more fossils like it. We have been asked to figure out whether this fossil can be found in New York State in order to help scientists narrow down their search.

Product: You will organize your data about the fossil with the aid of a variety of questions. Based on the data provided and your Earth Science Reference Table, write a scientific explanation using evidence determining if your fossil could have existed in New York State.
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If 25 % of the original radioactive isotope Q remains in a sample of your fossil, approximately how old is the fossil?

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Does the age you determined support the claim about what species your fossil came from? Be sure to explain your thinking.

Based on the age of the fossil, could it have been found in New York State? In order to have been found in New York State, the fossil has to have been formed before the rock layer was formed. You will need to use ESRT 3 to help you answer this section. Refer to the slides from lesson 6 to help complete this.
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Did bedrock in New York State form during this time period?

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What type of bedrock formed during this period?

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What is the only type of rock that can contain fossils (Use the internet to help find this answer)? This answer will help support you later in the final product.

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What city could you find this fossil in?

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Circle the area in New York state where you could find this fossil in the map below.

Final Response


Bring all the evidence together: Do you think this fossil could be found in New York State?

Explain why or why not you would expect to find the fossil in New York State. You should write at least one paragraph with evidence and reasoning to support your claim. Remember evidence can come from data or your observations. Make sure that you answer the following to help support your claim.
  • Name and age of fossil
  • Type of rocks fossils form in
  • If the age of the fossil correlates to a time period of bedrock in New York State
  • Age and type of bedrock that the fossil would be found in in New York State
  • What city or cities the fossil could be found in.
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Evidence

What are the relevant science observations or data that address the research question?

The evidence is …..

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Claim


What claim can be made based on the evidence?
Does the evidence support your claim?

The claim is …...

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Science Concepts


What scientific concepts are connected to the evidence and help explain the claim?

The science concepts that support the claim are …..

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Scientific Reasoning


How do the evidence and scientific concepts link to support the claim?

Because of (evidence) and (science concepts), then (claim)

Write your scientific reasoning here

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Construct a Scientific Explanation


Using the steps below and the information in the boxes you have completed, write a scientific explanation.
Scientific Explanation = Claim + Evidence + Scientific Reasoning
  1. State your claim
  2. Explain the evidence that supports your claim
  3. Explain the science concepts that support the evidence
  4. Explain the scientific reasoning that links the evidence and science concepts to the claim