Writing an Argument About Geologic Time
Your Learning Task:
You will write an argument defending one of the claims from the “The most basic things I should
know after this unit” on your “Geologic Record Checklist.” You will support your claim using the
evidence you have collected in your Interactive Science Notebook, including your lab notes,
visuals (charts, maps, graphs), research, and any other useful information you have gathered.
Your Claims:
1. The Earth is 4.6 billion years old.
○ Note:​
You will need to offer​
3​
reasons this claim is correct. You may reword or
add to this claim to complete your thesis.
○ Example:
The Earth is 4.6 billion years old as evidenced in …. , …. , and ….
2. Earth is constantly changing, and the evidence we have for these changes and
Earth’s past are found in ​
fossils, rocks, and ice cores.
○ Note:​
You have your 3 supporting reasons (highlighted) included in this claim.
3. In general, older rocks are found in layers that are beneath younger rocks.
○ Note: ​
Again, you will need to add to your claim​
3​
​
convincing reasons.
○ Example:
According to evidence found in … , … , and … , older rocks are found in layers
that are beneath younger rocks.
4. All the Earth processes in the past still occur today (i.e. weathering, erosion, etc.).
● Note:​
You will need to remove the parenthesis here and use the processes
mentioned (weathering, erosion), with the addition of one more.
● Example:
All of the Earth processes in the past still occur today, including weathering,
erosion, and …
5. The geologic record is being added to as more data and evidence are found.
○ Note:​
Add your three supporting reasons. What is this evidence? What is this
data?
○ Example:
The geologic record is being added to as more data and evidence are found,
including … , … , and ...
Part 1: The Introduction
Writing a Thesis Statement:
Your thesis statement is based on your claim from “The most basic things I should know after this
unit” on your “Geologic Record Checklist.” See the section of this document entitled “Your
Claims” for suggestions.
Introductory Paragraph:
Once you have determined your thesis statement write a clear and interesting introductory
paragraph. Your introduction will include at least three sentences, and it will end with your
thesis statement. The purpose of an introduction is to interest and orient (give direction) to your
reader.
Part 2: The Body
Organizing Your Argument:
You will need to support your thesis in the body of your argument by offering supporting
evidence that you have collected and analyzed in your Interactive Science Notebook.
In your body, you will need ​
3 paragraphs​
that support your claim, one for each body
(group/type) of evidence ​
or​
one for each reason.
When we wrote our editorials we followed this sequence for constructing an argument:
CLAIM ------ REASON ------- EVIDENCE (EXAMPLE/SUPPORTING DETAILS)
We will use this sequence again for your scientific argument.
Writing a Topic Sentence:
Begin each paragraph in your body with a topic sentence. A topic sentence orients
(directs/guides) the reader about what you will discuss in each paragraph.
Part 3: The Conclusion
Conclude your argument with a short paragraph in which you leave your reader with some final
thoughts. Ask yourself this: What is the impression I want to leave on my reader? Also reiterate
(restate) your thesis with repeating it verbatim (word-for-word).