LSAT 21, Section 4, RC Passage 3, Oil’s Origins

RC Passage 3 Explanation

Paragraph Summaries

1. Most petroleum geologists think oil comes from compressed organic matter.
2. Abiogenic theory says instead that oil comes from pressures within the earth’s mantle.
3. Some claim that hydrocarbons couldn’t survive the high heat of the mantle. Abiogenic advocates claim that high pressures allow hydrocarbons to survive, and that unoxidized carbon can survive in the mantle.
4. At least one Swedish company believes in Abiogenisis, and they are drilling for oil to test the theory.

Analysis

This passage seems like a neutral description of abiogenic theory. The author never says whether the theory is right or wrong. But the author appears to favor the theory, he allows abiogenic theory to make a rebuttal in the third paragraph. Successful rebuttals greatly strengthen a position.

The author doesn’t say abiogenic theory is correct. But he does think abiogenic theory could be correct. See lines 34-37.

The point of the passage is to show that abiogenic theory is a possible alternative to the mainstream theory.

You don’t need to know all the details. The second paragraph is hard to keep track of, for example. Just know that you must look back there when a question asks how abiogenic theory claims that oil is produced.

It’s important to know that the author thinks abiogenic theory could be correct. See lines 34-37.

You should also have a rough idea what each theory says.

Biogenic: Oil comes from organic matter that gets buried.

Abiogenic: Oil comes from heat and pressure deep within the Earth’s mantle.