Text 1The Cretaceous-Paleogene (K-Pg) mass extinction event is usually attributed solely to an asteroid impact near Chicxulub, Mexico. Some scientists...
GMAT Craft and Structure : (Structure) Questions
Text 1
The Cretaceous-Paleogene (K-Pg) mass extinction event is usually attributed solely to an asteroid impact near Chicxulub, Mexico. Some scientists argue that volcanic activity was the true cause, as the K-Pg event occurred relatively early in a long period of eruption of the Deccan Traps range that initially produced huge amounts of climate-altering gases. These dissenters note that other mass extinctions have coincided with large volcanic eruptions, while only the K-Pg event lines up with an asteroid strike.
Text 2
In a 2020 study, Pincelli Hull and her colleagues analyzed ocean core samples and modeled climate changes around the K-Pg event. The team concluded that Deccan Traps gases did affect global conditions prior to the event, but that the climate returned to normal well before the extinctions began—extinctions that instead closely align with the Chicxulub impact.
Based on the texts, how would Hull's team (Text 2) most likely respond to the argument in the underlined portion of Text 1?
By agreeing that the Chicxulub impact changed the climate and that the Deccan Traps eruption caused the K-Pg event
By declaring that the changes in climate caused by the Deccan Traps eruption weren't the main cause of the K-Pg event
By questioning why those scientists assume that the Chicxulub impact caused the Deccan Traps eruption
By asserting that the Deccan Traps eruption had a more significant effect on global conditions than those scientists claim
Step 1: Decode and Map the Passage
Part A: Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "The Cretaceous-Paleogene (K-Pg) mass extinction event is usually attributed solely to an asteroid impact near Chicxulub, Mexico." |
|
| "Some scientists argue that volcanic activity was the true cause, as the K-Pg event occurred relatively early in a long period of eruption of the Deccan Traps range that initially produced huge amounts of climate-altering gases." |
|
| "These dissenters note that other mass extinctions have coincided with large volcanic eruptions, while only the K-Pg event lines up with an asteroid strike." |
|
| "In a 2020 study, Pincelli Hull and her colleagues analyzed ocean core samples and modeled climate changes around the K-Pg event." |
|
| "The team concluded that Deccan Traps gases did affect global conditions prior to the event, but that the climate returned to normal well before the extinctions began—extinctions that instead closely align with the Chicxulub impact." |
|
Part B: Provide Passage Architecture & Core Elements
Main Point: While there's debate about whether the K-Pg mass extinction was caused by an asteroid impact or volcanic activity, Hull's team's research supports the asteroid theory by showing that volcanic climate effects had ended before the extinctions actually began.
Argument Flow: The passage presents a scientific debate between the standard asteroid explanation and the volcanic alternative, then introduces new research by Hull's team that examined both factors and concluded the asteroid impact was indeed the primary cause.
Step 2: Interpret the Question Precisely
- What's being asked? The question asks how Hull's team would respond to the specific argument made by volcanic theory supporters about the pattern of mass extinctions and their causes.
- What type of answer do we need? [content]
- Any limiting keywords? [content]
Step 3: Prethink the Answer
- Hull's team found that Deccan Traps gases did initially affect global climate, but the climate had returned to normal well before the mass extinctions actually began
- The extinctions themselves lined up with the timing of the Chicxulub asteroid impact
- So Hull's team would acknowledge volcanic effects but maintain that they weren't the primary cause of the K-Pg extinctions
By agreeing that the Chicxulub impact changed the climate and that the Deccan Traps eruption caused the K-Pg event
✗ Incorrect
- Claims Hull's team would agree that both Chicxulub changed climate AND Deccan Traps caused the K-Pg event
- This contradicts Hull's conclusions
By declaring that the changes in climate caused by the Deccan Traps eruption weren't the main cause of the K-Pg event
✓ Correct
- Hull's team would say the Deccan Traps climate changes weren't the main cause
- This perfectly matches their findings that volcanic gases affected climate initially, but climate normalized before extinctions began
By questioning why those scientists assume that the Chicxulub impact caused the Deccan Traps eruption
✗ Incorrect
- Suggests Hull's team would question assumptions about causal relationships
- Hull's research doesn't address any causal relationship between the asteroid and volcanic activity
By asserting that the Deccan Traps eruption had a more significant effect on global conditions than those scientists claim
✗ Incorrect
- Claims Hull's team would say Deccan Traps had MORE significant effects than claimed
- This is backwards - Hull's team found the volcanic effects were less significant