Astronomers investigated the Arabia Terra region of Mars because it appears to contain irregularly shaped craters that may have been...
GMAT Information and Ideas : (Ideas) Questions
Astronomers investigated the Arabia Terra region of Mars because it appears to contain irregularly shaped craters that may have been caused by massive volcanic explosions. In their investigations of Arabia Terra, the researchers found remnants of ash deposits in an amount and thickness that would result from a massive volcanic eruption. However, erosion and past resurfacing events could have modified the surface of the planet. Therefore, ______
Which choice most logically completes the text?
the current makeup of the Arabia Terra region might not accurately reflect the volcanic activity of Mars's past.
eruptions from Mars's volcanoes were likely not as massive as astronomers previously believed.
ash was most likely expelled from multiple different volcanoes on Mars's surface.
the craters found in the Arabia Terra region were necessarily created by events other than volcanic eruptions.
Step 1: Decode and Map the Passage
Part A: Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| 'Astronomers investigated the Arabia Terra region of Mars because it appears to contain irregularly shaped craters that may have been caused by massive volcanic explosions.' |
|
| 'In their investigations of Arabia Terra, the researchers found remnants of ash deposits in an amount and thickness that would result from a massive volcanic eruption.' |
|
| 'However, erosion and past resurfacing events could have modified the surface of the planet.' |
|
| 'Therefore, ______' |
|
Part B: Provide Passage Architecture & Core Elements
Main Point: Astronomers found evidence supporting volcanic activity on Mars, but surface modifications over time complicate direct interpretation of current observations.
Argument Flow: The passage starts with astronomers investigating a region that might show volcanic activity. They find supporting evidence (ash deposits), but then introduces the crucial caveat that the surface could have been modified over time. This sets up a logical conclusion about the reliability of current surface features as indicators of past volcanic activity.
Step 2: Interpret the Question Precisely
This is a fill-in-the-blank question asking us to choose the best logical connector. The answer must create the right relationship between what comes before and after the blank.
Step 3: Prethink the Answer
- The logical flow is: We found evidence of volcanic activity, BUT the surface could have been changed over time by erosion and resurfacing
- Therefore, what we see now might not accurately represent what happened in the past
- The correct answer should express that the current state of the region may not accurately reflect the volcanic history due to the surface modifications mentioned
the current makeup of the Arabia Terra region might not accurately reflect the volcanic activity of Mars's past.
✓ Correct
- This directly follows the logical flow: evidence suggests volcanic activity, but surface modifications mean current appearance might not reflect past reality
- Perfectly captures the uncertainty created by erosion and resurfacing
eruptions from Mars's volcanoes were likely not as massive as astronomers previously believed.
✗ Incorrect
- Claims eruptions were 'not as massive as previously believed' but passage doesn't establish what astronomers previously believed about eruption size
- Misses the main point about surface reliability
ash was most likely expelled from multiple different volcanoes on Mars's surface.
✗ Incorrect
- Suggests multiple volcanoes were involved, but passage focuses on one region and doesn't provide evidence for multiple sources
- Completely ignores the surface modification concern
the craters found in the Arabia Terra region were necessarily created by events other than volcanic eruptions.
✗ Incorrect
- States craters were 'necessarily created by events other than volcanic eruptions,' which directly contradicts the ash deposit evidence
- The word 'necessarily' is too strong and opposite to what the evidence suggests