Clay ComponentAncient pottery sample AAncient pottery sample BModern clay depositKaolinite454215Montmorillonite121435Temper fragments86not detectedMic...
GMAT Information and Ideas : (Ideas) Questions
| Clay Component | Ancient pottery sample A | Ancient pottery sample B | Modern clay deposit |
|---|---|---|---|
| Kaolinite | 45 | 42 | 15 |
| Montmorillonite | 12 | 14 | 35 |
| Temper fragments | 8 | 6 | not detected |
| Mica inclusions | 23 | 19 | not detected |
| Iron oxides | 18 | 22 | 28 |
Archaeologist Dr. Sarah Chen and her research team used X-ray diffraction analysis to examine the mineral composition of pottery fragments discovered at an ancient settlement site. They compared samples from two pottery shards with clay deposits found near the excavation area to determine whether the ceramics were produced locally or imported from elsewhere. By analyzing the relative concentrations of different clay components in the ancient pottery versus the local clay deposits, the team concluded that the pottery was likely manufactured at a distant location and transported to the settlement.
Which choice best describes data from the table that support the team's conclusion?
Kaolinite and iron oxides were detected in both the ancient pottery samples and in the modern clay deposit.
Temper fragments and mica inclusions were detected in both pottery samples but not in the local clay deposit.
Montmorillonite and iron oxides were detected in both pottery sample B and in the local clay deposit.
Kaolinite and mica inclusions were detected in pottery sample A but showed different concentrations in sample B.
Step 1: Decode and Map the Passage
Part A: Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Archaeologist Dr. Sarah Chen and her research team used X-ray diffraction analysis to examine the mineral composition of pottery fragments discovered at an ancient settlement site." |
|
| "They compared samples from two pottery shards with clay deposits found near the excavation area to determine whether the ceramics were produced locally or imported from elsewhere." |
|
| "By analyzing the relative concentrations of different clay components in the ancient pottery versus the local clay deposits, the team concluded that the pottery was likely manufactured at a distant location and transported to the settlement." |
|
Part B: Provide Passage Architecture & Core Elements
Main Point: Dr. Chen's team determined that ancient pottery found at a settlement site was manufactured elsewhere and imported, based on mineral composition analysis comparing the pottery to local clay deposits.
Argument Flow: The passage establishes a straightforward research scenario where archaeologists use scientific analysis to solve a sourcing question. They compare ancient pottery composition with local clay to test whether the pottery was made locally, and their analysis led them to conclude it was imported from a distant location.
Step 2: Interpret the Question Precisely
What's being asked? We need to identify which data from the table supports the team's conclusion that the pottery was made elsewhere and transported to the settlement.
What type of answer do we need? Specific evidence from the mineral composition data that would indicate non-local origin.
Any limiting keywords? None specified.
Step 3: Prethink the Answer
- If pottery was made locally, we'd expect its mineral composition to closely match the local clay deposits
- Evidence for non-local origin would be components present in ancient pottery but absent from local clay, or dramatically different concentrations of shared components
- The right answer should point to components found in the ancient pottery that are not detected at all in the local clay deposits
Kaolinite and iron oxides were detected in both the ancient pottery samples and in the modern clay deposit.
✗ Incorrect
- Points to shared components present in both pottery and local clay
- This similarity would actually suggest local production, not distant manufacturing
Temper fragments and mica inclusions were detected in both pottery samples but not in the local clay deposit.
✓ Correct
- Identifies temper fragments and mica inclusions present in both pottery samples but completely absent in local clay
- This clear compositional difference strongly supports non-local origin
Montmorillonite and iron oxides were detected in both pottery sample B and in the local clay deposit.
✗ Incorrect
- Points to shared components between pottery B and local clay
- Shared components suggest similarity rather than supporting the distant origin conclusion
Kaolinite and mica inclusions were detected in pottery sample A but showed different concentrations in sample B.
✗ Incorrect
- Compares the two pottery samples to each other rather than comparing pottery to local clay
- Doesn't address the key question of local vs. distant origin