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hi! pl. explain the CR

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by ansumania » Fri Apr 16, 2010 4:01 am
Determining the authenticity of purported pre-Columbian artifacts is never easy. Carbon-14 dating of these artifacts is often impossible due to contamination by radioactive palladium (which occurs naturally in the soils of Central and South America). However, historians and anthropologists have evolved two reliable criteria, which, utilized in combination, have proven effective for dating these artifacts. First, because authentic pre-Columbian artifacts characteristically occur in a coarse, granular matrix that is shifted by major earthquakes, they often exhibit the unique scratch patterns known as gridding. In addition, true pre-Columbian artifacts show a darkening in surface color that is caused by centuries of exposure to the minute amounts of magnesium in the soil of the Americas.

The criteria above would be LEAST useful in judging the authenticity of which of the following?

(A) An ax head of black obsidian, unearthed from a kitchen midden
(B) A pottery bowl with a red ocher design, found in the ruins of a temple
(C) A set of gold ear weights, ornamented with jasper pendants
(D) A black feather cape from a king's burial vault
(E) A multicolored woven sash found near the gravesite of a slave


regards,

Ansumania
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Source: — Critical Reasoning |

by neoreaves » Fri Apr 16, 2010 4:55 am
I will go with D


we need to find an artifact that can NOT be judged by gridding and darkening color ....

gridding is caused by earth shifting ....

D - the black feather was inside a vault so it wont show gridding as it was already protected by the vault
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by vivek1110 » Fri Apr 16, 2010 5:13 am
Wow this one's a thinker, what's the source?

I thought it's C, I have no clue why though. What's the OA?
Is caught between a rock and a hard place!
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by ironstar37 » Fri Apr 16, 2010 9:18 am
IMO (D): We are looking for an artifact which would be unaffected by gridding AND darkening in surface colour.

(A) (B) and (C) are tangible objects which are affected by gridding.

(D) Correct: Cape material would be unaffected by gridding. Further, the colour is already dark (black) and thus, it would be difficult to show a further darkening in surface colour.

(E) Would be unaffected by gridding, however, could see the darkening in surface colour over time.
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