Earth's surface consists of rigid plates that are

Question

Earthâ€™s surface consists of rigid plates that are constantly shifting and 
jostling one another. Plate movements are the surface expressions of motions in the mantleâ€”the thick shell of rock that lies between Earthâ€™s crust and its metallic core. Although the hot rock of the mantle is a solid, under the tremendous pressure of the crust and overlying rock of the mantle, it flows like a viscous liquid. The mantleâ€™s motions, analogous to those in a pot of boiling water, cool the mantle by carrying hot material to the surface and returning cooler material to the depths. When the edge of one plate bends under another and its cooler material is consumed in the mantle, volcanic activity occurs as molten lava rises from the downgoing plate and erupts through the overlying one. 
 Most volcanoes occur at plate boundaries. However, certain â€œmisplacedâ€

praveen_rao7 · Answer

DBBA ?

HongHu · Answer

DBEE

The third one is a little tricky, B seems quite close but I think E is better.

DLMD · Answer

Agree with the first three.

why it's E not A for the last question?

HongHu · Answer

Established plume means it's not "untapped" any more, I think.

prep_gmat · Answer

DBEE

For the 3rd, nothing in the passage suggests that the track of the plume was used to identify that the plates actually moved.

I thought that the second question with its reference to 'over a period of time' and then 'age' in the correct answer choice was a bit trickier than the rest.

chunjuwu · Answer

Hello, the OA is D,B,E,E

In the second question, why not A? 

How to infer ?

chunjuwu · Answer

could anybody tell me, please. :oops:

praveen_rao7 · Answer

chunjuwu, 
I am by no means an authority is RC, but here is my 2 cents.
only reference to Hawaiian islands we have in the passage is 
"The natural history of the Hawaiian island chain clearly shows the movement of the Pacific plate over a fixed plume".

in other words, the Author is using Hawaiian islands to explain a particular phenomenon. No where he mentions that this type of activity doesn't occur else where in the world. Hence choice A is wrong

Hope this helps

praveen_rao7 · Answer

chunjuwu I got your message, here is what I feel about Q 23

Q23 states 
It can be inferred from the passage that a chain of volcanoes created by a mantle plume would most likely be characterized by 

A. a curved outline 
B. constituent volcanoes that differ from each other in age 


A is indeed very tempting. But it is out of context. Passage says

"Because the source of a hot spot remains fixed while a surface plate moves over it, over a long period of time an active plume creates a chain of volcanoes or volcanic islands, a track marking the position of the plume relative to the moving plate."
 earlier in the passage it also states

"When the edge of one plate bends under another and its cooler material is consumed in the mantle, volcanic activity occurs as molten lava rises from the downgoing plate and erupts through the overlying one."


that means here emphasis is on the fact that hot spot remains fixed and plates move over it. When the hot spot hits the edges of the plates lava comes out. That means there is a time gap in between volcanos. Hence choice B

Even though the passage states "a track marking the position of the plume relative to the moving plate" it doesn't necessarily mean it is a curved outline because we don't really know how the plates move.

Rupstar · Answer

I think the first questions answer is D

Rupstar · Answer

Second one is B

Rupstar · Answer

Thirs is E

Rupstar · Answer

Fourth is E too

Man this was a tough one...took me 15 minutes to figure out

Whts the OA

lastochka · Answer

A is irrelevant
You know that it's B because of this part "the source of a hot spot remains fixed while a surface plate moves over it,  over a long period of time  an active plume creates a chain of volcanoes "

Earth's surface consists of rigid plates that are

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards