No very satisfactory account of the mechanism that caused the formatio

If you don't understand some of the answer choices, all you can really do is rely on process of elimination as far as it will go. If you understand 4 of 5 answer choices well enough to eliminate or keep them, then your move is to just pick the best choice and move on.

This is obviously true when the 4 choices you understand can all be eliminated. But it's still true when you can eliminate 3 choices you understand, and one of the remaining choices seems like the best one -- and I think you're saying that you knew that (E) was a better answer than (A), so the choice sounds like it was fairly clear.

Also, on this particular question type — where each choice contains two words and both must be correct for the choice to be correct — you can attempt to eliminate based purely on one of those two words. You may not be certain what "apprehension" means, but you do know what "slightly" means, and you can determine whether this matches the degree of how this author regards the traditional view. Following through with this example, (B) would be a pretty straightforward elimination, even if we didn't understand the meaning of "indifferent." This tactic might not get you all THAT far, but it can be better than nothing in some cases.

And in the (perhaps very) long run, reading more good, challenging materials will help prevent the vocabulary problem from happening at all. Some suggested reading materials are available here and here.

I hope this helps!

Could someone please help explain to me why option B is correct for Q7? From what line(s), can we specifically refer to to say that the floor of the Black Sea can be compared to a "slowly settling foundation"?

The only mention of the Black Sea comes at the very end of paragraph 3. So what's up with paragraph 3?

This paragraph presents a theory that explains "the enclosed seas," which the author describes as "overlaid by several kilometers of sediment" and "sinking for long periods." Then the author states plainly that the Gulf of Mexico, the Black Sea, and perhaps the North Sea have similar origins to the enclosed seas developing today. So the Black Sea is one example of an enclosed sea, whose basin has formed from sediment that has sunk atop its floor over a long period of time (in other words, a slowly settling foundation).

I hope this helps connect the dots -- er, i mean, the sedimentary layers.

in question 3 why not option number D

Question 3

So we're looking for the answer choice that explains WHY the author brings up this comparison to a conveyor belt. Let's look at the phrase in context one more time:

"The traditional view supposes that the upper mantle of the earth behaves as a liquid when it is subjected to small forces for long periods and that differences in temperature under oceans and continents are sufficient to produce convection in the mantle of the earth with rising convection currents under the mid-ocean ridges and sinking currents under the continents. Theoretically, this convection would carry the continental plates along as though they were on a conveyor belt and would provide the forces needed to produce the split that occurs along the ridge."

In this part of the passage, the author does three things:

1. Describe the traditional view of how the ocean basins were formed
2. Identify a key factor in that traditional view: convection in the mantle
3. Use the image of a conveyor belt to illustrate how this convection would carry and move continental plates

This is a spot-on match for choice (A) ("illustrate the effects of convection in the mantle"), which is why we keep that choice. Now, what's up with choice (D)?


For starters, "the complicated motions made possible by back-coupling" aren't mentioned at all in this portion of the passage. Remember that we're looking for WHY the author mentions the phrase "conveyor belt" — and we've already found that reason in the passage.

The "complicated and varying motions" that could result from back-coupling are mentioned two sentences later. The author brings them up to provide additional support for the first paragraph's overall explanation of how ocean basins were formed.

In other words: Did the author bring up a "conveyor belt" in order to describe "the complicated motions made possible by back-coupling"?

Nope. The conveyor belt comparison served a different purpose in a different part of the passage. That's why we eliminate (D).

Hi Gmatninja, could you please kindly help explain how to approach Q6? Really appreciate it!

Question 6

First, let’s identify what exactly the traditional view of ocean formation is. This view is mentioned in the second sentence of the passage:

The traditional view supposes that the upper mantle of the earth behaves as a liquid when it is subjected to small forces for long periods and that differences in temperature under oceans and continents are sufficient to produce convection in the mantle of the earth with rising convection currents under the mid-ocean ridges and sinking currents under the continents.

The remainder of the first paragraph goes on to further explain the traditional view and lay out its advantages. Then, the second paragraph details a potential flaw in the traditional view, and the author presents an alternative view. Finally, the last paragraph provides a third possible explanation for the formation of the ocean basins.

The questions asks that we identify an answer that supports the traditional view described in the first paragraph. With that in mind, let’s consider the answer choices:


The first sentence of the second paragraph says that the traditional view “is implausible because convection DOES NOT normally occur along lines.” If this is wrong and convection actually DOES usually occur along lines, then the traditional view is PLAUSIBLE. This would definitely support the traditional view of ocean formation. So, let’s keep (A).


In the first paragraph, the author notes that “the traditional view supposes that the upper mantle of the earth behaves as a liquid....” (B) indicates the opposite, so it would definitely not support the traditional view. Eliminate (B).


Sedimentation is mentioned in the final paragraph of the passage as the author discusses the third possible explanation of the formation of ocean basins. But the author does not discuss the rate of sedimentation, and we simply don’t know whether a constant rate would strengthen or weaken the traditional view. In fact, we don’t even know how sedimentation is related to the traditional view. Eliminate (C).


It’s possible that sinking plates do cool the mantle, as is mentioned in the first sentence of the final paragraph. But this possibility is advanced not in favor of the traditional view, but in favor of an alternative view. Eliminate (D).


We already know, based on the final sentence of the passage, that island arcs surround enclosed seas. So, (E) provides no new information, and we can eliminate it.

(A) is the best choice for question 6.

I hope that helps!

GMATNinja egmat KarishmaB mikemcgarry
Could you please help explain the question 2?
I chose E because I thought that the Sea of Japan is actually part of Pacific.

Question 2

The third paragraph tells us that the Sea of Japan has "several kilometers of sediment." None of the other oceans mentioned are said to have sediment, so we'd expect the Sea of Japan to have deeper sediment than the Indian Ocean and the Mid-Atlantic, for instance.

Reading further, we're told "the Gulf of Mexico, the Black Sea, and perhaps the North Sea" are enclosed seas, just like the Sea of Japan. Additionally, they possibly have a "similar origin" to the Sea of Japan. So if they're similar to the Sea of Japan, we'd expect them have lots of sediment.

Let's now consider Question 2:



We're told that the Black Sea is similar to the Sea of Japan, so we can conclude it likely has lots of sediment. Since we have no reason to believe any of the other bodies of water have lots of sediment, (B) is correct.

You mentioned picking (E) because you thought the Sea of Japan was part of the Pacific, but watch out for this kind of assumption. Everything you need to answer these questions should be contained within the passage, so be wary of applying outside knowledge to answer a question (or making guesses about outside knowledge). Instead, see if the passage itself has any clues.

In this case, we're not told anything about the relationship between the Sea of Japan and the Pacific Ocean. However, the information we're given about the Black Sea allows us to draw the proper conclusion.

I hope that helps!

No very satisfactory account of the mechanism that caused the formation of the ocean basins has yet been given. The traditional view supposes that the upper mantle of the earth behaves as a liquid when it is subjected to small forces for long periods and that differences in temperature under oceans and continents are sufficient to produce convection in the mantle of the earth with rising convection currents under the mid-ocean ridges and sinking currents under the continents. Theoretically, this convection would carry the continental plates along as though they were on a conveyor belt and would provide the forces needed to produce the split that occurs along the ridge. This view may be correct: it has the advantage that the currents are driven by temperature differences that themselves depend on the position of the continents. Such a back-coupling, in which the position of the moving plate has an impact on the forces that move it,could produce complicated and varying motions.
Summary: No satisfactory ans to ocean basin formation is found yet. Traditional view is that difference in temperature under ocean and continents because of which oceans base rises near mid ocean ridge and sinks near continents with a movement similar to conveyor belt. Author thinks this view may be correct. Back coupling from temperature difference and continents can result in varying motions.

On the other hand, the theory is implausible because convection does not normally occur along lines. and it certainly does not occur along lines broken by frequent offsets or changes in direction, as the ridge is. Also it is difficult to see how the theory applies to the plate between the Mid-Atlantic Ridge and the ridge in the Indian Ocean. This plate is growing on both sides, and since there is no intermediate trench, the two ridges must be moving apart. It would be odd if the rising convection currents kept exact pace with them. An alternative theory is that the sinking part of the plate, which is denser than the hotter surrounding mantle, pulls the rest of the plate after it. Again it is difficult to see how this applies to the ridge in the South Atlantic, where neither the African nor the American plate has a sinking part.
Summary: Convection does not occur along line and hence above theory cannot be true, Above tehroy cannot be applied to mid atlantic ridge and indian ocean ridge bth of which are growing on both sides. Alternative theory is proposed which states that sinking part of plate pulls the plate after it but it is also skeptical as it cannot be applied in south atlantic ridge which is not having any sining part.

Another possibility is that the sinking plate cools the neighboring mantle and produces convection currents that move the plates. This last theory is attractive because it gives some hope of explaining the enclosed seas, such as the Sea of Japan. These seas have a typical oceanic floor, except that the floor is overlaid by several kilometers of sediment. Their floors have probably been sinking for long periods. It seems possible that a sinking current of cooled mantle material on the upper side of the plate might be the cause of such deep basins. The enclosed seas are an important feature of the earth's surface, and seriously require explanation in because, addition to the enclosed seas that are developing at present behind island arcs, there are a number of older ones of possibly similar origin, such as the Gulf of Mexico, the Black Sea, and perhaps the North Sea.
Summary: Another theory is that sinking plate cool mantle resulting in convection currents which then moves the plate. This theory helps in explaination of enclosed areas such as sea of japan, gulf of mexico,black sea and north sea. Enclosed areas have deep basins.

1. According to the traditional view of the origin of the ocean basins, which of the following is sufficient to move the continental plates?

(A) Increases in sedimentation on ocean floors

(B) Spreading of ocean trenches

(C) Movement of mid-ocean ridges

(D) Sinking of ocean basins

(E) Differences in temperature under oceans and continents.
The traditional view supposes.....and that differences in temperature under oceans and continents are sufficient to produce convection.
this convection would carry the continental plates along as though they were on a conveyor belt

2. It can be inferred from the passage that, of the following, the deepest sediments would be found in the

(A) Indian Ocean
(B) Black Sea
Correct
(C) Mid-Atlantic
(D) South Atlantic
(E) Pacific

3. The author refers to a "conveyor belt" (highlighted text) in order to

(A) illustrate the effects of convection in the mantle.
Coveyor belt is suggested as a result of convection in th mantle.
(B) show how temperature differences depend on the positions of the continents.
(C) demonstrate the linear nature of the Mid-Atlantic Ridge.
(D) describe the complicated motions made possible by back-coupling.
(E) account for the rising currents under certain mid-ocean ridges.

4. The author regards the traditional view of the origin of the oceans with

(A) slight apprehension
(B) absolute indifference
(C) indignant anger
(D) complete disbelief
(E) guarded skepticism
Correct

5. According to the passage, which of the following are separated by a plate that is growing on both sides?

(A) The Pacific Ocean and the Sea of Japan
(B) The South Atlantic Ridge and the North Sea Ridge
(C) The Gulf of Mexico and the South Atlantic Ridge
(D) The Mid-Atlantic Ridge and the Indian Ocean Ridge
correct: the Mid-Atlantic Ridge and the ridge in the Indian Ocean. This plate is growing on both sides

(E) The Black Sea and the Sea of Japan

6. Which of the following, if it could be demonstrated, would most support the traditional view of ocean formation?

(A) Convection usually occurs along lines.
Traditional views states that because of convection, ocean form but counter arguement is that it is implausible because convection does not normally occur along lines.
(B) The upper mantle behaves as a dense solid.
(C) Sedimentation occurs at a constant rate.
(D) Sinking plates cool the mantle.
(E) Island arcs surround enclosed seas.


7. According to the passage, the floor of the Black Sea can best be compared to a

(A) rapidly moving conveyor belt
(B) slowly settling foundation
Correct
(C) rapidly expanding balloon
(D) violently erupting volcano
(E) slowly eroding mountain


8. Which of the following titles would best describe the content of the passage?

(A) A Description of the Oceans of the World
(B) Several Theories of Ocean Basin Formation
Correct
(C) The Traditional View of the Oceans
(D) Convection and Ocean Currents
(E) Temperature Differences Among the Oceans of the World

Hi GMATNinja and other experts, I was having difficulty understanding this passage and hence, took a lot of time but still I couldn't understand it completely. What should be your strategy for such passages where you do not understand what you are reading even though you try hard.

Thanks

That's a great question! A good first step in this case would be to figure out why exactly you're struggling. In some cases, even if someone has sufficient reading skill to understand a text, they struggle because their approach is less than ideal. Sometimes people over focus on details and miss the bigger picture. Sometimes they freeze up because the text seems intimidating, and they neglect to use their intuition and logic. Sometimes the passages are so boring that it's just really hard to care about what you're reading, and as a result, it's almost impossible to engage with what the author is trying to say.

Long story short: sometimes people with fundamentally good reading skills still struggle because they have the wrong approach. If that's the case, the techniques discussed in our Reading Comprehension guide or RC videos could be helpful.

On the other hand, sometimes people have a perfectly good approach, but struggle because their basic reading skill is lacking. While there's no quick way to improve your reading skill, the best way to do that is to delve into challenging texts on a regular basis, so you get used to deciphering and understanding (and perhaps even enjoying) densely written works. If you're looking for some challenging reading material, you can find some suggestions here and here.

I hope that helps!

Q6, nowhere it's written slowly in last para
I didn't understand what settling foundation means 😔

Posted from my mobile device

Question 7

­[Note: This post is about Q7, not Q6.]

In this context, "foundation" refers to the base of a house or building -- it's the bottom-most part on which the entire structure rests.

As a structure is built and weight is added to the foundation, the foundation will "settle" a bit into the soil on which it's built. The heavier the building, the more settling (presumably). And it's not hard to imagine an exceptionally large and heavy building that gradually "sinks" into the earth, little by little, as the decades go by.

Similarly, the ocean floors described in the last paragraph are gradually sinking, as sediment gradually builds up over the millenia, adding more and more weight to the foundation. So (B) is the best option for question 7.

I hope that helps!­