GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

It is currently 12 Jul 2020, 10:54

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Geologists have long known that the Earth’s mantle is heterogeneous, b

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Manager
Manager
avatar
G
Joined: 18 Jan 2020
Posts: 71
CAT Tests
Geologists have long known that the Earth’s mantle is heterogeneous, b  [#permalink]

Show Tags

New post 01 Jun 2020, 06:03
5
1
Question 1
00:00
A
B
C
D
E

based on 140 sessions

34% (02:39) correct 66% (02:39) wrong

HideShow timer Statistics

Question 2
00:00
A
B
C
D
E

based on 131 sessions

88% (00:42) correct 12% (00:40) wrong

HideShow timer Statistics

Question 3
00:00
A
B
C
D
E

based on 130 sessions

52% (01:33) correct 48% (01:32) wrong

HideShow timer Statistics

Question 4
00:00
A
B
C
D
E

based on 121 sessions

26% (00:52) correct 74% (00:57) wrong

HideShow timer Statistics

Project RC Butler 2020 - Participate and win GMAT Club Tests.
Passage # 125, Date: 02-Jun-2020
This post is a part of Project RC Butler 2020. Click here for Details


Geologists have long known that the Earth’s mantle is heterogeneous, but its spatial arrangement remains unresolved—is the mantle essentially layered or irregularly heterogeneous? The best evidence for the layered mantle thesis is the well-established fact that volcanic rocks found on oceanic islands, islands believed to result from mantle plumes arising from the lower mantle, are composed of material fundamentally different from that of the midocean ridge system, whose source, most geologists contend, is the upper mantle.

Some geologists, however, on the basis of observations concerning mantle xenoliths, argue that the mantle is not layered, but that heterogeneity is created by fluids rich in “incompatible elements” (elements tending toward liquid rather than solid state) percolating upward and transforming portions of the upper mantle irregularly, according to the vagaries of the fluids’ pathways. We believe, perhaps unimaginatively, that this debate can be resolved through further study, and that the underexplored midocean ridge system is the key.



1. Which of the following best expresses the main idea of the passage?

(A) Current theories regarding the structure of the Earth’s mantle cannot account for new discoveries regarding the composition of mantle xenoliths.
(B) There are conflicting hypotheses about the heterogeneity of the Earth’s mantle because few mantle elements have been thoroughly studied.
(C) Further research is needed to resolve the debate among geologists over the composition of the midocean ridge system.
(D) There is clear-cut disagreement within the geological community over the structure of the Earth’s mantle.
(E) There has recently been a strong and exciting challenge to geologists’ long-standing belief in the heterogeneity of the Earth’s mantle.


2. According to the passage, it is believed that oceanic islands are formed from

(A) the same material as mantle xenoliths
(B) the same material as the midocean ridge system
(C) volcanic rocks from the upper mantle
(D) incompatible elements percolating up from the lower mantle
(E) mantle plumes arising from the lower mantle


3. It can be inferred from the passage that the supporters of the “layered-mantle” theory believe which of the following?

I. The volcanic rocks on oceanic islands are composed of material derived from the lower part of the mantle.
II. The materials of which volcanic rocks on oceanic islands and midocean ridges are composed are typical of the layers from which they are thought to originate.
III. The differences in composition between volcanic rocks on oceanic islands and the midocean ridges are a result of different concentrations of incompatible elements.

(A) I only
(B) III only
(C) I and II only
(D) II and III only
(E) I, II, and III



4. The authors suggest that their proposal for determining the nature of the mantle’s heterogeneity might be considered by many to be
(A) pedestrian
(B) controversial
(C) unrealistic
(D) novel
(E) paradoxical



Please hit Kudos if you like it!
Most Helpful Community Reply
Director
Director
avatar
G
Joined: 05 Jan 2019
Posts: 557
Re: Geologists have long known that the Earth’s mantle is heterogeneous, b  [#permalink]

Show Tags

New post 03 Jun 2020, 01:59
8
1. Which of the following best expresses the main idea of the passage?

(A) Current theories regarding the structure of the Earth’s mantle cannot account for new discoveries regarding the composition of mantle xenoliths
. - the passage presents contrasting views on the spatial arrangement of the earth's mantle; the passage does not make any effort to account for mantle xenoliths.

(B) There are conflicting hypotheses about the heterogeneity of the Earth’s mantle because few mantle elements have been thoroughly studied.
- The first sentence of this passage lets us know that geologists agree that the earth's mantle is heterogeneous.
(C) Further research is needed to resolve the debate among geologists over the composition of the midocean ridge system.
- the geologists are debating over the spatial arrangement of earth's mantle, not over the midocean system's composition.
(D) There is clear-cut disagreement within the geological community over the structure of the Earth’s mantle. - this is what is discussed in the passage. Hence, (D) is the right answer.

(E) There has recently been a strong and exciting challenge to geologists’ long-standing belief in the heterogeneity of the Earth’s mantle. - Not at all mentioned in the passage.

2. According to the passage, it is believed that oceanic islands are formed from


Towards the middle of the first paragraph, we have "oceanic islands, islands believed to result from mantle plumes arising from the lower mantle"

This is what we have in (E)- (E) mantle plumes arising from the lower mantle

Hence, (E) is the right answer choice here.


3. It can be inferred from the passage that the supporters of the “layered-mantle” theory believe which of the following?


I. The volcanic rocks on oceanic islands are composed of material derived from the lower part of the mantle. - mentioned in paragraph 1
II. The materials of which volcanic rocks on oceanic islands and midocean ridges are composed are typical of the layers from which they are thought to originate. - can be inferred from paragraph 1

III. The differences in composition between volcanic rocks on oceanic islands and the midocean ridges are a result of different concentrations of incompatible elements. - not at all mentioned by the proponents of the "layered mantle" theory


(C) I and II only - hence, (C) is the right answer choice


4. The authors suggest that their proposal for determining the nature of the mantle’s heterogeneity might be considered by many to be


(A) pedestrian - this could be used to refer to 'normal'/simply obvious. the author uses the word "unimaginatively", which means that the suggestion is something that the author considers as mundane or fairly obvious. Hence, (A) is the right answer choice.

If you find this explanation helpful, please do give it a kudos :thumbsup: :)
General Discussion
Intern
Intern
avatar
B
Joined: 17 May 2016
Posts: 17
Re: Geologists have long known that the Earth’s mantle is heterogeneous, b  [#permalink]

Show Tags

New post 01 Jun 2020, 09:48
1
Evo23 wrote:
Geologists have long known that the Earth’s mantle is heterogeneous, but its spatial arrangement remains unresolved—is the mantle essentially layered or irregularly heterogeneous? The best evidence for the layered mantle thesis is the well-established fact that volcanic rocks found on oceanic islands, islands believed to result from mantle plumes arising from the lower mantle, are composed of material fundamentally different from that of the midocean ridge system, whose source, most geologists contend, is the upper mantle.

Some geologists, however, on the basis of observations concerning mantle xenoliths, argue that the mantle is not layered, but that heterogeneity is created by fluids rich in “incompatible elements” (elements tending toward liquid rather than solid state) percolating upward and transforming portions of the upper mantle irregularly, according to the vagaries of the fluids’ pathways. We believe, perhaps unimaginatively, that this debate can be resolved through further study, and that the underexplored midocean ridge system is the key.



Which of the following best expresses the main idea of the passage?
(A) Current theories regarding the structure of the Earth’s mantle cannot account for new discoveries regarding the composition of mantle xenoliths.
(B) There are conflicting hypotheses about the heterogeneity of the Earth’s mantle because few mantle elements have been thoroughly studied.
(C) Further research is needed to resolve the debate among geologists over the composition of the midocean ridge system.
(D) There is clear-cut disagreement within the geological community over the structure of the Earth’s mantle.
(E) There has recently been a strong and exciting challenge to geologists’ long-standing belief in the heterogeneity of the Earth’s mantle.


According to the passage, it is believed that oceanic islands are formed from
(A) the same material as mantle xenoliths
(B) the same material as the midocean ridge system
(C) volcanic rocks from the upper mantle
(D) incompatible elements percolating up from the lower mantle
(E) mantle plumes arising from the lower mantle


It can be inferred from the passage that the supporters of the “layered-mantle” theory believe which of the following?
I. The volcanic rocks on oceanic islands are composed of material derived from the lower part of the mantle.
II. The materials of which volcanic rocks on oceanic islands and midocean ridges are composed are typical of the layers from which they are thought to originate.
III. The differences in composition between volcanic rocks on oceanic islands and the midocean ridges are a result of different concentrations of incompatible elements.
(A) I only
(B) III only
(C) I and II only
(D) II and III only
(E) I, II, and III


The authors suggest that their proposal for determining the nature of the mantle’s heterogeneity might be considered by many to be
(A) pedestrian
(B) controversial
(C) unrealistic
(D) novel
(E) paradoxical



Please hit Kudos if you like it!


Can somebody please explain Question 4
Manager
Manager
avatar
S
Joined: 03 Jan 2020
Posts: 106
Location: India
Concentration: Leadership, Entrepreneurship
Schools: ISB, NUS, HEC Montreal, NTU
Premium Member
Geologists have long known that the Earth’s mantle is heterogeneous, b  [#permalink]

Show Tags

New post Updated on: 06 Jun 2020, 07:12
2
All,

This is my first ever post on GMAT Club, so kindly pardon me if it's not up to the mark in terms of following the basic hygiene rule of posting.

I took ~6 min and 30 secs to answer all the questions and still managed to get only 3 right :(

Here's my rationale & mind map:

1st para: Geologists have some unresolved phenomenon and two theories are presented. The first theory is explained
2nd para: The other theory is explained and the author adds her suggestions.

Which of the following best expresses the main idea of the passage?
(A) Current theories regarding the structure of the Earth’s mantle cannot account for new discoveries regarding the composition of mantle xenoliths. - No discussion about new theories not accounting Earth's mantel structure
(B) There are conflicting hypotheses about the heterogeneity of the Earth’s mantle because few mantle elements have been thoroughly studied. Eliminated this because of "a few mantel elements being thoroughly studied". No where in the passage is it mentioned about studying only one element
(C) Further research is needed to resolve the debate among geologists over the composition of the midocean ridge system. Selected this based on POE
(D) There is clear-cut disagreement within the geological community over the structure of the Earth’s mantle. Found the clear cut to be too extreme. And hence eliminated
(E) There has recently been a strong and exciting challenge to geologists’ long-standing belief in the heterogeneity of the Earth’s mantle. No strong & exciting challenges are discussed in the passage


According to the passage, it is believed that oceanic islands are formed from
(A) the same material as mantle xenoliths
(B) the same material as the midocean ridge system
(C) volcanic rocks from the upper mantle
(D) incompatible elements percolating up from the lower mantle
(E) mantle plumes arising from the lower mantleVery straightforward. Refer line 5&6 of 1st para


It can be inferred from the passage that the supporters of the “layered-mantle” theory believe which of the following?
I. The volcanic rocks on oceanic islands are composed of material derived from the lower part of the mantle. Direct quote from line 5 & 6 of 1st para
II. The materials of which volcanic rocks on oceanic islands and midocean ridges are composed are typical of the layers from which they are thought to originate. So this option says Volcanic rocks & midocean ridges are "typical of the layers" which means both are found / created in one particular layer (lower & upper respectively) and are hence typical of that layer
III. The differences in composition between volcanic rocks on oceanic islands and the midocean ridges are a result of different concentrations of incompatible elements. This belongs to the second theory presented in the 2nd para. However we are discussing about the 1st theory
(A) I only
(B) III only
(C) I and II only Correct
(D) II and III only
(E) I, II, and III


The authors suggest that their proposal for determining the nature of the mantle’s heterogeneity might be considered by many to be The author refers to the idea as "unimaginative" in the 3rd last line. My understanding of unimaginative after looking at the answer choices was something which in not unique, novel, unrealistic but rather something which is very obvious and hence pedestrian.
(A) pedestrian
(B) controversial
(C) unrealistic
(D) novel
(E) paradoxical

Originally posted by Iceman2020 on 03 Jun 2020, 11:35.
Last edited by Bunuel on 06 Jun 2020, 07:12, edited 2 times in total.
Manager
Manager
avatar
S
Joined: 03 Jan 2020
Posts: 106
Location: India
Concentration: Leadership, Entrepreneurship
Schools: ISB, NUS, HEC Montreal, NTU
Premium Member
Geologists have long known that the Earth’s mantle is heterogeneous, b  [#permalink]

Show Tags

New post 03 Jun 2020, 11:37
1
kunalc20 wrote:

Can somebody please explain Question 4


Hi kunalc20

Here's my explanation for the 4th question that you requested

The authors suggest that their proposal for determining the nature of the mantle’s heterogeneity might be considered by many to be The author refers to the idea as "unimaginative" in the 3rd last line. My understanding of unimaginative after looking at the answer choices was something which in not unique, novel, unrealistic but rather something which is very obvious and hence pedestrian.
(A) pedestrian
(B) controversial
(C) unrealistic
(D) novel
(E) paradoxical
[/box_in][/box_out][/align]
Director
Director
avatar
G
Joined: 05 Jan 2019
Posts: 557
Re: Geologists have long known that the Earth’s mantle is heterogeneous, b  [#permalink]

Show Tags

New post 29 Jun 2020, 19:48
Hi everyone. If you are looking for some help in the Sentence correction section for the GMAT, feel free to DM me.
GMAT Club Bot
Re: Geologists have long known that the Earth’s mantle is heterogeneous, b   [#permalink] 29 Jun 2020, 19:48

Geologists have long known that the Earth’s mantle is heterogeneous, b

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne