Journalist: The end of the Triassic, the geologic period that extended

Question

Journalist: The end of the Triassic, the geologic period that extended from about 250 to 200 million years ago, has traditionally been blamed on volcanic eruptions that went on for 600,000 years. However, a researcher has recently suggested that these eruptions were only an indirect cause. By analyzing the isotopic composition of hydrocarbon molecules from plant waxes from the period, he discovered what looks like a spike in the amount of non biological carbon in the atmosphere, lasting between 10,000 and 20,000 years. The researcher believes that the release of methane—a carbon-containing greenhouse gas much stronger than carbon dioxide—stored at the bottom of the ocean was the direct cause of the end of the Triassic.

The journalist suggests that a certain causal sequence may have brought about the end of the Triassic period. Identify in the table the sequence of cause and effect most strongly suggested by the journalist to have resulted in the end of the Triassic. Make only two selections, one in each column.

The journalist suggests that a certain causal sequence may have brought about the end of the Triassic period. Identify in the table the sequence of cause and effect most strongly suggested by the journalist to have resulted in the end of the Triassic. Make only two selections, one in each column.

Sajjad1994 · Accepted Answer

Official Explanation

The wording of the passage suggests that the answers may depend on one another, in that the correctness of one response may depend on the correctness of the other.

Although volcanoes emit various gases, such emissions are not claimed by the journalist to have brought about the end of the Triassic. The journalist indicates that volcanic eruptions were an indirect cause of the end of the Triassic. The eruptions might thus have been a cause of the end of the Triassic, but only because of certain effects that they had. The journalist then indicates that the release of methane from the bottom of the ocean was the direct cause of the end of the Triassic. This very strongly suggests that, according to the journalist, the eruption of volcanoes—an indirect cause of the end of the Triassic—resulted in a release of methane from the bottom of the ocean, which in turn resulted in the end of the Triassic.

The correct answer are The eruption of volcanoes and The release of methane from the bottom of the ocean.

HG0815 · Answer

IMO, cause : The release of methane from the bottom of the ocean
 effect : The reelase of carbon dioxide into the atmostphere

A.The emissions of volcanoes into the atmosphere
-> The journalist argues that emissons of volcanoes are indirect reason. 
B.The extinction of many oceanic biological species
-> Not mentioned
C.The eruption of volcanoes
-> Same as A 
D.The release of carbon dioxide into the atmosphere
-> The journalist argues that there was 'the amount of nonbiological carbon in the atmosphere'.
 So it would be effect.
E.The release of methane from the bottom of the ocean
-> The journalist argues that the release of methan is direct cause. So cause is E

I am not sure this is correct. If not, is there anyone who can let me know what is correct?

srishti246 · Answer

Could someone explain the answer to this?

Shouldn't the cause be release of methane and effect be volcano eruption?

Mona2019 · Answer

As per my understanding, 
one of the statements in the question is :
However, a researcher has recently suggested that these eruptions  were only an indirect cause.  - I

so , the researcher is not ruling out this cause, instead stating it as an indirect cause. 
Then the researcher mentions methane at the bottom of the ocean to be the cause. (implying direct cause) -II

so I can be the cause and II the effect - which means II becomes the direct cause of the extinction and I is the indirect cause .

CEdward · Answer

Not sure this is the greatest question...unless you knew what the "Triassic period" was...presumably it was the age of the dinosaurs.

Cause: Release of methane from the bottom of the ocean
Effect: Extinction of many species

Cause-----Effect

--- ---------- ---------The emissions of volcanoes into the atmosphere
--- ---------- ---------The extinction of many oceanic biological species
--- ---------- ---------The eruption of volcanoes
--- ---------- ---------The release of carbon dioxide into the atmosphere
--- ---------- ---------The release of methane from the bottom of the ocean

zoezhuyan · Answer

dear  Sajjad1994

why strongly suggest that the eruption of volcanoes resulted in a release of methane from the Botton of the ocean

Sajjad1994 · Answer

The journalist starts by mentioning that the traditional view is that volcanic eruptions caused the end of the Triassic period. However, the journalist goes on to say that a researcher has suggested a different, more direct cause for the end of the Triassic. The researcher believes that the release of methane from the bottom of the ocean was the direct cause of the end of the Triassic. Therefore, the sequence of cause and effect most strongly suggested by the journalist is the eruption of volcanoes causing the release of methane from the bottom of the ocean, leading to the end of the Triassic period.

Option A  is incorrect because the journalist suggests that volcanic emissions may have been an indirect cause, not the direct cause.

Option B  is incorrect because the journalist does not mention the extinction of many oceanic biological species as a cause of the end of the Triassic period.

Option D  is incorrect because the journalist does not mention the release of carbon dioxide into the atmosphere as a cause of the end of the Triassic period.

zoezhuyan · Answer

Dear  Sajjad1994

I am little confused, why the indirected cause, volcanic eruptions, will cause the direct one, the release of methane from the bottom of the ocean

in my opinion, indirect cause is just not the direct the cause of end , but it is highly possible that the indirect cause combines with other factors to lead end, while it is not necessary to caue the direct cause.

Thanks for your further clarify.

Posted from my mobile device

Sajjad1994 · Answer

I am not sure what exactly you want to say in the highlighted lines above, In my opinion thinking your way will only make the question unnecessarily confusing. Just read in the question statement  what researcher want to say . The answer is based on the interpretation of the researcher.

"The journalist indicates that volcanic eruptions were an indirect cause of the end of the Triassic. The eruptions might thus have been a cause of the end of the Triassic, but only because of certain effects that they had. The journalist then indicates that the release of methane from the bottom of the ocean was the direct cause of the end of the Triassic."

This make us reach the answer easier and give us the sequence of what is direct and what is indirect. We don't need to know each and every step of this whole process rather we just need to know what is direct and what is indirect effect of ending the Triassic.

SajalM · Answer

Have been using Gemini lately to help break down answer to the problem and I think the A.I did a pretty good job of breaking down the argument. Summarized here :

Understanding the Prompt:

The prompt asks us to identify the causal sequence that the journalist suggests led to the end of the Triassic period. In simpler terms, we need to figure out what caused what.

Key Points from the Text:

Traditional Belief: Volcanic eruptions lasting 600,000 years were initially blamed for the end of the Triassic.
New Research: A researcher found evidence of a spike in non-biological carbon (likely from methane) in the atmosphere.
Direct Cause: The researcher believes the release of methane from the ocean floor was the direct cause of the extinction.
Analyzing the Options:

We're given five options, each representing a potential cause or effect. Let's break them down:

Option 1: The emissions of volcanoes into the atmosphere: This is a potential cause, as the journalist initially mentioned volcanic eruptions as a factor.
Option 2: The extinction of many oceanic biological species: This is a potential effect, as the release of methane could have led to environmental changes that caused extinctions.
Option 3: The eruption of volcanoes: This is the same as Option 1, so it's redundant.
Option 4: The release of carbon dioxide into the atmosphere: While this could be a consequence of volcanic eruptions, the text specifically mentions methane as the main culprit.
Option 5: The release of methane from the bottom of the ocean: This is the direct cause identified by the researcher.
Identifying the Causal Sequence:

Based on the text, the most likely causal sequence is:

Volcanic Eruptions: This is the initial cause suggested by the traditional belief.
Release of Methane: The researcher found evidence that volcanic eruptions led to the release of methane from the ocean floor.
Extinction of Species: The release of methane, a potent greenhouse gas, would have caused significant environmental changes, leading to the extinction of many species.

Conclusion:

The journalist suggests that volcanic eruptions were the indirect cause of the end of the Triassic period, leading to the release of methane from the ocean floor, which was the direct cause of the extinction event.

ShubhadeepB · Answer

As I am reading the passage, I get a sense that the journalist believes there's something more leading to the end of the Triassic period. And, bingo! The new evidence suggests that the release of methane into the atmosphere was the direct reason of the end of the Triassic. We already know that volcanic eruptions are an indirect cause. Therefore, the causality should be volcanic eruptions ---> release of methane into the atmosphere ---> end of Triassic. So, the journalist does not oppose the traditional view, but instead, adds more nuance to that view by differentiating between a direct and an indirect cause. Any questions?

tabishjaved · Answer

Concept of Direct-Indirect Cause vs Primary-Secondary Cause:

IC: A  -> B  -> E 
SC: A  -> E, but B  -> E more
A chain vs 2 separate

Solution:
Eruption of volcanoes     -> Release of methane     -> End of Triassic    
Among the options we have to find either..
1 -> 2........
or
........2 -> 3

consistentprep · Answer

Between two options:
The emissions of volcanoes into the atmosphere
The eruption of volcanoes ✅ (correct cause)

The GMAT prefers the most directly stated event in the passage.
The text says “volcanic eruptions that went on for 600,000 years” — it never says “emissions” as a separate event. Emissions are part of eruptions, but the passage frames the eruption itself as the initiating factor.
So "emissions of volcanoes" is too narrow and wasn’t the main starting point in the journalist’s chain.

Why this matters for the GMAT question
 
  Cause column : pick the  first link  in the relevant chain →  Volcanic eruptions  
  Effect column : pick the  immediate next link  caused by that event →  Release of methane from the bottom of the ocean   
Everything after step 2 is still part of the story, but it’s  downstream , so GMAT won’t pick it as the “effect” in this particular cause–effect pairing.

2019ms8915 · Answer

how can i say volcanic eruption had an effect of releasing methane stored at the bottom of the ocean???

Bunuel · Answer

The passage says:

Traditionally, volcanic eruptions were blamed. 
 New research: eruptions were only an  indirect  cause. 
 Eruptions likely triggered the release of methane stored at the ocean bottom. 
 That methane release directly caused the end of the Triassic (mass extinction).

So the journalist’s suggested sequence is:
 
Cause:  The eruption of volcanoes
  Effect:  The release of methane from the bottom of the ocean

The passage itself provides the link. It says the volcanic eruptions were an  indirect  cause of the end of the Triassic. That implies the eruptions triggered some chain reaction rather than directly causing the extinctions. The researcher then identifies the release of methane from the ocean floor as the  direct  cause. Putting those two together, the only way eruptions fit into the explanation is as the event that destabilized conditions (for example, heating, pressure changes, or disturbance in the oceans) and led to methane being released.

So you don’t have to supply outside geological knowledge about  how  exactly the eruptions released methane. You just follow the causal link the journalist lays out:

Volcanic eruptions --> indirect cause 
 Methane release --> direct cause

That’s why the correct chain is “eruption of volcanoes” (cause) leading to “release of methane from the bottom of the ocean” (effect).

Hope it's clear.

ChiranjeevSingh · Answer

Passage Analysis

The end of the Triassic, the geologic period that extended from about 250 to 200 million years ago, has traditionally been blamed on volcanic eruptions that went on for 600,000 years.

This sentence talks about Triassic, which is a geologic period that extended from 250 million years ago to 200 million years ago. The end of this period, which happened 200 million years ago, has traditionally been blamed on volcanic eruptions. So the sentence talks about something that has been a traditional idea, so I can expect the upcoming sentences to talk about the new idea.

These volcanic eruptions went on for 600,000 years, which is 0.6 million years. These volcanic eruptions must have happened around 200 million years ago. (It's important to note that I would process the statement in the way I have shared. I just don't read a statement and move on. I assimilate it deeply before moving on.)

However, a researcher has recently suggested that these eruptions were only an indirect cause.

The sentence starts with a  contrast , which is not surprising given that I was expecting the upcoming sentences to present a new idea. It says that a researcher has recently suggested something. What is that? That these eruptions were  only an indirect cause .

It's important to understand this clearly: we are not saying that these eruptions are not even a  cause . We are just saying that they are only an  indirect cause , so they are not the  direct cause . What is the difference between a direct and  indirect cause ? First of all, we need to be clear that an  indirect cause  is still a  cause , so we are not ruling out the  causality . It is just  indirect .

Given the wording, I can understand that the  direct cause  has to be something that is directly leading to the  effect , whereas an  indirect cause  would be something that is somewhere behind in the  chain of causality . So for example, if X leads to Y and Y leads to Z, then Y is the  direct cause  of Z and X is the  indirect cause  of Z.

By analyzing the isotopic composition of hydrocarbon molecules from plant waxes from the period, he discovered what looks like a spike in the amount of non biological carbon in the atmosphere, lasting between 10,000 and 20,000 years.

Here I have to admit that I don't know the meaning of  isotopic composition , so I understand the sentence in this way: that the researcher analysed some composition of the hydrocarbon molecules, and these hydrocarbon molecules are from plant waxes from the period. Which period? That geologic period we have talked about. So in essence, the researcher is analysing something from that period and he is discovering a significant increase in the amount of  non-biological carbon . I don't know what  non-biological carbon  means, just that some form of carbon was significantly higher in the atmosphere for about 10,000 to 20,000 years.

As I read this complex technical sentence, I focus on the essence. Given our understanding so far of the passage, this sentence must be leading us in the direction to say that volcanic eruptions were only an  indirect cause  and something else was the  direct cause . Now we get to know that there was a significant increase in the amount of non-biological carbon. This could be the  direct cause  of the end of the period, but I'm not sure.

The researcher believes that the release of methane—a carbon-containing greenhouse gas much stronger than carbon dioxide—stored at the bottom of the ocean was the direct cause of the end of the Triassic.

The sentence talks about methane, which also contains carbon and is much stronger than carbon dioxide in terms of its greenhouse effect. The researcher believes that the release of this gas, methane, from the bottom of the ocean was the  direct cause  of the end of the period.

Okay, so now let's try to weave it all together. Methane was released from the bottom of the ocean. How do we say that? Because of the last sentence: that there was a significant increase in the amount of non-biological carbon. So the researcher looks at that increase and thinks that there was a release of methane from the bottom of the ocean, and believes that this was the  direct cause  of the end of that period.

And we know that we were saying that the volcanic eruptions were an  indirect cause . So perhaps volcanic eruptions caused methane to be released from the bottom of the ocean, and then this release of methane caused the end of the Triassic. This is a  chain of causality  presented here. Again, I would like to highlight that I would make all these connections before even looking at the question. That is the way I read.

Question Analysis

The journalist suggests that a certain causal sequence may have brought about the end of the Triassic period. Identify in the table the sequence of cause and effect most strongly suggested by the journalist to have resulted in the end of the Triassic. Make only two selections, one in each column.

In this question, we are supposed to find a  cause  and  effect  that eventually resulted in the end of the Triassic. So we have a  cause , then we have an  effect , and the  effect  leads to the end of the Triassic. Given our understanding of the passage, we already have this  chain  in place: The volcanic eruptions leading to the release of methane, and the release of methane leading to the end of the Triassic.

Options Evaluation

(A) The emissions of volcanoes into the atmosphere

Incorrect.    This option is wrong for two reasons:  emissions  are not the same as  eruption  of volcanoes.

And secondly, given the context of the passage, I would expect the eruption of volcanoes to be inside the ocean so that they release methane stored at the bottom of the ocean, so I wouldn't expect the eruption to be  into the atmosphere .

Given our discussion above, the correct answers are   The eruption of volcanoes    (   Cause   ) and    The release of methane from the bottom of the ocean    (   Effect   )

Journalist: The end of the Triassic, the geologic period that extended

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Cause	Effect
		The emissions of volcanoes into the atmosphere
		The extinction of many oceanic biological species
		The eruption of volcanoes
		The release of carbon dioxide into the atmosphere
		The release of methane from the bottom of the ocean

GMAT Two-part Analysis (TPA) Questions

Journalist: The end of the Triassic, the geologic period that extended

Prep Toolkit

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

More than Quant/Verbal Abilities: Speed vs. Accuracy

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My Rewards