Due to the slow-moving nature of tectonic plate movement

Due to the slow-moving nature of tectonic plate movement, the oldest ocean crust is thought to date from the Jurassic period, formed from huge fragments of the Earth's lithosphere and lasted 200 million years.

A. formed from huge fragments of the Earth's lithosphere and lasted 200 million years.
B. forming from huge fragments of the Earth’s lithosphere and lasting 200 million years.
C. forming from huge fragments of the Earth’s lithosphere and lasted 200 million years.
D. formed from huge fragments of the Earth’s lithosphere and lasting 200 million years.
E. formed from huge fragments of the Earth’s lithosphere and has been lasting 200 million years.

"formed" can be either Verb-ed modifier or a verb form.

Now "formed" cannot be verb-er modifier as verb-ed modifier should be placed next to the noun it modifies. So "formed" can only modify "Jurassic period" which is not correct.
So formed can be a verb form where
1) is thought to date from the Jurassic period
2) formed from huge fragments of the Earth's lithosphere
3) and lasted 200 million years
Forms a list.

Now
the oldest ocean crust is formed from huge fragments of the Earth's lithosphere. "is" cannot be an auxiliary verb as the sentence requires was.

Can somebody clarify?

Hi,
there has been a bit of confusion on the Q.. lets try to clear a bit of air on it

If we look at it, the Q has more to do with parallelism...
there are three info on the oldest ocean crust:-
1) thought to date from the Jurassic period,
2) formed from huge fragments of the Earth's lithosphere, and
3) lasted 200 million years.

so the sentence can be written as..
Due to the slow-moving nature of tectonic plate movement, the oldest ocean crust is thought to date from the Jurassic period, the oldest ocean crust is formed from huge fragments of the Earth's lithosphere and the oldest ocean crust is lasted 200 million years.....
the sentence is perfect except the usage of "is" and "lasted" together..

so we require to clear this..
HOW DO WE DO IT
lasted is changed to lasting as in D..
But it would have been better had it been "lasting for 200 million years"
Also since it is an activity which began in past and still continuing, we should use PRESENT PERFECT CONTINUOUS rather than simple present..

A BETTER WAY:-

Due to the slow-moving nature of tectonic plate movement, the oldest ocean crust is thought to date from the Jurassic period, is formed from huge fragments of the Earth's lithosphere and has been lasting for 200 million years.
OR
Due to the slow-moving nature of tectonic plate movement, the oldest ocean crust is thought to date from the Jurassic period and formed from huge fragments of the Earth's lithosphere, and has been lasting for 200 million years.

'Formed' and 'lasted' both must modify'the oldest ocean crust'

Let's flip the sentence.
formed from huge fragments, the oldest oceanic crust......

The above sentence makes sense.

lasted 200 million years, the oldest oceanic crust.....

The above sentence doesn't make sense; instead, below is the right way:-
lasting 200 million years, the oldest oceanic crust.....

hence, we must use 'formed' and 'lasting' as in option D.

D is the correct choice.

OFFICIAL SOLUTION

The correct response is (D).

The meaning of the sentence is that the “oldest ocean crust” was “formed” in the past during the Jurassic period and is currently still “lasting” (since if it’s the “oldest” it must still be around!). We need the past tense/participle verbs to be used correctly.

If you chose (A), the ocean crust was “formed” in the past” but if “lasted” is past tense then the oldest ocean crust is no longer around, which would mean it couldn’t be the “oldest.”

If you chose (B) or (C), “forming” implies the crust is still being formed. While it’s true the Earth’s crust is constantly in flux, we’re concerned with the “oldest ocean crust” – that part that is no longer continuing to form, but was formed at some point during the Jurassic period.

If you chose (E), you correctly used “formed,” however the present perfect “has been lasting” is unnecessarily wordy. The simple participle verb form will suffice.

Does logic dictate that (D) is the correct answer? Yes. Will you ignore it because it uses past participle form modifying the previous subject/clause instead of ‘Jurassic Period’? No. Note that it is correct grammatically and you should know it. Whatever we can infer about the preferences of GMAT is from the questions it gives. GMAT doesn’t clarify its stand on every grammatical issue and the stand is probably flexible depending on the sentence under examination. So you need to be flexible in your understanding of what is and is not acceptable in GMAT. Use logic – remember, GMAT is a test of your reasoning skills. Get to the best answer under given circumstances.

Do help me to resolve the doubts mentioned in the thread

In my opinion the modifier "formed from huge fragments of the Earth’s lithosphere and lasting 200 million years" is misplaced. Such placement (end of the clause and separated by comma) is alright for verb modifiers referring to the action (verb) of the previous clause, but such construction for noun modifiers is not ideal.

Moreover note the wrong usage of "due to" in all the options - the correct usage is "because of" in this case.

VeritasKarishma MentorTutoring AjiteshArun

Could you recall any official questions in which verb-ed modifier (formed) jumps over verb: is thought
to modify subject of clause: the oldest ocean crust .

May I know you approach to distinguish between verb-ed (a modifier) and a verb when
helping verbs (is/are/am) are absent?

Hello, adkikani. To answer your first question, no, I cannot think of an official question that uses such a jump for an -ed modifier. There is probably a reason for it, too, and this ties into your second question. You might want to check out this e-GMAT article on the same. It offers far more information than I would dash out in this response, plus the exercises at the end are good practice.

Happy reading.

- Andrew

Not only the question, but the official explanation too seem to be on wrong side :

Excerpts from official explanation :

If you chose (B) or (C), “forming” implies the crust is still being formed. While it’s true the Earth’s crust is constantly in flux, we’re concerned with the “oldest ocean crust” – that part that is no longer continuing to form, but was formed at some point during the Jurassic period.

Present participle modifier "forming" is not conveying the tense of its own but its tense is associated with the tense of the main clause before ",".

Example :
Sam came out the court room, waving his hand to the crowd.

Here, we can't conclude that Sam is still "waving" his hand. Since the main clause of the sentence is in past tense, the action of "waving" too started and completed along with the action of "coming out of court room".

Another example :
He saw a baby crying.

Whether the baby is still crying ? Nope. The tense of "crying" is borrowed from the verb -"saw" - of the sentence. That means that the baby "was" crying when the person saw him/her.

abhishekmayank

You're correct that "forming" draws its tense from the previous clause. However, the previous clause is in the present tense! The mention of the Jurassic Period doesn't change that the sentence says "IS thought to date." Therefore, the OE is correct. B/C are saying that the crust is forming now.

Hi egmat,

Can V-ed modifier (formed) jump over the main verb to modify the Subject sentence (crust) as in the correct choice D?

Thanks

tinbq


I don't know if I have much to add to all the discussion of that issue that has already occurred above. I wouldn't write the sentence this way, but when an awkward modifier jump is the only option we have, we must accept it. We've seen this on an official question, if not specifically with an -ed modifier: https://gmatclub.com/forum/gusty-wester ... 42543.html

As for the trick of making "formed" and "lasting" parallel, I imagine the author must have been trying to copy this famously tricky official question: https://gmatclub.com/forum/scientists-h ... tml#p64997

As usual, the very specific twists that the GMAT has used in carefully-crafted contexts often turn out a bit more shaky and questionable when test prep companies try to reuse them in new contexts.

Can someone explain why E is incorrect

The verb - ed modifier or past participle modifier modifies only the verb or the subject, or both of them but almost never the whole clause. Also, as there is only one subject + verb combination there are no dangling modifiers, hence both formed and lasted refer only to crust. Hope this helps.

Whenever there is a conjunction, we should be cautious for parallelism issues. The portion following the main clause, and modifying it consists of two parts. The first one is formed, which is used in passive form as crust was, once, formed. The second one lasted incorrectly modifies the crust in active form. Both of the sides of the conjunction are modifiers, so the correct sentence should contain either modifiers or verbs, but not mixtures. Choice E turns the second part into a dependent clause, which consists of a modifier and a verb that are obviously not parallel. Lasting is a present participle modifier and always intends that the action is going on in present. The past form will be having lasted and this form appears rarely in GMAT questions, at least as a correct answer. So we do not need to use present perfect tense with the modifier in order to show that it continues till now.

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