Q23 - Eight large craters run

[kumarsankara]

Some good explanations above, so I guess I'm just venting at this point. So far, after 5 or 6 practice tests this the question I take most issue with. I get that answer choice B says meteorites could not have caused the craters, but it leaves open that there is any other reason that could cause them other than volcanoes. Answer choice A says here is a similar set of circumstances, (not exact but similar) that was caused by a volcano. If volcanic activity can cause a straight line of craters made at the same time, maybe a series of volcanic activity could cause the same phenomena at different times and a longer line.

End Rant

I guess after writing that I can see how "meteorites definitely didn't cause craters" could be viewed stronger as "maybe volcano did".

[JamesM914]

Ok so I actually registered for this forum specifically for this question. My concern with this question, like many others on this forum, has to do with the "No known natural cause" part of answer choice B. I eliminated B because "no known natural cause" would include volcanoes. Even though this answer choice rules out meteorites as the potential cause, it also rules out volcanoes, which would weaken the conclusion. My question has already been asked several times but nobody has answered it. Somebody PLEASE answer this question. Thanks.

[JingB120]

Even though B has some weird wording here, however, it is still considered to be the best answer in that it's the only answer that has ever mentioned about eight meteorite craters of DIFFERENT AGES, which is explicitly mentioned in the last sentence as a premise that leads to the conclusion. In order to strengthen the argument, all we need to do is to work on the age issue. Volcano can create a lined crater over a long time, while meteorite has only one change to create a lined craters of DIFFERENT AGES. But how? like striking at the same place over and over again?

[DPCTE4325]

Hi melmoththewanderer88,

The “natural” in choice (B) is a great detail to notice. I do think it’s a relevant detail. However, (B) strengthens even if we focus on it. Strengtheners often knock out a specific counterpoint – even very specific counterpoints.

Analogy:

Bob is happy --> Bob ate chocolate

Assumption: nothing other than chocolate makes Bob happy.
Possible right answer: Bob’s happiness isn’t due to a great first date.

^^ Here the strengthener knocks out a very specific counterpoint.

Let’s apply that to this argument:

Craters different ages --> volcanoes rather than meteors

Assumption: there’s no way the meteors could cause different aged craters.
Possible right answer: Meteors can’t cause different aged craters in X specific way.

That’s what (B) gives us.

Curious Fact: What caused the eight linear craters that are all different ages and have high-pressure rocks?

Author's Story: Volcanic events, rather than meteorites, since it's unlikely that it was a bit of both.

Causal Strengthen Tasks:

(1) Rule out an alternate
(2) Increase Author's Plausibility

Here it seems as though since the Author is dubiously siding with volcanic events, it might be worth it to look for an answer that rules out meteorites as a potential cause.

(A) I initially took this as a potential "Cause/Effect" strengthener but it talks about same age craters.

(B) This answer is SO tricky. I initially ruled it out because it said "No known NATURAL cause" to which I thought "meteorites and volcanoes are both natural. This weakens!"

But it says "meteorite craters"; what causes meteorite craters? Well.. I'm assuming meteorites, which is a natural cause. So if there's NO natural cause that could account for meteorite craters, and we know that meteorite craters are a natural cause & that meteorite craters can only be created by meteorites, then this makes it more likely that it was indeed volcanic activity that was the cause.

If you didn't read carefully like me and eliminated this answer after just reading "No known natural cause" then ya we got screwed.

(E) I chose E at first because I thought it ruled out meteorites as an alternate cause. But E doesn't do anything for us since the Author already gives us the premise that the craters are all different ages. What does this mean? That these craters weren't formed all at once! But we know that already.

Thoughts?

[ohthatpatrick]

Nice write-up.

I only got lost a little in terms of what you were saying about (B), specifically:

But it says "meteorite craters"; what causes meteorite craters? Well.. I'm assuming meteorites, which is a natural cause. So if there's NO natural cause that could account for meteorite craters, and we know that meteorite craters are a natural cause & that meteorite craters can only be created by meteorites, then this makes it more likely that it was indeed volcanic activity that was the cause.

That bold sentence doesn't make any sense to me.

Yes, we know that meteorite craters are caused by meteorites, otherwise we'd call them volcanic craters or bomb craters or something else.

This answer is assassinating the plausibility of the meteorite story, because it's saying that there is no physical explanation we could currently dream of that would possibly result in 8 meteorites of different ages creating craters that formed a straight line.

Meaning, with all the randomness of Earth's rotation and revolution and the separate trajectories taken by meteorites reaching Earth at different ages, how could they possibly keep hitting the same tiny spot on Earth?

There's a question on a recent LSAT about a hepadnavirus showing up at the same spot in the chromosomes of two different species. The author speculates that the virus was acquired before these two species diverged on the evolutionary tree.

To strengthen this argument, the correct answer undermines the plausibility of an alternate story (that these two different species each got the h-virus on their own and just happen to have it at the same spot on their chromosome) by saying "where the virus inserts itself into the chromosome is totally random".

That answer has a similar feel to what (B) is doing here. 8 different meteorites, thousands of years apart from each other, would hit Earth at random locations, not all at the same precise spot.

That was the intended gist behind the author's main premise of "Since the craters came from different ages, they probably wouldn't be from meteorites."

(B) is spelling out the assumption: "8 meteorites from different ages wouldn't hit the Earth at the same spot in a long straight line."

[mswang7]

Premises: 8 craters in a line. Craters contain rocks that could've meteorites or volcanos
Linearity makes it unlikely some were volcanos & other metorites
Concl: Different ages -> volcanoes not meteor
Prephrase/gap: Something about linearity, ages & how that makes it more likely to be volcanos

A. if a line of same as craters were caused by volcanos it seems different age should not be volcanes (weakaner)
B. Discusses age, linearity and rules out meteroites
C. Doesn't help us explain volcanoes over metero
D. This is the opposite of what we want since it rules out that the cause was volcanic
E. Answer mentions single meteor shower but that doesn't rule out multiple meteor showers being the cause

[Laura Damone]

Nice work, Mswang!