The credited response D, seems like a very weak choice. No where in the stim does it say that the boulder came from the last ice age, maybe it came from an ice age before when the glacier that deposited it was actually an east moving glacier, also it assumes that we understand how boulders move through glaciers. Maybe they move east to west in a southward moving glacier. I just felt that this question really made us assume a lot. I chose A knowing full well that "most" does not necessarily mean all, but I still thought it better than all of the assumptions that were required for D. It seems like a lot of the new LR are definitely not even close to airtight. I seem to always get 3 or so of the non-airtight questions wrong on a newer test.
I would love to hear some other people's thoughts about this question and why D is the best.
PT 56 Section 2 Question #8 LR Forum
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Re: PT 56 Section 2 Question #8 LR
A is an ok choice but not the BEST choice. The question ask for MOST seriously undermine.
B: its irrelevant, it doesn't address the north where it would have come from
C: strengthens
E: doesn't apply since the stimulus said moved hundreds of miles.
so it's between A and D. D however states that no source of volcanic source exist to the north in this south-moving glacier. So then the rock most likely has to come to where it is now by some other means (stimulus says the glacier moved it which would be impossible if there is no source to the north). A is a ok choice because it shows that most have not been moved 100 miles but it doesn't mean this one couldn't have.
add: you probably focused on challenging how far it was moved rather than how it was moved there. D challenges the latter directly while A challenge the former weakly
B: its irrelevant, it doesn't address the north where it would have come from
C: strengthens
E: doesn't apply since the stimulus said moved hundreds of miles.
so it's between A and D. D however states that no source of volcanic source exist to the north in this south-moving glacier. So then the rock most likely has to come to where it is now by some other means (stimulus says the glacier moved it which would be impossible if there is no source to the north). A is a ok choice because it shows that most have not been moved 100 miles but it doesn't mean this one couldn't have.
add: you probably focused on challenging how far it was moved rather than how it was moved there. D challenges the latter directly while A challenge the former weakly
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Re: PT 56 Section 2 Question #8 LR
Our conclusion is the following:
This boulder was probably deposited here, hundreds of miles from its geological birthplace, by a glacier
Premise 1:
The boulder is volcanic in origin
Premise 2:
The rest of the rock is sedimentary
Premise 3: This area was covered by southward-moving glaciers during the last ice age (note: this means that the glaciers were moving from somewhere North of this area to somewhere South of this area)
If a boulder was deposited during a southward migration, that glacier must have come from somewhere North of the area. Therefore, if a boulder of volcanic origin was deposited, there must have been some source of volcanic boulders North of the area. If as stated by answer D, there are no sources of volcanic boulders North of the area, then the boulder could not have been deposited in the way proposed by this theory.
With all due respect, I don't think that it's asking too much for them to assume that you will think something that is "southward-moving" is moving from North to South. Now, if they wanted you to guess that a "southward" movement was happening from east to west, that would absolutely need to be stated. Also, I'm not sure how it matters whether the boulder came from the last ice age. If there were never any sources of volcanic activity to the north, the theory proposed in the stimulus is not logical.
A -- if boulders haven't moved more than 100 miles, that does not undermine the conclusion. The conclusion is just as strong if the boulder moved from 75 miles to the North
B -- just because the closest is to the South doesn't undermine the theory that the boulder came from a further source to the North
C -- additional evidence in support of the theory
D -- as I've said above, if there are no sources to the North, a southward migration did not deposit the boulder
E -- the exact distance doesn't matter, the point is the direction of origin
Hope that helps.
This boulder was probably deposited here, hundreds of miles from its geological birthplace, by a glacier
Premise 1:
The boulder is volcanic in origin
Premise 2:
The rest of the rock is sedimentary
Premise 3: This area was covered by southward-moving glaciers during the last ice age (note: this means that the glaciers were moving from somewhere North of this area to somewhere South of this area)
If a boulder was deposited during a southward migration, that glacier must have come from somewhere North of the area. Therefore, if a boulder of volcanic origin was deposited, there must have been some source of volcanic boulders North of the area. If as stated by answer D, there are no sources of volcanic boulders North of the area, then the boulder could not have been deposited in the way proposed by this theory.
With all due respect, I don't think that it's asking too much for them to assume that you will think something that is "southward-moving" is moving from North to South. Now, if they wanted you to guess that a "southward" movement was happening from east to west, that would absolutely need to be stated. Also, I'm not sure how it matters whether the boulder came from the last ice age. If there were never any sources of volcanic activity to the north, the theory proposed in the stimulus is not logical.
A -- if boulders haven't moved more than 100 miles, that does not undermine the conclusion. The conclusion is just as strong if the boulder moved from 75 miles to the North
B -- just because the closest is to the South doesn't undermine the theory that the boulder came from a further source to the North
C -- additional evidence in support of the theory
D -- as I've said above, if there are no sources to the North, a southward migration did not deposit the boulder
E -- the exact distance doesn't matter, the point is the direction of origin
Hope that helps.