It can be inferred from the passage that which one of the following was true of the lava that erupted in India at the...

shunhe July 15, 2020

Hi @iris.diaz823,

Thanks for the question! So first, let me talk about why (D) is right. Remember, we’re looking for something we can infer from the passage that has to do with the lava that erupted in India at the end of the Cretaceous period. Take a look at lines 13-14, where we’re told that iridium is extremely rare in rocks on the Earth’s surface, and that it’s common in meteorites. Now take a look at where we’re told about the lava that erupted in India, which is around 39-47. There, we’re told that (again) although iridium is extremely rare on the surface of the Earth, the lower regions of the mantle have roughly the same composition as meteorites (which have more than the earth’s surface) and have a bunch of iridium. That would be blown out in the lava that erupted, and so the lava would be richer in iridium than rocks usually found on the Earth’s surface, which is why (D) is correct.

Now take a look at (C), which tells us that we can infer that the eruption released enough iridium hexafluoride into the atmosphere to change the Earth’s climate dramatically. But here’s the thing, although we are told that iridium hexafluoride would be released (around lines 43-44), we aren’t told anything about its environmental impact. In fact, we’re actually told that it’s the carbon dioxide (not iridium hexafluoride) that caused the climate change responsible for dinosaurs’ extinctions in lines 23-26. Because (C) goes too far in saying that the iridium hexafluoride is the cause of the climate change, we can eliminate it as something not supported by the passage.

Hope this helps! Feel free to ask any other questions that you might have.

iris.diaz823 August 4, 2020

Thank you!

Natalee-Geerts September 1, 2020

I have read over the passage that you said referred to India and I couldn't find India in the passage anywhere. I got to the question and didn't know how to answer it because I don't see anywhere where India, specifically, is mentioned. I still don't understand how you know that lines 39-47 refer to India. I thought that since a lot of the reading comprehension questions are must be true questions you would have to find exact evidence for D to be said about India, but it doesn't mention India anywhere! Would the answer have been different if they chose a different location? Why or why not?

KatyMiller February 1, 2021

@natalee, I think he meant to say India is mentioned in line 21 "a vast eruption of lava in India..."