Argh GOLD!! Couldn't find anything with the rock hint. I'm doing the IB not A levels so don't have that section. And the only man made thing I could find was the spiral jetty and that only mentions halobacteria in passing.
I've given up. Could someone either give me a final hint or pm me the answer. Thanks
It is alright. The correct answer has two words and I kept putting the second word. Boy I am such a fool. But now know. I simply forgot to put Iron in fornt of the second word!