The dramatic scene was caused by one of the Earth's grandest volcanic events. "Around 1.1 billion years ago," says Esther Stewart, a geologist for the Wisconsin Geological and Natural History Survey, "the continent we call North America start
You are free to comment on this discussion in any way you feel is appropriate. If you choose to use to use any language which our editors feel is vulgar -- by their standards -- your comment may be tagged "Crude or Lewd" and may be filtered out of the discussion by those who prefer not to read that sort of thing. If you know you have entered something which will cause your comment to be tagged, we ask that you tag it yourself to save us the time. We do encourage everyone to be civil and not make rude attacks on other people in the Forum. We don't censor out those remarks, but few people enjoy reading them and we would like participation in our Forums to be a pleasant experience for everyone. And, by concentrating on what is said instead of who is saying it, even those who may disagree with you will be more likely to consider your opinions valid.
Thank you for your cooperation!