No two volcanoes are the same, but they all form in the same handful of ways. All, it seems, except for the ancient volcano forming the foundations of the island of Bermuda.

After examining rocks from deep under the island, scientists discovered that this quiet volcano formed in a way that is, so far, completely unique. The work, reported this week in the journal Nature, not only solves a long-standing mystery about this beautiful isle in the Atlantic, it also describes a whole new way to make a volcano. (Explore the volcanoes that make up the Pacific Ring of Fire.)

To crack the case, the team examined a 2,600-foot-long pillar of rock that is the only core sample taken from