Jon sez

Yeah, that's a pool of magma over a thousand kilometers across, surrounded by lines of active volcanoes. The fictional bomb described here uses hypothetical (and possibly nonexistent) properties of strangelets.

P.S. Congratulations to the Indian space program for their launch of the Chandrayaan-1 probe to the Moon. The probe will orbit the Moon for two years, mapping it to a five meter resolution and mapping the abundance of a number of elements, among other experiments.