Structure of the Earth
Macquarie Island, off Tasmania, is at the meeting-point of two huge oceanic plates: the Pacific Plate and the Indo-Australian Plate. The island is made of material pushed up from deep in the Earth's mantle.  It is thought that the green ophiolite rock was formed at the moho, and was brought up by a mid-oceanic ridge. Now it comes to the surface because the two plates are scrunching together. It is the only place on Earth where this is happening at present. There are other places where ophiolite is found, but they were brought up many millions of years ago. Ophiolites are found in all the major mountain belts of the world.