Mangakino Caldera

However this was only in its most recent caldera forming phase from 1.21 to 0.91 million years ago as it had its earliest caldera generating phase from 1.62 to 1.51 million years ago. At least 5 of these contributed significant welded ignimbrite deposits that represent major pyroclastic events in the central North Island. Ongatiti Ignimbrite (Hinuera Stone) from a 7 VEI event, about 1.3 million years ago, has now been found over a wider area and several meter thick tephra deposits from the eruption exist on drill samples from both Auckland and Wellington.