'This is pretty spectacular!' Massive sinkhole on Rotorua farm exposes 60,000-year-old volcanic deposits

A massive sinkhole which opened up on a Rotorua farm has been called "spectacular" by a geologist who says it has exposed 60,000-year-old volcanic deposits at the base of the hole.

Volcano Information Specialist Bradley Scott says sinkholes aren't rare in Rotorua but this week's one is very large. Source: 1 NEWS

The sinkhole, which is estimated to be 200m long, 30m wide and 20m deep, opened up in the paddock after a deluge of rain caused a state of emergency to be declared in the region on Sunday.

Volcano Information Specialist Bradley Scott told 1 NEWS the massive hole has exposed some interesting history.

"What I see in the bottom of this hole is the original 60,000-year-old volcanic deposit that came out of this crater.

"Then there's a stack of about 10 to 12 metres of sediment sitting on top of it from lakes that have formed in this crater the top three metres is volcanic ash," Mr Scott says.

Although sinkholes are common in the Rotorua region due to its volcanic history, this one is a bit different.

"This is pretty spectacular and it's a lot bigger than the ones I normally see."