Pigeon Mountain/O Huiarangi

Pigeon Mt is the easternmost of Auckland's 53 young basalt volcanoes. It erupted 23,000 years ago. It erupted in the usual succession of three different styles. The first style was wet with explosive eruptions creating a wide explosion crater with a tuff ring of hardened ash around it. From Pigeon Mt, the highest part of the tuff ring can be seen out to the north beneath Half Moon Rise. The depression between Pigeon Mt and the tuff ring today (Brittania Place) is partly the explosion crater and partly the hole left where half the scoria cone was quarried away.
After all ground water was exhausted the eruption switched to dry, with fountaining of frothy lava. This cooled and solidified to scoria and accumulated as a steep scoria cone around the vent in the middle of the crater. Only half of the scoria cone survives after quarrying removed the northern half.
At the same time as fountaining, degassed lava flowed out from the western base of the scoria cone and down the small valley towards the Tamaki River. It flowed nearly 1 km and is now mostly hidden beneath grass and bush in the reserves. Some hard basalt rocks of the flow can be seen around the head of Wakaaranga Creek in the reserve, Look where the long grass passes into salt marsh or mangroves.

Climb Pigeon Mt and look around for remnants of the tuff ring to the north.
Imagine what the cone was like before half was quarried away.
Can you see any other of Auckland's volcanic cones from here?
Why are there pits or depressions on the crest of Pigeon Mt?
Walk down the walkway to the west following the route of the lava flow and look for solid basalt rocks at the head of Wakaaranga Creek estuary.