Aroarotamahine (Green) Lake (Left) and Te Paritu (Blue) Lake (right) occur in the lowest part of the caldera floor. The bulk of the caldera floor that the lakes are based on has been buried by the young dome products, with a lobe of glassy dome lava between the two lakes.
A swampy section of ground lies between the two lakes, although the lakes are not connected on the surface. The near vertical caldera wall was created when the island exploded in the caldera-forming eruption at 6,340 years BP (Buck et al, 1981).
Te Paritu (Blue) Lake on the flat part of the caldera floor looking southwestwards to the summit of Tutaretare Trig.
You can see the series (steps highlighted by the vegetation) of at least 4 thick lava flows that flowed down the flanks of the volcano from a summit vent to form the main cone. That source vent was likely at the summit of the volcano that is now missing. See the image
Aroarotamahine (Green) Lake ponded between the caldera wall, and lobes of the young lava dome (left side of the lake). The lava dome is the youngest (last) eruption product on Mayor Island and it may have been about 500 years ago.
Lunch break at the shore of Aroarotamahine (Green) Lake. Such was the attraction of working and walking over Mayor Island this young (non-geologist) lady voluntered as an unpaid field assistant. Thank you Jannette. Where are you now??
