Stories from the Geological Mapping of Karioi Maunga

Following his popular talks on the Geology of Pirongia Volcano (2020), Oliver McLeod has spent the last four years exploring the peaks, valleys, and coastline of Karioi, the ancient volcano towering above the surf of Raglan.

Like her sister Pirongia, Karioi was once the site of violent eruptions that transformed the sleepy, forested hills of Whāingaroa into a rumbling massif of lava and ash. From the ash emerged the Taranaki-like stratovolcano Karioi, which grew and collapsed repeatedly over a 200,000-year period. Now eroded by the swelling ocean and heavy rain, the inner structure of this ancient volcano has been spectacularly exposed along its coastline. The strata reveal a remarkable (and globally unique) story of eruptions that challenge existing ideas about the formation of magmas in the Earth’s mantle. The results have recently been published as a detailed geological map of Karioi and her tamariki, which include over 50 scoria cones and tuff rings of the Okete volcanic field, spread around the onshore and submarine flanks of the maunga.

Local geologist Janine Krippner will open the event providing global volcanological context to Karioi's story.

Signed copies of the new book Geology of Karioi Volcano, Aotearoa New Zealand (published by the Geoscience Society of New Zealand) and individual poster maps will be available for purchase at the event.