Mayor Island


Mayor Island (Tuhua) is a peralkaline rhyolite volcano located in the Bay of Plenty, New Zealand. It rises 355 meters high and last erupted between 500-1000 years ago.

Geological History

  • Formation: Mayor Island/Tuhua is composed primarily of rhyolitic volcanic rocks, formed from repeated eruptions of viscous lava approximately 7,000 years ago.
  • Caldera Structure: The island’s most prominent feature is a central caldera, formed during a climactic eruption that shaped its topography. Two picturesque crater lakes occupy a portion of the caldera floor.
  • Current Status: While no historical eruptions have been recorded, Mayor Island/Tuhua is considered a dormant volcano. Monitoring suggests that residual magma may exist beneath the island.

Unique Ecosystem and Cultural Significance

    • Obsidian: Mayor Island/Tuhua is a significant source of obsidian, a volcanic glass prized by Māori for its toolmaking properties. The island holds cultural and historical importance for local iwi (tribes).
    • Biodiversity: The island’s protected status as a nature reserve supports a unique and diverse ecosystem, including populations of rare seabirds and endemic plant species.