Oruanui eruption
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The Oruanui eruption of New Zealand's Taupo volcano is the most recent known supervolcanic eruption that reached a VEI of 8 and is the world's largest known eruption in the past 70,000 years. It occurred around 26,500 Before Present in Late Pleistocene and generated approximately 430 km³ of fall deposits, 320 km³ of pyroclastic density-current (PDC) deposits (mostly ignimbrite) and 420 km³ of primary intracaldera material, equivalent to 530 km³ of magma. The eruption is divided into 10 phases on the basis of nine mappable fall units and a tenth, poorly preserved but volumetrically dominant fall unit.
Modern Lake Taupo partly infills the caldera generated during this eruption; a 140 km² structural collapse area is concealed beneath the lake, while the lake outline reflects coeval peripheral and volcano-tectonic collapse. Early eruption phases saw shifting vent positions; development of the caldera to its maximum extent (indicated by lithic lag breccias) occurred during phase 10.
The Oruanui eruption shows many unusual features; its episodic nature, wide range of depositional conditions in fall deposits of very wide dispersal, and complex interplay of fall and PDC activity.
[edit] Further Reading
- Wilson, Colin J. N. (2001). "The 26.5 ka Oruanui eruption, New Zealand: an introduction and overview". Journal of Volcanology and Geothermal Research 112: 133-174. DOI:10.1016/S0377-0273(01)00239-6.
- Manville, Vern & Wilson, Colin J. N. (2004). "The 26.5 ka Oruanui eruption, New Zealand: a review of the roles of volcanism and climate in the post-eruptive sedimentary response". New Zealand Journal of Geology & Geophysics 47: 525-547.
- Wilson, Colin J. N. et al. (2006). "The 26.5 ka Oruanui Eruption, Taupo Volcano, New Zealand: Development, Characteristics and Evacuation of a Large Rhyolitic Magma Body". Journal of Petrology 47 (1): 35-69. DOI:10.1093/petrology/egi066.
