Oruanui eruption
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The Oruanui eruption of the Taupo volcano is the most recent known eruption that reached an VEI 8. It occured arround 26,500 BP in Late Pleistocene and generated an approximated 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.
