The ~AD1315 Tarawera and Waiotapu eruptions, New Zealand: contemporaneous rhyolite and hydrothermal eruptions driven by an arrested basalt dike system?
The ~AD1315 Tarawera and Waiotapu eruptions, New Zealand: contemporaneous rhyolite and hydrothermal eruptions driven by an arrested basalt dike system?
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~AD1315 新西兰塔拉威拉和怀奥塔普火山喷发：由停止的玄武岩岩脉系统驱动的同期流纹岩和热液喷发？
DOI：
10.1007/s00445-004-0373-7
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发表时间：
2005
影响因子：
3.5
通讯作者：
P. Shane
中科院分区：
文献类型：
--
作者：
I. Nairn;J. W. Hedenquist;P. Villamor;K. Berryman;P. Shane
一系列大型热液喷发发生在整个怀奥塔普地热田大约相同的时间（史前）从塔拉韦拉火山喷口，10-20公里远的~ AD 1315“Kaharoa”流纹岩岩浆喷发。怀奥塔普热液喷发的触发以前归因于邻近的Ngapouri断层的位移。卡哈罗流纹岩喷发现在被认为是由塔拉韦拉火山下的多个玄武岩侵入体引发的。外奥塔堡地热威尔斯井岩芯样品中的蚀变矿物学和流体包裹体记录了~1000 t/d的CO2气体脉冲。这种CO2脉冲最容易来源于侵入深处的玄武岩，虽然没有精确的日期，但似乎与怀奥塔普热液喷发有关。我们推断，在怀奥塔普的热液喷发是由同一逮捕玄武岩岩脉系统，推动流纹岩喷发在塔拉韦拉入侵。这个岩脉系统在深度上可能与公元1886年在塔拉威拉地区形成的17公里长的裂缝中产生玄武岩喷发的岩脉相似。与AD 1886和~ AD 1315喷发相关的Waiotapu地区发生的断层破裂被认为是堤坝侵入过程的结果，而不是原因。
A series of large hydrothermal eruptions occurred across the Waiotapu geothermal field at about the same (prehistoric) time as the ~AD1315 “Kaharoa” rhyolite magmatic eruptions from Tarawera volcano vents, 10–20 km distant. Triggering of the Waiotapu hydrothermal eruptions was previously attributed to displacement of the adjacent Ngapouri Fault. The Kaharoa rhyolite eruptions are now recognised as primed and triggered by multiple basalt intrusions beneath the Tarawera volcano. A ~1000 t/day pulse of CO2 gas is recorded by alteration mineralogy and fluid inclusions in drill core samples from Waiotapu geothermal wells. This CO2 pulse is most readily sourced from basalt intruded at depth, and although not precisely dated, it appears to be associated with the Waiotapu hydrothermal eruptions. We infer that the hydrothermal eruptions at Waiotapu were primed by intrusion of the same arrested basalt dike system that drove the rhyolite eruptions at Tarawera. This dike system was likely similar at depth to the dike that generated basalt eruptions from a 17 km-long fissure that formed across the Tarawera region in AD1886. Fault ruptures that occurred in the Waiotapu area in association with both the AD1886 and ~AD1315 eruptions are considered to be a result, rather than a cause, of the dike intrusion processes.