Rapid assembly of high-Mg andesites and dacites by magma mixing at a continental arc stratovolcano
Rapid assembly of high-Mg andesites and dacites by magma mixing at a continental arc stratovolcano
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DOI：
10.1130/g47614.1
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发表时间：
2020-10-01
期刊：
影响因子：
5.8
通讯作者：
Wilson, Colin J. N.
中科院分区：
文献类型：
--
作者：
Conway, Chris E.;Chamberlain, Katy J.;Wilson, Colin J. N.
在活火山喷发前的过程的研究需要精确的岩石年代学的限制，如果他们是在未来的喷发事件的危害评估作出贡献。我们目前的岩石学和地球化学数据和斜方辉石扩散时间尺度的样品从晚更新世高镁安山岩英安岩熔岩（镁# 53-69）在Ruapehu火山，新西兰，作为一个案例研究的快速岩浆成因和喷发在大陆弧成层火山。组装Ruapehu高镁岩浆涉及混合原始岩浆加上夹带地幔平衡橄榄石与中地壳长英质糊状体，产生杂交岩浆无处不在的辉石反向分区模式。与定量晶体取向数据相联系的斜方辉石铁镁互扩散时间尺度表明，
Studies of pre-eruptive processes at active volcanoes require precise petrochronological constraints if they are to contribute to hazard assessment during future eruption events. We present petrological and geochemical data and orthopyroxene diffusion time scales for samples from Late Pleistocene high-Mg andesite-dacite lavas (Mg# 53-69) at Ruapehu volcano, New Zealand, as a case study of rapid magma genesis and eruption at a continental arc stratovolcano. Assembly of Ruapehu high-Mg magmas involved the mixing of primitive magmas plus entrained mantle-equilibrated olivines with mid-crustal felsic mush bodies, yielding hybridized magmas with ubiquitous pyroxene reverse-zoning patterns. Orthopyroxene Fe-Mg interdiffusion time scales linked to quantitative crystal orientation data show that most lavas erupted