Trace element geochemistry of volcanic gases and particles from 1983–1984 eruptive episodes of Kilauea Volcano
Trace element geochemistry of volcanic gases and particles from 1983–1984 eruptive episodes of Kilauea Volcano
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1983-1984 年基拉韦厄火山喷发事件中火山气体和颗粒的微量元素地球化学
DOI：
10.1029/jb092ib13p13708
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发表时间：
1987
影响因子：
--
通讯作者：
W. Boynton
中科院分区：
文献类型：
--
作者：
B. Crowe;D. L. Finnegan;W. Zoller;W. Boynton
本文获得了基拉韦厄火山东部裂谷带普乌奥口喷发的火山气体和颗粒的成分数据。样品是通过抽烟过滤包系统收集的，该系统由一个前级颗粒过滤器和四个碱基处理过滤器（7LiOH）组成。颗粒和凝聚相被捕获在颗粒过滤器上，酸性气体被收集在处理过的过滤器上。用仪器中子活化分析对30种元素的滤光片进行了分析。从普乌奥奥喷口采集了两个喷发期的油烟样本：(1)第11次喷发后7天（冷却喷口样本）和(2)第13次喷发减弱阶段（活跃喷口样本）。飞机从第17集熔岩喷涌阶段释放的气体羽流中收集了额外的样本（飞机样本）。以挥发性元素Br作为标准化参考元素，以美国地质调查局BHVO-1标准作为岩浆标准，计算了火山烟尘相对源岩浆的富集因子（EFs）。这消除了使用灰分成分（Al， Sc或Mg）作为参考元素所获得的灰分稀释效应。对于Na、K和Cu，溴归一化EFs （× 105）在101 ~ 102之间；Zn、W、Sb、In、Ir、Ag、F、As的含量为102 ~ 105；Au, Cd, Re, Cl， Se和s的富集因子为bbb105。在喷发周期中最富气的阶段收集的飞机样品富集因子最高。金属和挥发性元素数据形成两组：(1)丰度比随样品类型变化很少或没有变化的元素（第1组：Cl、Br和Re）和(2)丰度比随样品类型变化显著的元素（第2组：Zn、W、Sb、in、Ir、Au和Cd）。第一组元素与第二组元素的二元图按样本类型分开。这种分离对应于在喷发活动期间收集的样本和在休息期间收集的样本。监测火山烟雾中的痕量金属比例可以为预测火山爆发提供额外的工具。冷却排气口样品的F/Cl比高于活性排气口或飞机样品，并且该比值与大多数挥发性金属的EFs呈负相关。
Compositional data have been obtained for volcanic gases and particles collected from fume emitted at the Pu'u O'o vent on the east rift zone of Kilauea volcano. The samples were collected by pumping fume through a filter pack system consisting of a front stage particulate filter followed by four base-treated filters (7LiOH). Particles and condensed phases are trapped on the particulate filter, and acidic gases are collected on the treated filters. The filters are analyzed for 30 elements by instrumental neutron activation analysis. Fume samples were collected from the Pu'u O'o vent for two eruptive episodes: (1) 7 days after episode 11 (cooling vent samples) and (2) the waning stage of episode 13 (active vent samples). Additional samples were collected by aircraft from the gas plume released during the lava fountaining phase of episode 17 (aircraft samples). Element concentrations in the vent gases were > 104 μg m−3 for S, Cl, and F. Enrichment factors (EFs) for the volcanic fume versus the source magma were calculated using the volatile element Br as the reference element for normalization and the U.S. Geological Survey standard BHVO-1 as the magma standard. This removes the ash dilution effect obtained by using an ash constituent (Al, Sc, or Mg) as the reference element. Bromine-normalized EFs (× 105) range from 101 to 102 for Na, K, and Cu; 102 to 105 for Zn, W, Sb, In, Ir, Ag, F, and As; and > 105 for Au, Cd, Re, Cl, Se, and S. The highest enrichment factors are for aircraft samples collected during the most gas-rich phase of an eruption cycle. Metal and volatile-element data form two groups: (1) elements showing little or no variation in abundance ratios with sample type (group 1: Cl, Br, and Re) and (2) elements that show significant variation in abundance ratios by sample type (group 2: Zn, W, Sb, In, Ir, Au, and Cd). Bivariate plots of elements of the first group versus elements of the second group separate by sample type. The separation corresponds to samples collected during eruptive activity versus samples collected during repose periods. Monitoring trace metal ratios in volcanic fume could provide an additional tool for predicting volcanic eruptions. The F/Cl ratio of cooling vent samples is higher than those of active vent or aircraft samples, and the ratio is inversely correlated with EFs for most volatile metals.