The ion microprobe as a tool for obtaining strontium isotopes in magmatic plagioclase: A case study at Okataina Volcanic Centre, New Zealand
The ion microprobe as a tool for obtaining strontium isotopes in magmatic plagioclase: A case study at Okataina Volcanic Centre, New Zealand
复制标题
离子微探针作为获取岩浆斜长石中锶同位素的工具：新西兰奥卡泰纳火山中心的案例研究
DOI：
10.1016/j.chemgeo.2019.03.016
复制
发表时间：
2019
期刊：
影响因子：
3.9
通讯作者：
Yurimoto, Hisayoshi
中科院分区：
文献类型：
--
作者：
Sas, May;Kawasaki, Noriyuki;Sakamoto, Naoya;Shane, Phil;Zellmer, Georg F.;Kent, Adam J.R.;Yurimoto, Hisayoshi
我们调查了潜在的多收集器二次离子质谱（MC-SIMS）作为一种工具，用于获得Sr同位素组成的斜长石，一种普遍存在的矿物在火成岩，作为结晶历史的记录。MC-SIMS允许同位素的高空间分辨率分析（在本研究中约为12 μm），因此提高了可以识别结晶条件波动的时间尺度，最终提高了我们对岩浆过程速率的理解。分析了新西兰Okataina火山中心两个主要喷发复合体Tarawera和Haroharo的两个年轻流纹岩矿床中的斜长石晶体。使用MC-SIMS数据与An含量的线性模型以及通过激光烧蚀电感耦合等离子体质谱法（LA-MC-ICP-MS）获得的87 Sr/86 Sr比率对结果进行了基质效应校正。校正后的MC-SIMS Sr同位素比值的平均2σ不确定度为±0.0008/点，在高空间分辨率下，冈田那斜长石的Sr同位素比值是均匀的。平均LA-MC-ICP-MS的斜长石87 Sr/86 Sr比值从两个内破火山岩复合体（Tarawera 87 Sr/86 Sr = 0.7056和Haroharo 87 Sr/86 Sr = 0.7054）建议相似的岩浆来源和相似的同化和分离结晶过程的两个复合体。斜长石的整体均匀性（不包括残余核）表明贡献没有显著变化（即，地壳同化，镁铁质流入）的系统在大多数斜长石晶体生长。此外，斜长石边缘缺乏87 Sr/86 Sr比值波动表明，居民的岩浆和侵入的镁铁质岩浆之间的相互作用，触发喷发主要限于挥发性和热传递。使用适当的标准和分析，这种MC-SIMS方法可以用来检测短寿命的，开放系统的事件在岩浆库中的87 Sr/86 Sr同位素比值的差异是显着的。
We investigated the potential of multi-collector secondary ion mass spectrometry (MC-SIMS) as a tool for obtaining Sr isotopic compositions in plagioclase, a ubiquitous mineral in igneous rocks that serves as a recorder of crystallization history. MC-SIMS allows for high spatial resolution analysis (~12 μm in this study) of isotopes, and therefore improves the temporal scale at which fluctuations in crystallization conditions can be recognized, ultimately improving our understanding of rates of magmatic processes. Plagioclase crystals from two young rhyolitic deposits from two major eruptive complexes, Tarawera and Haroharo, of the Okataina Volcanic Centre in New Zealand were analysed. Results were corrected for matrix effects using linear modelling of MC-SIMS data versus An contents, as well as87Sr/86Sr ratios acquired via laser ablation inductively-coupled plasma mass spectrometry (LA-MC-ICP-MS). Corrected MC-SIMS Sr isotopic ratios had an average 2σ uncertainty of ±0.0008 per spot, and were homogeneous in Okataina plagioclase at high spatial resolutions. Average LA-MC-ICP-MS87Sr/86Sr ratios of plagioclase from both intra-caldera volcanic complexes (Tarawera87Sr/86Sr = 0.7056 and Haroharo87Sr/86Sr = 0.7054) suggest similar magma sources and similar assimilation and fractional crystallization processes for the two complexes. Overall homogeneity of plagioclase (excluding relict cores) indicates no significant changes in contributions (i.e., crustal assimilation, mafic influx) to the system during the majority of plagioclase crystal growth. Furthermore, lack of87Sr/86Sr ratio fluctuations in plagioclase rims suggest interaction between the resident silicic magma and the intruding mafic magma that triggered the eruptions was largely limited to volatile and heat transfer. Using appropriate standards and analysis, this MC-SIMS method can be used to detect short-lived, open-system events in magma reservoirs where differences in87Sr/86Sr isotopic ratios are significant.
登录
查看更多内容
基于耳石核心内的 Sr/Ca 和 87Sr/86Sr 确定幼年奇努克鲑鱼 (Oncorhynchus tshawytscha) 的母体运行时间
DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
Jessica A. Miller;A. Kent
通讯作者：
A. Kent
DOI：
--
发表时间：
2002
期刊：
影响因子：
--
作者：
G. Leonard;J. Cole;I. Nairn;S. Self
通讯作者：
S. Self
~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？
影响因子：
3.5
作者：
I. Nairn;J. W. Hedenquist;P. Villamor;K. Berryman;P. Shane
通讯作者：
P. Shane
离子探针在碳酸盐锶同位素地球化学中的评价及应用
影响因子：
5.3
作者：
R. Exley
通讯作者：
R. Exley
新西兰塔拉威拉火山约公元 1315 年卡哈罗阿喷发事件的流纹岩岩浆过程
影响因子：
2.9
作者：
I. Nairn;P. Shane;J. Cole;G. Leonard;S. Self;N. Pearson
通讯作者：
N. Pearson