Using the Sr isotope compositions of feldspars and glass to distinguish magma system components and dynamics
Using the Sr isotope compositions of feldspars and glass to distinguish magma system components and dynamics
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DOI：
10.1130/g30758.1
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发表时间：
2010-06
期刊：
影响因子：
5.8
通讯作者：
V. Martin;J. Davidson;D. Morgan;D. Jerram
中科院分区：
文献类型：
--
作者：
V. Martin;J. Davidson;D. Morgan;D. Jerram
岩浆岩的各个组成部分正日益成为深入了解火山系统的目标。在这里，我们展示了使用Sr同位素微采样来区分不同的玻璃和斜长石群体，这些群体代表了每个喷发岩浆批次中成分（液体和晶体）的来源。我们分析了玻璃和斜长石晶体岩芯，以表征来自希腊圣托里尼岛米诺斯旋回浮石坠落单元的晶体产物和寄主液体。利用这种方法，我们确定了在火山喷发和浮石碎屑形成之前相互作用的岩浆成分，使我们能够解释与每次火山喷发相关的岩浆动力学。可以识别出不同程度的复杂性，从相对简单的晶体与玻璃处于同位素平衡的情况，到更复杂的情况，例如形成火山口的大型米诺斯火山喷发，其特征是至少有两种液体成分和三种不同的晶体来源。
The individual components of magmatic rocks are being increasingly targeted to gain insight into volcanic systems. Here we demonstrate the use of Sr isotope microsampling to distinguish distinct populations of glass and plagioclase that represent the sources of components (liquids and crystals) within each erupted magma batch. We analyzed glasses and plagioclase feldspar crystal cores to characterize crystal cargoes and host liquids from pumice-fall units from the Minoan cycle, Santorini, Greece. Using this approach, we identify the magmatic components that interacted prior to eruption and formation of pumice clasts, allowing us to interpret the magma dynamics associated with each eruption. Varying degrees of complexity can be identified, from relatively simple cases where the crystals are in isotopic equilibrium with the glass, to more complex, such as the large caldera-forming Minoan eruption, which is characterized by at least two liquid components and three different crystal provenances.