Zircon trace element constrains on the link between volcanism and plutonism in SE China
Zircon trace element constrains on the link between volcanism and plutonism in SE China
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锆石微量元素对中国东南部火山作用与岩成作用联系的制约
DOI：
10.1016/j.lithos.2018.08.040
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发表时间：
2018-11
期刊：
影响因子：
3.5
通讯作者：
Reiner Klemd
中科院分区：
文献类型：
--
作者：
Li Li Yan;Zhen Yu He;Christoph Beier;Reiner Klemd
火成岩锆石晶体中的微量元素在单晶或晶体群体中是可变的，对熔体成分的变化特别敏感。在这项研究中，我们提供了来自中国东南雁荡山破火山口杂岩的火山岩和深成岩中的锆石微量元素数据。喷发的流纹岩被解释为最具分异的岩浆，而侵入的斑岩石英正长岩被认为是残余晶体碎屑的代表。两种岩性的锆石晶体根据其内部结构可分为两种类型：A型晶体具有明显的振荡生长分带，B型晶体具有明亮的阴极发光(CL-BIG亮)。B型锆石以A型锆石边缘或单个颗粒的形式赋存。与A型锆石相比，B型锆石通常具有较低的Hf、U、Th和Y含量，较高的Ti、Zr/Hf和Eu/Eu*比值。火山岩样品的锆石微量元素组成一般与同时含有A型和B型锆石的火山岩内斑状石英正长岩和镁铁质微粒包体的锆石微量元素组成相重叠。尽管总体上存在重叠，但火山岩中的锆石颗粒表现出相对较高的Hf含量和Y/Dy比值，较低的Ti含量和Th/U比值，以及较大的Eu负异常。我们认为，锆石晶体的晶间和晶内成分变异性可以用来追踪岩浆系统的演化。结果表明，在同一岩浆系统中，火山岩和深成岩在岩浆演化过程中不断结晶，这些岩石的岩浆可能通过分离结晶联系在一起。此外，B型锆石颗粒在相对较热和较少演化的岩浆中结晶，表明发生了岩浆补充事件。因此，火成岩锆石晶体的地球化学变异性可以用来推断单个火山岩系的岩浆演化，这可能也适用于其他地球动力学环境。
Trace elements in igneous zircon crystals are variable within single crystals or amongst populations of crystals and are particularly sensitive to changes in melt composition. In this study, we present zircon trace element data from both volcanic and plutonic rocks of the Yandangshan caldera complex from SEChina. The erupted rhyolitic rocks are interpreted to represent the most differentiated magma, whereas the intruded porphyritic quartz syenites are thought to be representative of the residual crystal mush. The zircon crystals of both lithologies are subdivided into two types based on their internal structures: type A with a distinct oscillatory growth zoning and type B crystals are bright in cathodoluminescence (CL-bright). Type B zircon occurs as rims of type A zircon or as individual grains. Compared to type A, type B zircons commonly show lower Hf, U, Th and Y concentrations and higher Ti and Zr/Hf and Eu/Eu* ratios. The zircon trace element compositions of the volcanic samples generally overlap those of the intracaldera porphyritic quartz syenite and mafic microgranular enclaves that contain both type A and type B zircons. Despite a general overlap, zircon grains from the volcanic rocks show relatively higher Hf contents and Y/Dy ratios, lower Ti contents and Th/U ratios and larger negative Eu anomalies than the plutonic samples. We suggest that the inter- and intragrain compositional variability of zircon crystals can be used to track the evolution of magmatic systems. We show that in our case, the volcanic and plutonic rocks crystallized continuously during the magmatic evolution in a common magma system and that the magmas of these rocks may be linked by fractional crystallization. Furthermore, the type B zircon grains are inferred to have crystalized in relatively hot and less evolved magma indicating a magma recharge event. Consequently, the geochemical variability of igneous zircon crystals can be used to infer on the magmatic evolution of single volcanic system which may also be applicable in other geodynamic environments.
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影响因子：
3.9
作者：
Zhenyu He;Xi‐sheng Xu
通讯作者：
Zhenyu He;Xi‐sheng Xu
影响因子：
3.5
作者：
Lili Yan;Zhengjun He;C. Beier;R. Klemd
通讯作者：
Lili Yan;Zhengjun He;C. Beier;R. Klemd
影响因子：
2.5
作者：
A. Barth;A. D. G. Feilen;S. Yager;S. Douglas;J. Wooden;N. Riggs;J. Walker
通讯作者：
A. Barth;A. D. G. Feilen;S. Yager;S. Douglas;J. Wooden;N. Riggs;J. Walker
影响因子：
3.9
作者：
T. Günther;R. Klemd;X. Zhang;I. Horn;S. Weyer
通讯作者：
T. Günther;R. Klemd;X. Zhang;I. Horn;S. Weyer
影响因子：
3.1
作者：
Xinmin Zhou;T. Sun;W. Shen;L. Shu;Y. Niu
通讯作者：
Xinmin Zhou;T. Sun;W. Shen;L. Shu;Y. Niu