Zircon saturation in terrestrial basaltic melts and its geological implications
Zircon saturation in terrestrial basaltic melts and its geological implications
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陆相玄武岩熔体中的锆石饱和度及其地质意义
DOI：
10.1016/j.sesci.2018.08.001
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发表时间：
2019-03
影响因子：
2
通讯作者：
Maoshuang Song
中科院分区：
文献类型：
--
作者：
Tongbin Shao;Ying Xia;Xing Ding;Yongfeng Cai;Maoshuang Song
锆石是一种用途广泛的副矿物，硅酸盐熔体中锆石的饱和度在地质学中有着广泛的应用。基于沃森和哈里森提出的原始模型（地球行星。Sci. Lett. 64：295-304，1983），在具有长英质和中间组成的熔体中锆石饱和度的定量最近已成为主要的研究课题，导致一些分歧和不同的模型。从理论上讲，增加新的数据，特别是关于玄武岩（过碱性）熔体中锆石溶解度的数据，可以提供一个上限，低于该上限，锆石可能会在火成岩中结晶，因此对于开发新的、改进的模型至关重要，该模型可应用于广泛的成分，并为正在进行的争论提供解决方案。本文首次利用活塞-圆筒装置在1050-1350 °C温度范围内，在0.5，1.0和1.5GPa压力下，系统地研究了玄武岩熔体中锆石的饱和度。我们结合我们的新数据，从以前的研究数据，镁铁质长英质熔体镁铁质熔体的玄武岩熔体中的锆石饱和度的影响因素进行调查。我们的研究结果证实了极高的锆石饱和度在镁铁质（过碱性）熔体除了其强烈的熔体成分和温度的依赖性和其弱的压力和水含量的依赖性。我们使用了所有可用的数据，可以用来计算组成参数G [=（3·Al2O3+ SiO2）/（Na 2 O + K2 O + CaO + MgO + FeO），摩尔比]，以评估与先前设计用于更碱性组合物的模型的拟合，并提出了新的改进模型，由下式给出：（误差为1σ）：lnCZr（熔体）=（3.313 ± 0.349）-（1.35 ± 0.10）·lnG+（0.0065 ± 0.0003）·T，其中CZr（熔体）为锆石饱和时熔体中的Zr浓度，T为温度，单位为℃。此外，我们重新引入了先前提出的温度和熔体组合物对聚合度的主导地位，从而锆石进入熔体的能力，从而导致中间长英质岩浆和镁铁质岩浆之间的锆石饱和度的巨大差异。虽然幔源玄武岩浆的锆含量较低，但它们在上升过程中能够溶解周围岩石中的锆石。锆石在喷出或浅成玄武岩中一般很少，但可在深成玄武岩岩浆结晶晚期形成，因此，锆石结晶对镁铁质岩浆中微量元素的分布几乎没有影响。
Zircon is a widely used accessary mineral, and zircon saturation in silicate melts has many applications in geology. Based on the original model proposed by Watson and Harrison (Earth Planet. Sci. Lett. 64:295–304, 1983), the quantification of the zircon saturation in melts with felsic and intermediate compositions has recently become a major research topic, resulting in some disagreements and different models. Theoretically, the addition of new data, especially regarding the zircon solubility in a basaltic (peralkaline) melt that can provide an upper limit below which zircon is likely to crystallize in igneous rocks, is thus critical to the development of a new, refined model that can be applied to a wide range of compositions and provide a resolution to the ongoing debate. Here, the zircon saturation in a terrestrial basaltic melt was systematically investigated for the first time using a piston-cylinder apparatus across the temperature range of 1050–1350 °C at pressures of 0.5, 1.0 and 1.5 GPa. We combined our new data on mafic melts with data from previous studies on mafic to felsic melts to investigate the factors affecting zircon saturation in basaltic melts. Our results confirm an extremely high zircon saturation in mafic (peralkaline) melts in addition to its strong dependence on the melt composition and temperature and its weak dependence on the pressure and water content. We used all available data that can be used to calculate compositional parameter G [=(3·Al2O3+ SiO2)/(Na2O + K2O + CaO + MgO + FeO), molar ratio] to evaluate fit to a previous model designed to work with more alkaline compositions and proposed a new refined model, given by (with 1σ errors): lnCZr(melt) = (3.313 ± 0.349)–(1.35 ± 0.10)·lnG+ (0.0065 ± 0.0003)·T, whereCZr(melt) is the Zr concentration in the melt at zircon saturation andTis temperature in °C. Additionally, we reintroduced the previously proposed dominance of the temperature and melt composition on the degree of polymerization and thus the ability of zircon to enter the melt, thereby leading to large differences in the zircon saturation between intermediate-felsic magmas and mafic magmas. Although mantle-derived basaltic magmas have a low Zr concentration, they are capable of dissolving the zircon in surrounding rocks during their ascent. Zircons are generally rare in extrusive or hypabyssal basaltic rocks but can form during the late crystallization stage of plutonic basaltic magmas; thus, zircon crystallization has little impact on the distribution of trace elements in mafic magmas.
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DOI：
10.1007/978-3-540-72816-0_23774
发表时间：
2019-11
期刊：
Dictionary of Geotourism
影响因子：
--
作者：
I. S. Williams
通讯作者：
I. S. Williams
海南岛下古生界地层碎屑锆石U-Pb年代学和Hf同位素：华南东南部早期地壳演化的新线索
影响因子：
6.1
作者：
Zhou Y;Liang X Q;Liang X R;Jiang Y;Wang C;Fu J G;Shao T B
通讯作者：
Shao T B
影响因子：
3.5
作者：
G. Vavra;R. Schmid;D. Gebauer
通讯作者：
G. Vavra;R. Schmid;D. Gebauer
影响因子：
3.5
作者：
Belousova, EA;Griffin, WL;Fisher, NI
通讯作者：
Fisher, NI
影响因子：
3.9
作者：
Boehnke, Patrick;Watson, E. Bruce;Schmitt, Axel K.
通讯作者：
Schmitt, Axel K.