An apatite for progress: Inclusions in zircon and titanite constrain petrogenesis and provenance
An apatite for progress: Inclusions in zircon and titanite constrain petrogenesis and provenance
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DOI：
10.1130/g37301.1
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发表时间：
2016-02
期刊：
影响因子：
5.8
通讯作者：
E. Bruand;C. Storey;M. Fowler
中科院分区：
文献类型：
--
作者：
E. Bruand;C. Storey;M. Fowler
磷灰石作为一种在地球和行星科学中有许多用途的矿物，最近得到了相当大的关注。磷灰石化学最近给了新的见解，广泛的地质过程和工具，如岩浆作用，交代作用，行星地球化学和地质年代学。我们在这里提出了一种新的方法来指纹岩浆化学和岩石成因中使用磷灰石包裹体强大的钛铁矿和锆石扩大磷灰石的效用。我们目前的微量元素数据从磷灰石矿物包裹体屏蔽在岩浆锆石和钛铁矿。重要的是，磷灰石夹杂物和主机钛酸盐化学在这项研究中详细允许估计全岩Sr和SiO2。我们展示了如何使用这些数据来评估寄主岩浆的分馏程度，并计算关键的微量元素丰度和比值。我们证明，包裹体可以链接到离散的时期，在结晶历史的主机阶段，从而提供深入了解岩石成因。结果强调，磷灰石组合物可能区分现代花岗岩类（年龄小于2.5 Ga）从太古代-元古代过渡花岗岩类组合物（sanukitoid签名）。这种岩石学工具的发展具有重要的潜力，解释的起源和更好地了解大陆地壳的长期演变，包括早期地球。
Apatite has recently gained considerable attention as a mineral with many uses within the Earth and planetary sciences. Apatite chemistry has recently given new insight into a wide range of geological processes and tools, for example, magmatism, metasomatism, planetary geochemistry, and geochronology. We expand the utility of apatite here by presenting a novel way to fingerprint magma chemistry and petrogenesis using apatite inclusions within robust titanite and zircon. We present trace element data from apatite mineral inclusions shielded within magmatic zircon and titanite. Importantly, apatite inclusion and host titanite chemistries detailed in this study allow estimation of the whole-rock Sr and SiO2. We show how these data can be used to assess the degree of fractionation of the host magma and to calculate key trace element abundances and ratios. We demonstrate that the inclusions can be linked to discrete periods in the crystallization history of the host phases, thus providing insight into petrogenesis. The results highlight that apatite compositions might discriminate modern granitoids (younger than 2.5 Ga) from Archean–Proterozoic transitional granitoid compositions (sanukitoid signatures). Development of such a petrological tool has important potential for interpretation of provenance and a better understanding of the secular evolution of the continental crust, including that of early Earth.