The use of apatite as a record of initial 87Sr / 86Sr ratios and indicator of magma processes in the Inagawa pluton, Ryoke belt, Japan
The use of apatite as a record of initial 87Sr / 86Sr ratios and indicator of magma processes in the Inagawa pluton, Ryoke belt, Japan
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DOI：
10.1016/j.chemgeo.2005.05.001
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发表时间：
2005-10
期刊：
影响因子：
3.9
通讯作者：
M. Tsuboi
中科院分区：
文献类型：
--
作者：
M. Tsuboi
日本西南部稻川岩体中磷灰石的Sr同位素分析揭示了该岩体中初始87 Sr/86 Sr（SrI）的空间分布，其分辨率是前所未有的。虽然旧单位的SrI值显示出最大的变化（0.7093-0.7107），但新单位的SrI值相对均匀，约为0.7096。较老的单元还包含大量的镁铁质微粒包体，这是缺乏在年轻的单位。将这些结果与大块岩石分析和野外观察相结合，表明稻川岩体中岩石学和大块化学的广泛变化并不完全是由于以前认为的分离结晶。镁铁质和长英质熔体之间的混合也起了重要作用。在年轻的单位缺乏飞地和均匀的SrI值表明，混合完成了这个时候。
Sr isotopic analysis of apatite in the extensive Inagawa pluton of southwestern Japan reveals the spatial distribution of initial87Sr/86Sr (SrI) within this body with an unprecedented resolution. While the SrI values in older units show the largest variation (0.7093–0.7107), the younger ones have relatively homogeneous SrI values around 0.7096. The older units also contain numerous mafic microgranular enclaves, which are absent in the younger units. Combining these results with bulk rock analyses and field observations suggests the wide variation in petrology and bulk chemistry in the Inagawa pluton is not solely due to fractional crystallization as previously thought. Mixing between mafic and felsic melts has also played a significant role. The lack of enclaves and homogeneous SrI values in the younger units suggest that mixing was complete by this time.