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云南香格里拉县九龙一带出露的橄榄辉石岩侵位于峨眉山玄武岩,或呈断块夹持于构造破碎带中。岩相学研究发现,单斜辉石环带结构发育,主要为韵律环带和正环带两种,但吉丁和海西失吉地样品的环带规律性不明显。环带微区的探针成分分析及对比研究表明,安南样品的环带为同一碱性-过碱性系列岩浆多次脉冲补给的产物,其高碱度表现为更高的钙含量、更不饱和的硅和更明显的成分环带,离子的类质同象替代方式、Al-Ti含量的指向性以及温压计算结果反映其形成于温度压力较高的环境;吉丁和海西失吉地样品为富碱的拉斑玄武系列经不明显的分异,形成于活动陆缘低温低压的环境,可能为甘孜—理塘结合带的残余产物。
The olivine-pyroxenite, exposed in Jiulong, Shangri-La County, Yunnan, is located in the Emei Shan basalts or is held in a fractured zone by a fault block. The study of petrography shows that the structures of the clinopyroxenes are developed mainly in the prosodic and the normal zones, but the regularity of the zones in the Jidin and Hercynian geotags is not obvious. The analysis and comparison of probes in the zonal microzone showed that the annulus of the Annan sample was the product of multiple pulse replenishment of the same alkaline-overbased magmatic series, and its high alkalinity showed higher calcium content, Saturated silicon and more pronounced zonal annihilates, isomorphism of ions, the orientation of Al-Ti content and the results of temperature and pressure reflect the formation of high temperature and pressure environment. The samples were alkali-enriched tholei basaltic series, which were not obviously differentiated and formed in low-temperature and low-pressure environment of active land margins, possibly as a residual product of the Garze-Litang belt.