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从矿物学和主微量元素地球化学的角度对香格里拉洛吉玄武岩进行研究。该玄武岩的w(SiO2)为45.08%～50.50%,w(MgO)为2.86%～14.73%,w(Na2O+K2O)为1.78%～6.34%,且Na2O>K2O,属于碱性玄武岩系列;相对富集轻稀土而亏损重稀土(LREE/HREE=1.88～9.61),轻重稀土发生了一定程度的分异,没有明显的Eu异常(δEu=0.91～1.10),富集大离子亲石元素(Rb,Ba,Sr,Pb),相对亏损高场强元素(Nb,Ta,Zr,Hf),且表现出Pb的强烈富集,Ba和Sr元素有明显的波动。研究表明,该玄武岩为富集岩石圈地幔石榴石+尖晶石二辉橄榄岩5%～20%部分熔融的产物,形成于板块汇聚边缘的构造环境,在成岩的过程中不存在明显的地壳混染,并且发生了橄榄石、单斜辉石、磷灰石、金红石的分离结晶作用。
The Shangri-Laji rock basalt is studied from the perspective of mineralogy and major trace element geochemistry. The basalt has a w (SiO2) of 45.08% to 50.50%, a w (MgO) of 2.86% to 14.73%, a w of (Na2O + K2O) of 1.78% to 6.34% and a Na2O> (LREE / HREE = 1.88 ~ 9.61), some differences occur between light and heavy rare earths, and there is no obvious Eu anomaly (δEu = 0.91 ~ 1.10). The enrichment of large ion lithophile , Ba, Sr, Pb), relative depletion of high field strength elements (Nb, Ta, Zr, Hf), and strong Pb enrichment, with significant fluctuations of Ba and Sr. The study shows that the basalt is a partial melting product enriched in 5% ~ 20% of lithospheric mantle garnet + spinel lherzolites and formed in the tectonic setting margin of plate convergence. There is no obvious crustal contamination during diagenesis , And the crystallization of olivine, clinopyroxene, apatite and rutile occurred.