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对青岛劈石口含地幔橄榄岩包体的超基性煌斑岩的岩相学、岩石地球化学和矿物化学等方面的研究表明,劈石口煌斑岩贫硅(SiO_2=33.72%~36.70%),富碱,富TiO_2(2.08%~2.57%),Mg#=25.23~37.32,SI=21.53~30.14,FL=30.25~40.64,DI=16.4~31.1,均显示煌斑岩岩浆演化程度不高,与玄武安山岩类相当;明显富集大离子亲石元素和轻稀土,相对亏损高场强元素,轻重稀土分异明显,微量元素配分模式和比值指示煌斑岩与OIB相似,具有明显的Cr、Ni负异常而Eu负异常不明显,Nb*值大于1,Nb/U=30.32~41.04,说明煌斑岩具有富集地幔源区特征,岩浆上升过程中没有受到明显的陆壳物质的混染,主要进行了以橄榄石和单斜辉石为主的分离结晶作用。劈石口煌斑岩富集地幔源区的形成可能与中生代中国东部软流圈的上涌有关,华北克拉通岩石圈拉张减薄,形成造山后期拉张环境是引起富集地幔部分熔融和煌斑岩岩浆侵位的原因。
Studies on lithofacies, lithochemistry and mineral chemistry of the ultrabasic lamprophyres of the mafic peridotite inclusions in the Cleateikou, Qingdao show that the petrological porphyry in the Miocene is poor silicon (SiO_2 = 33.72% ~ 36.70%), , Rich in alkali, rich in TiO_2 (2.08% ~ 2.57%), Mg # = 25.23 ~ 37.32, SI = 21.53 ~ 30.14, FL = 30.25 ~ 40.64, DI = 16.4 ~ 31.1, Which is similar to the basaltic andesite. The enrichment of large ion lithophile and light rare earth, relatively depleted high field strength elements, obvious difference of light and heavy rare earths, trace element distribution patterns and ratios indicate that the lamprophyres are similar to OIB and have obvious Cr, Ni negative anomaly and negative Eu anomaly, Nb * value greater than 1, Nb / U = 30.32 ~ 41.04, indicating that the lamprophyre is rich in mantle source characteristics of the magma did not rise during the apparent contamination by the continental crust material , The main olivine and clinopyroxene-based crystallization of the role of separation. The formation of enriched mantle source area of the lamphelite porphyry may be related to the upwelling of the asthenosphere in the eastern China in the Mesozoic. The lithosphere of the North China craton thintens and the extensional environment of the late orogeny is caused by partial melting of the enriched mantle Causes of porphyry magma emplacement.