摘要
辽南５０号金伯利岩管金刚石的包裹体类型一直被认为是以超镁铁岩组合为主。最近，在同一岩管中发现一颗金刚石中有两种组合类型矿物共生：橄榄石，为超镁铁岩型；石榴石，绿辉石，为榴辉岩型组合。化学成分分析还表明，同一矿物的不同颗粒化学成分没有明显变化。根据石榴石与绿辉石的共生组合关系，钙、镁和铁之间的交换，计算其平衡温度为１２０３℃，压力为５×１０￣９Ｐａ。超镁铁岩与榴辉岩包裹体共生，表明该金刚石成生环境的复杂性。很可能是地幔动力学过程或者是幔源岩浆多期多相导致金刚石成生环境的迅速变化。
It is considered that the diamond inclusion of No. 50 Kimberlite pipe in the southern ofLiaoning take assemblage of ultramafic rock as the principal thing,but recently there are twokinds of dineral paragenesis composite discovered in a diamond of the same Kimberlite pipe:olivinea type of ultramafic rock;garnet and omphacite-a assemblage type of eclogite. Chem-ical composition analysis show that there is no distinct changes in the chemical compositionof different grains in the same mineral. The equirlibrium temperature is estimated at 1203℃,the pressure is 5 ×10￣9Pa among the exchange of Ca,Mg and Fe, according to the associationof garnet and omphacite. Paragenesis of ultramafic rock and eclogite inclusions show that theformed environment of the diamond is very complex. It is possible to cause the rapid changeof the formed environment of diamond under the dynamic process of mantle or multiple phaseand polyphase mantle-derived magma.
关键词
金刚石
超镁铁岩
榴辉岩
矿物包裹体
The southern of Liaoning Diamond Ultramafic rock Eclogitye Paragenesis
