摘要
金伯利岩和钾镁煌斑岩中与地幔流体有关的矿物可分为3类:①超深流体传输矿物:金刚石和寄主岩中的自然元素,它们很可能是地核组分,所代表的流体来自核幔边界,以无氧或缺氧为特征;②深部流体交代矿物:富含K、Na、Ti、Ba和Fe^(3+)等地幔流体特征成分,显示富氧特征,并经历了变质变形作用,该流体与超深缺氧流体的分界面为方铁矿稳定部位;③地幔流体改造矿物:地幔岩造岩矿物被流体改造而含水或含过量水,直至橄榄石蛇纹石化而终止,地幔流体为富水碱性流体。根据地幔交代作用的产物可以反演地幔流体的特点。
This paper focus on the deduction of main characteristics of mantle fluids based on the product of mantle metasomatism. Minerals related to mantle fluids in kimberlite and lamproite can be devided into three types: Ultradeep fluid transmission minerals:natural elements in diamonds and diamond-bearing rocks. They possibly belong to the core component and representative of fluids coming from the core-mantle boundary and is characterized by absence or lack of oxygen. Deep fluid metasomatic minerals:minerals that have undergone metamorphism and deformation and are rich in typical elements of mantle fluids, i. e. K, Na, Ti, Ba and Fe^(3+) , showing enrichment of oxygen. The demarcating plane between ultradeep fluid and deep fluid is the stable plane of wuestite. Mantle-fluid reformed minerals:rock-forming minerals of mantle peridotites were reformed by mantle fluid to result in excessive water until olivine was entirely changed into serpentine. The mantle fluid is waterrich alkaline fluid.
出处
《地质论评》
CAS
CSCD
北大核心
2002年第S1期279-282,共4页
Geological Review
基金
国家自然科学基金(编号49973013)资助的成果
