松辽盆地东北缘孙家窑地区碳酸盐岩接触变质带元素分配关系和CO_2定量释放  

THE ELEMENT DISTRIBTUING RELATION AND THE ABILITY OF CO_2 RELEASED OF CARBONATE CONTACT METAMORPHIC BELTS IN SUNJIAYAO AREA, THE NORTHEAST EDGE OF THE SONGLIAO BASIN

作　　者：李振生[1] 刘德良[1] 杨晓勇[1] 谈迎[1] 杨强[1] 王伯长[2] 郑德山[2] 王凤来[2] 孙占强[2] 

机构地区：[1]中国科学技术大学地球与空间科学学院,安徽合肥230026 [2]大庆油田有限责任公司,黑龙江大庆163453

出　　处：《天然气地球科学》2004年第1期20-27,共8页Natural Gas Geoscience

基　　金：国家重点基础研究发展规划项目(编号:2001CB209132);国家自然科学基金重大项目(编号:49794044)资助.

摘　　要：为了定量分析碳酸盐岩接触变质作用形成的CO2,研究了松辽盆地东北缘碳酸盐岩接触变质带常量元素和稀土元素的元素分配关系。认为碳酸盐岩接触变质过程中主要体现为硅的富集和钙、碳的亏损,并且CaO、SiO2与ΣREE呈线性关系;随着变质程度增高,元素的含量、稀土元素的分布型式和分馏程度越趋向花岗岩,其主要原因是碳酸盐岩与侵入流体的混染作用、碳酸盐岩硅化及矿化过程引起的稀土变化、碳酸盐岩重结晶对轻稀土元素的富集。计算得出了CO2释放量与岩石体积比(2.7～256.7)。证明了碳酸盐岩接触变质作用是无机成因CO2形成的机制。To provide quantitative evidence, that dioxide carbon is released in carbonate contact metamorphism, the distributing relation of main and rare earth elements and the quantity of CO_(2) released in carbonate contact metamorphic belts are researched in the northeast edge of Songliao basin. The most characters are the enrichment of silicon and the loss of carbon and calcium, and there is a linear relation among CaO, SiO_(2) and ΣREE. The element content and the REE pattern more tend to that of granite with the metamorphic degree deeper. The reasons, which cause those, are mixture of carbonate and fluid, the variety of REE in silification and mineralization of carbonate and the enrichment of light REE in carbonate recrystallization. The volume ratio of the amount of dioxide carbon released and the rock is from 2.7 to 256.7, which prove that inorganic CO_(2)that is released in carbonate contact metamorphism is a potent gas source.

关 键 词：接触变质作用 碳酸盐岩 递进变质反应式 元素迁移 

分 类 号：P588.31[天文地球—岩石学]