接触变质条件下变碳酸岩CO_2释放与定量计算——以郯庐断裂南段肥东县双山为例

THE STUDY OF RELEASING AND QUANTITATIVE CALCULATION OF CO_2 UNDER THE CONTACT METAMORPHOSE EFFECT

为了探讨接触变质带内变碳酸盐岩变质过程CO2 释放的数量和排放CO2的物理、化学及地质条件 ,根据递进变质反应和时间积分流体通量模型 ,定量分析和定量计算了双山地区变碳酸盐岩在接触变质作用中释放CO2 的通量。计算结果得到CO2 的通量值为 0 72 9× 1 0 4 ～ 2 446× 1 0 4 mol cm2 ,CO2 的来源以接触变质反应释放为主 ;CO2 的生成释放与变质程度呈正相关关系。自白云石带至方解石带变质流体中XCO2 不断升高 ,但钙铝榴石带由于岩浆水影响 ,流体通量最高而XCO2 急剧下降。

To discuss that metamorphic carbonate rocks release the amount and ability of CO 2 and CO 2 releasing conditions,CO 2 flux, which metamorphic carbonate rocks release in contact metamorphism, is analyzed and calculated quantitatively on the basis of metamorphic reaction and time integrated fluid flux. The results suggest that the value of CO 2 flux is 0 729×10 4～2 446×10 4 mol/cm 2,CO 2 is provided mainly by contact metamorphic reations. The generation and release of CO 2 are positive correlation with the degree of metamorphism, and X CO 2 in fluids continuously increases form the zone of dolomite to the zone of calcite, but in the zone of essonite, fluid flux is the largest and X CO 2 sharply decreases for the influence of magmatic water.