Magnesite-Dolomite Equilibrium in Fluids Between 100 and 200oC

本文描述了在100 ~ 200℃温度范围内研究菱镁矿-白云石平衡的三年研究计划。在Na-Mg-Ca-Cl盐水中进行一到四个月的脱白云化实验，在“有序”化学计量白云石溶解后，通过菱镁矿沉淀达到平衡。在Stoessell等人（1987）进行的为期7周的脱白云化实验中，实验程序已成功地进行了测试，在该实验中，方解石-白云石平衡在相同的温度范围内接近。反应后的固体将用x射线衍射技术、岩相显微镜、扫描电子显微镜和电子探针进行检查。该研究的数据将填补100至200℃范围内白云石-菱镁矿平衡的实验空白。研究结果将(1)有助于确定白云石-菱镁矿平衡边界的位置；(2)有助于确定白云石的稳定场。

This proposal describes a three year research program to study magnesite-dolomite equilbria in the temperature range of 100 to 200oC. One to four month dedolomitization experiments will be run in Na-Mg-Ca-Cl brines in which equilibrium is approached by magnesite precipitation, following dissolution of "ordered" stoichiometric dolomite. The experimental procedure has been successfully tested in the seven week dedolomitization experiments of Stoessell et. al. (1987) in which calcite-dolomite equilibria was approached over the same temperature range. The reacted solids will be examined with X-ray diffraction techniques, petrographic microscopy, scanning electron microscopy, and by an electron microprobe. Data from the study will fill in the experimental gap on dolomite-magnesite equilibria in the 100 to 200oC range. The results will (1) help resolve the location of the dolomite-magnesite equilibrium boundary and (2) help define the stablity field of dolomite.