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本文提供了冀东迁西地区早太古代麻粒岩辉石、石榴石、角闪石和黑云母的大量新的湿化学分析结果。详细地讨论了共存铁镁矿物之间铁和镁的分配系数。辉石对的K_(D(Fe))值变化不大以及在Wo-En结上的交点十分接近,暗示达到了均一的平衡条件。根据岩相学观察和各种地质温度计和地质压力计的计算,在遭受地热梯度为18—23℃/公里的中压麻粒岩相变质作用时,麻粒岩变质重结晶的P-T条件是11—13千巴和800—850℃。
This paper provides a large number of new wet chemical analysis results of the early Archaean granulite pyroxene, garnet, hornblende and biotite in the western Qianxi area. The distribution coefficients of iron and magnesium between co-existing iron-magnesium minerals are discussed in detail. The change of K_ (D (Fe)) value of pyroxene pair and the intersection point on Wo-En junction are very close, implying that a uniform equilibrium condition is reached. According to petrographic observation and calculation of various geothermometers and geostatometers, the PT conditions for the metamorphic recrystallization of granulite are as follows: when subjected to medium-pressure granulite facies metamorphism with a geothermal gradient of 18-23 ° C / km -13 kPa and 800-850 ° C.