湘东长沙 -澧陵 -浏阳一带中晚元古宇的冷家溪群及板溪群遭受了区域甚低级变质作用。在本地区所采的 <2μm的样品中 ,冷家溪群伊利石结晶度的 Kübler指数为 0 .18～ 0 .2 6°△ 2θ,板溪群为 0 .2 1～ 0 .2 8°△ 2θ(Kisch国际标样校正 )。从而可把本地区冷家溪群的区域变质划归浅变质带和近变质带上部 ,温度大约为 2 80～ 40 0℃。板溪群划归近变质带上部 ,温度大约为 2 5 0～ 30 0℃。并未普遍达到目前人们认为的绿片岩相或者是低绿片岩相。样品中冷家溪群伊利石 (白云母 ) b0 值的范围在0 .8999～ 0 .90 42 nm ,板溪群为 0 .90 18～ 0 .90 42 nm。由冷家溪群 b0 频率累积曲线图 ,得出本区冷家溪群处于较典型的中压区 The Lengjiaxi Group and Banxi Group in Middle-Late Proterozoic from Changsha-Shaoling-Liuyang area suffered very low-level metamorphism in the region. In the samples of <2μm collected in this area, the Kübler index of the illite crystallinity of Lengjiaxi group is 0.18 ~ 0.226 ° △ 2θ, and the Banxi group is 0.21 ~ 0.28 ° △ 2θ (Kisch International Standard Calibration). Thus, the area of ​​Lengjiaxi Group in this area can be classified as metamorphic zone and upper metamorphic zone, and the temperature is about 280 ~ 400 ℃. Banxi group was assigned to the upper metamorphic belt, the temperature is about 250 ~ 30 0 ℃. The greenschist facies, or the low-greenschist facies, are not universally found at present. The range of b0 values ​​for the Lengjiaxi group illite (muscovite) in the sample ranged from 0.08999 to 0.090 42 nm, and Banxi group was 0.090 18 to 0.90 42 nm. From cold Jiaxi group b0 cumulative frequency curve, drawn in this area Leng Jiaxi group in a more typical medium pressure area