江西相山南部花岗斑岩中绿泥石特征及其形成环境研究

Characteristics of Chlorite and its Forming Environment in the Granitoid Porphyry of Southern of Xiangshan

绿泥石化是铀成矿作用过程中的一种重要的蚀变类型,针对采自相山南部地区的花岗斑岩岩石样品研究发现,绿泥石化是这一花岗斑岩中常见的热液蚀变现象。选择相山南部地区花岗斑岩中绿泥石进行岩相学和电子探针成分分析研究,测定各个地区花岗斑岩中绿泥石的化学成分,计算了绿泥石中Al~Ⅳ、Al~Ⅵ、n(Al)/n(Al+Mg+Fe)及n(Al~Ⅵ+Fe~Ⅱ)-n(Mg)等相关指数及其形成温度。讨论绿泥石特征及其形成环境。研究表明:1)相山南部花岗斑岩中绿泥石主要由黑云母蚀变而来,绿泥石主要为蠕绿泥石和铁镁绿泥石,少数属于鲕绿泥石;2)相山南部上南地区花岗斑岩中绿泥石主要来源于铁镁质岩石或富铁、镁的流体,而下堡地区主要来源为泥质岩;3)南部花岗斑岩中绿泥石的形成温度变化于217.91~278.45℃之间,平均温度256.09℃。

Chloritization is an important alteration type in the process of uranium mineralization and metallogenesis. The study of granite - porphyry rock samples from the southern part of the Xiangshan area, It is found that chloritization is a common hydrothermal alteration phenomenon in this granite porphyry. In this paper, Based on EPMA anaalysis and mineralogical study of the chlorite from the granite porphyry in the southern part of Xiangshan area. The chemical composition of chlorite in granite porphyry in each area was determined. The correlation coefficient of the Al^Ⅳ、Al^Ⅵ, n （Al）/n （ Al ＋ Mg ＋ Fe）, n （ Al^Ⅳ ＋ Fe ^Ⅳ ） - n （Mg） and the formation temperature of chlorite were calculated. And the characteristics of chlorite and its forming environment were discussed. 1 ） The chlorite in the granitic porphyry of southern Xiangshan is mainly altered by biotite,and the chlorite in the granite porphyry is mainly composed of bmnsvigite and ripidolite, a few belong to chamosite. 2） The chlorite from the granite porphy-7 in the ShangNan area of Xiangshan is mainly derived from ferromagnesitic rocks or iron-rich and magnesium-rich fluids, while the main sources of the granite porphyry are mudstone in the XiaBao area. 3） The formation temperature, of chlorite in the granite porphyry in the south is between 217.91 -278.45 ℃ ,the average temperature is 256.09 ℃.