Abstract:

Applying the electron microprobe and sulfur isotope analysis methods, the paper makes research into the typomorphism features of the barite of the two samples in the black-rock-series Ni-Mo deposits in Hunan and Guizhou area.The barite chemical component features of Zhongnancun in Zunyi, Guizhou and Ganziping in Zhangjiajie, Hunan are as the following: contents of Cr2O3, NiO, and  SiO2 are relatively high, 0.39%, 0.96%, and 0.65%, respectively; and the content of Al₂O₃ is relatively low, below 0.15%.The Sr/Ba values vary from 0.011 to 0.034.The δ³⁴S  values measured from the samples of Ganziping of Zhangjiajie in Hunan vary from 54.3‰ to 57.4‰.The study of typomorphism features of the barite, such as its composition and isotope, reflects the hydrothermal genesis of the barite.

Key words:  Hunan-Guizhou area, black rock series, barite, typomorphism