JIANG Xin1, CHEN Yuan-rong1,2*, LIU Yi-zhi1, GU Rui-qi1, LI Ruo-jian1, LI Jia-cai1, NONG Yue-jin1, BAI Yu-hang1, ZHANG Zong-wei1, XU Fang1
(1. College of Earth Sciences, Guilin University of Technology, Guilin 541004, China;
2. Engineering Research Center of Exploration for Hidden Non-ferrous and Precious Metal Ore Deposits, Guilin University of Technology, Guilin 541004, China)
Abstract: The No. I ore body of the Jiaojia Gold Mine in Shandong Province is taken as the research object in this paper. Rock samples of different geological bodies around gold ore body on the Line 128 are selected for analyzing the suspected carbonate minerals in samples using methods of rock and mineral identification, laser Raman analysis and electron probe analysis, to study the occurrence characteristics of hydrocarbon gases at mineral scale in order to obtain direct evidence of the hydrocarbon gas involvement in mineralization. It has been found that compositions of suspected carbonate minerals in samples analyzed using EPMA are coincided with that of pure calcite. In different geological bodies around the gold ore body, calcite occurred as very fine particles filling in mineral fissures or as veinlets filling in pores between mineral particles, indicating characteristics of later stage formation. In addition, contents of the hydrocarbon gas obtained by using EPMA analysis are generally consistent with those obtained by using the acid-hydrolyzed hydrocarbon method. The hydrocarbon gas has characteristics of outward infiltration and diffusion. This study has confirmed that the suspected carbonate minerals in samples are indeed carbonate minerals which had provided carriers for hosting hydrocarbon gases. The direct evidence for the involvement of hydrocarbon gases in the gold mineralization at mineral scale has been found. At the same time, it is proved that the acid-hydrolyzed hydrocarbon method can be used to effectively extract hydrocarbon gas information related to the gold mineralization and can be certainly used for guiding the exploration of metal deposits.
Keywords: At mineral scale; Electron Probe; hydrocarbon gas; occurrence; carbonate minerals; the Jiaojia gold deposit
ACTA MINERALOGICA SINICA Vol. 39, No.3, 2019, page 264-270
