摘要
土墩铜镍矿床位于东天山黄山—镜儿泉铜镍成矿带的西端,具有较好的铜、镍资源前景。铜镍矿石中主要金属矿物为黄铜矿、磁黄铁矿、镍黄铁矿、磁铁矿以及黄铁矿等。在详细研究土墩铜镍矿床成矿地质背景的基础上,通过对土墩铜镍矿床中浸染状矿石和块状矿石中主要金属矿物进行电子探针原位测试发现,金属矿物中Pt含量较高,范围在490~2 450 g/t之间,平均为1 713 g/t,而Pd含量则较低。进一步研究Pt的赋存形式及矿石中伴生元素Co、Se、Ag、Sb等的元素地球化学特征,结果表明,晚期成矿热液对早期镍黄铁矿和磁黄铁矿的交代使Pt常发生扩散交代作用,这种热液改造作用对贵金属元素的活化和再富集具有重要意义。此外,土墩铜镍矿床中具有高Se含量、较低S/Se比值以及高R因子值的矿段是极有可能形成铂族元素（PGE）的矿化富集带。
The Tudun Cu-Ni deposit is located at the western segment of the Huangshan-Jingerquan Cu-Ni ore belt in Eastern Tian- shan Mountains, and possesses a good potential for prospecting copper and nickel. The major metallic minerals of ores include chalcopyrite, pyrrhotite, pentlandite, magnetite and pyrite. Based on detailed research on the metallogenic geological setting, and previous petrological and geochemical evidence of the Tudun Cu-Ni deposit, this study performed in situ electron probe microanalysis （EPMA） on these metallic minerals from the disseminated ores and massive ores. The EPMA shows that the concentrations of platinum in the ma- jor metallic minerals vary from 490~ 2 450 g/t, averaging 1 713 g/t, and that the concentrations of palladium are low. We further stud- ied the occurrence states of platinum and the element geochemical characteristics of accessory elements including Co, Se, Ag and Sb. The results show that the influence of hydrothermal metasomatism on pentlandite and pyrrhotite is the most likely process that resulted in the diffusive metasomatism of platinum, which is critical to the activation and re-enrichment of noble metals. In addition, the ore blocks with high Se concentrations, low to moderate S/Se values and high R factor are most likely to form PGE mineralization.
出处
《地质学刊》
CAS
2016年第1期85-96,共12页
Journal of Geology
基金
国家自然科学基金面上项目(41272097)
中国地质调查局项目(1212011085466
12120113089300
12120114016601)
中央高校基本科研业务费专项资金(CUG120702)
中国地质大学(武汉)教学实验室开放基金项目(SKJ2014010)联合资助
关键词
铂的赋存形式
热液成矿作用
铜镍矿床
土墩
新疆东天山
occurrence state of platinum
hydrothermal mineralization
Cu-Ni deposit
Tudun
Eastern Tianshan Mountains in Xinjiang
