大兴安岭地区库仑迪铅锌矿床成矿特征研究

库仑迪铅锌矿为大兴安岭地区近年新发现的矿床,矿体分别赋存于中元古界兴华渡口群矽卡岩和早石炭世闪长岩中,呈脉状受陡倾构造破碎带控制。锆石U-Pb测年龄结果显示,区内闪长岩的结晶年龄为348.3±5.8 Ma,成岩时代为早石炭世。铅同位素Doe模式年龄为138~167Ma,辉钼矿Re-Os同位素年龄为133.4Ma,属晚侏罗世―早白垩世成矿。硫、铅同位素研究表明,成矿物质源区构造环境为造山带环境,主要为幔源物质,以及对老地层中成矿物质的萃取,南矿段矿床成因为中低温热液矿床,北矿段矿床成因为接触交代矿床(矽卡岩型矿床)。结合勘查事实,认为北矿段找矿空间有限,南矿段深部可能有较大的找矿潜力。

Metallogenic characteristics of Kulundi Pb-Zn Deposit in Daxinganling Region

The Kulundi Pb-Zn deposit was recently discovered in the Daxinganling region. The ore bodies of the Kulundi Pb-Zn deposit preserved in the Mesoproterozoic skarn of Xinghuadukou Goup and Early Carboniferous diorite which shown as veins controlled by tectonic fracture zone with steep slope. Analyses of zircon U-Pb dating indicate that the crystallization age of diorite in the studied Kulundi Pb-Zn deposit is 348.3±5.8 Ma, and thus it formed at Early Carboniferous. The model age of lead isotope ranges in 138 Ma and 167 Ma. The Re-Os isotope age of molybdenite is 133.4 Ma indicating that molybdenite formed at Late Jurassic-Early Carboniferous. Results of S and Pb isotope analyses indicate that the tectonic setting of the source region of the metallogenitic substances is orogenic setting which mainly sourced from mantle and partially extracted from metallogenitic substances within ancient strata. The south ore block genetic type belonged to epithermal-mesothermal deposits , The north ore block genetic type belonged to contact metasomatic deposit (skarn type deposit). We therefore propose that deep in the southern section of the Kulundi Pb-Zn deposit show more potential in prospecting ore compared to the northern section of the deposit.