摘要
海沟金矿为一大型贫硫化物石英脉型金矿床,长期以来其形成时代一直存在争议,致使矿床成因研究受到较大影响,成矿预测等方面研究进展缓慢。采用石英流体包裹体的40Ar/39Ar激光探针定年法对该金矿床进行了精细的年代学测定,获得主成矿阶段石英流体包裹体的40Ar/39Ar正、反等时线年龄分别为(170±20)Ma和(172±16)Ma,MS WD分别为0.31和0.35,40Ar/36Ar比值分别为298±4和299±4;进一步剔除接近大气的成分点和过剩氩高的成分点,计算获得等时线年龄为(170±38)Ma(40Ar/36ArInt.=299±10)和(165±52)Ma(40Ar/36ArInt.=303±23)。结合已有同位素年代学研究成果,进一步明确了海沟金矿床主成矿期发生在早侏罗世晚期,成矿作用与中生代库拉板块向亚洲板块俯冲、特别是由此引发的华北板块东缘与兴蒙造山带东段的强烈拼贴并诱发的岩石圈加厚、减薄作用密切相关。
There are diverse metallogenic ages of Haigou gold deposit, a large low-sulfide quartz vein type gold deposit, which restrict studying on genesis and ore prospecting of it. With 40Ar/39Ar laser probe dating of fluid inclusions in quartzs, the authors present an isochron 40Ar/39Ar age （170±20） Ma （MSWD=0.31）and an inverse one （172±16） Ma （MSWD=0.35） of fluid inclusions in quartzS formed in major metallogenetic stage, and 40Ar/36Ar ratios are 298±4 and 299 ± 4 respectively. Eliminating some data with high superfluous Ar and those close to atmosphere, the authors get an isochron age （170±38） Ma （40Ar/36Ar Int.=299±10） and an inverse one （165±52） Ma （40Ar/36Ar Int.=303±23）, respectively.It’s clear that Haigou deposit formed in Late Early Jurassic, combing with published isotopic geochronologies. Gold mineralization is closely related to subduction of the Kula plate under the ancient Asian plate in Mesozoic, particularly to the intensive convergence between the eastern North China plate and the eastern margin of the Xing’an-Mongolian orogenic belt, and to lithosphere thickening and thinning induced by this convergence.
出处
《吉林大学学报（地球科学版）》
EI
CAS
CSCD
北大核心
2010年第4期835-844,共10页
Journal of Jilin University：Earth Science Edition
基金
国家自然科学基金项目(40772052)
南京大学内生金属成矿机制国家重点实验室基金项目(2005-2006
2006-2008
2008-2010)
