【摘要】：多彩地瑪鉛鋅礦位于青藏高原東北緣的青海玉樹地區(qū),夾持于西金烏蘭-金沙江縫合帶與班公湖-怒江縫合帶之間,屬于"三江"北段銅鉛鋅銀多金屬成礦帶。結(jié)合區(qū)域地質(zhì)調(diào)查及研究現(xiàn)狀,對礦區(qū)圍巖碳酸鹽巖和兩期熱液方解石脈開展了C-O同位素組成分析,對硫化物礦石礦物和重晶石進(jìn)行了S同位素組成分析。結(jié)果表明:賦礦圍巖中方解石的δ~(13)C和δ~(18)O值范圍分別為-1.6‰~+3.0‰和+21.2‰~+27.6‰,屬于正常海相碳酸鹽巖沉積,C和O來自海水;方解石脈體的δ~(13)C和δ~(18)O的值范圍分別為-1.5‰~+2.1‰和+15.2‰~+20.3‰,C來自海相碳酸鹽巖的溶解作用,~(18)O因熱液蝕變碳酸鹽巖在水/巖反應(yīng)中同位素交換作用的影響而明顯虧損;硫酸鹽重晶石的δ~(34)S值范圍為+12.3‰~+15.7‰,硫化物方鉛礦、閃鋅礦和黃鐵礦的δ~(34)S值范圍為-8.2‰~+5.7‰,峰值為-2.0‰~-3.0‰,反映了總體富輕硫的特征,硫源主要為盆地?zé)猁u水萃取地層蒸發(fā)巖中硫酸鹽,并通過有機(jī)質(zhì)熱分解反應(yīng)還原為低價硫分餾而得到;硫化物較寬的δ~(34)S變化范圍反映了成礦物質(zhì)在盆地內(nèi)流體活動期間與不同地層單元發(fā)生相互作用,盆地內(nèi)富有機(jī)質(zhì)地層中沉積或生物成因S也有可能為成礦提供了部分硫源。
[Abstract]:The Daima Pb-Zn deposit is located in the Yushu area of Qinghai Province on the northeast margin of the Qinghai-Tibet Plateau. It is located between the Xijin Wu Lan Jinsha River suture zone and the Bangong Lake Nujiang suture zone, and belongs to the copper, lead, zinc and silver polymetallic metallogenic belt in the northern section of the Sanjiang River. Combined with the present situation of regional geological investigation and research, C-O isotopic compositions of carbonate rocks and two-stage hydrothermal calcite veins were analyzed, and S isotopic compositions of sulphide ore minerals and barite were analyzed. The results show that the 未 ~ (13) C and 未 ~ (18) O values of calcite in the host rock are -1.6 鈥，

本文編號：2130999