【摘要】：滇西鎮(zhèn)康水頭山Pb-Zn礦床是保山地塊鎮(zhèn)康Pb-Zn-Fe-Cu多金屬礦集區(qū)內(nèi)又一重要找礦成果。礦體呈似層狀、透鏡狀產(chǎn)于上寒武統(tǒng)保山組大理巖化灰?guī)r中,呈NEE向順層產(chǎn)出,礦石礦物主要為閃鋅礦和方鉛礦,偶見黃銅礦和黃鐵礦等;脈石礦物主要有白云石、綠泥石、方解石、石英和絹云母等。本文基于對礦床地質(zhì)特征的詳細研究,結(jié)合礦床H、O、S、Pb同位素組成,對其成礦流體和礦質(zhì)來源進行了探討,同時與毗鄰的蘆子園超大型Pb-Zn-Fe-Cu多金屬礦床進行了對比。研究表明:該礦床石英的δD值介于-101.1‰~-93.3‰之間,均值為-96.85‰(n=4),δ~(18)O_(H_2O)值為3.37‰~3.77‰之間,均值為3.57‰(n=4),表明成礦流體早期以原生巖漿水為主,有大氣降水的混入。礦床金屬硫化物的δ~(34)S值均為正值,介于4.1‰~12.2‰,均值為8.23‰(n=10),與旁側(cè)的蘆子園礦床δ~(34)S值(8.9‰~12‰)較為接近。該礦床可劃分出三個成礦階段,階段Ⅱ為以閃鋅礦和方鉛礦為主的主要成礦階段(δ~(34)S主要集中在4.1‰~6.2‰之間),其δ~(34)S均值可近似代表成礦熱液中的δ~(34)S∑S值,即δ~(34)S∑S≈δ~(34)S均值=6.56‰(n=7),閃鋅礦和方鉛礦δ~(34)S值有部分重疊,但總體上具有δ~(34)S閃鋅礦δ~(34)S方鉛礦以及不同顏色閃鋅礦之間δ~(34)S深棕色閃鋅礦δ~(34)S棕褐色閃鋅礦δ~(34)S淺棕色閃鋅礦的分布特征,暗示硫同位素在硫化物間的分餾達到平衡,表明S同位素組成較為穩(wěn)定,顯示水頭山礦床具有深部殼源巖漿成因的特征。礦床金屬硫化物的Pb同位素分析顯示,Pb同位素組成非常集中(~(206)Pb/~(204)Pb=18.3408~18.4483,均值為18.3815,~(207)Pb/~(204)Pb=15.8337~15.9440,均值為15.8745,~(208)Pb/~(204)Pb=38.8224~39.4391,均值為38.9941,n=10),投點主要分布在上地殼演化線上方,表明其Pb主要來自于以巖漿作用為主的上地殼物質(zhì)。本文認為礦區(qū)深部殼源巖漿熱液是水頭山礦床最重要的成礦流體與礦質(zhì)來源,流體的混合作用是礦床金屬元素沉淀和富集的重要機制,礦床具有低溫、后生成礦特征,推測礦床的形成與燕山晚期的巖漿熱液作用有關。
[Abstract]:The Pb-Zn deposit of Zhenkang Shuitoushan in western Yunnan is another important prospecting result in Zhenkang Pb-Zn-Fe-Cu polymetallic ore concentration area of Baoshan block. The orebody is layered and lenticular in marble limestone of the Baoshan formation of the Upper Cambrian, producing in nee direction. The ore minerals are mainly sphalerite and galena, occasionally chalcopyrite and pyrite, etc. The main gangue minerals are dolomite, chlorite, etc. Calcite, quartz, sericite, etc. Based on the detailed study of the geological characteristics of the deposit and the isotopic composition of the ore deposit, the ore-forming fluid and the source of the ore-forming material are discussed and compared with the adjacent superlarge Pb-Zn-Fe-Cu polymetallic deposit in Luziyuan. The results show that the 未 D value of quartz is between -101.1 鈥，

本文編號：2136080