摘要
东桃铅锌矿床矿石中发育典型的纹层状构造和软沉积滑动变形构造 ,成矿流体偏酸性及相对富钠贫钾 ,富钙贫镁特点 ,表明铅来源以地层沉积物为主。硫主要来源于沉积岩或海水硫酸盐。成矿环境为一种相对还原环境 ,矿体直接围岩是一种喷流岩。
Dongtao Lead-Zinc deposit is distributed in Silurian metamorphic rock of south -eastern Guangxi. There are many layers of ore bodies which have bedded appea rance,and have the same occurrence with the wall rocks. The direct country rock is bedded skarn which includes diopside-quartz-epidote rock,chlorite-epidote rock,chlorite-quartz rock and quartz-marble etc. Typical laminated structure and soft sedimentary-slipping deformed structure are common in the ores. Determ ini ng of fluid inclusion shows even-temperature is 98-256℃,salinity is 0.35-6.5% NaCl,and the fluid is acid,relatvely rich in K + and poor in Na +,rich in Ca 2+and poor in Mg 2+,which is similiar with the modern ocean-floor hy drothermal solution.Pb isotope shows the feature of J-Pb, and come close to the uooer earth's crust curve in evolving diagram of Pb isotope.Deduce Pb origina ted mainly from sediment of strata.S isotope δ 34S value concentrates in 0~3‰ and came mainly from sedimentary rocks or sulfates in sea water. Rare-ear th elements in ore and skarn show the loss of Eu and have no Ce abnormaly, which indicates the ore-forming surroundings were relatively reduced.Dongtao depos ite formed in the background of regional syngenetic tension fault's activity,s ubmarine volcano eruption and regional exhalative-sedimentary mineralization. It's ancient location of lithofacies was in the transitional district between continental shore's edge slope and deep sea basin.Submarine hydrothermal activ ity had the feature of intermittent pulsation and formed many Layers of altern ating bedded ore bodies and widespread Laminated structure. Mineralization in turbulent sea-floor slope formed soft sedimentary-slipping deformed stucture. Bedded skarn is a kind of exhalative rock.
出处
《矿产与地质》
2000年第5期333-336,共4页
Mineral Resources and Geology
关键词
地球化学
铅锌矿床
矿床地质
成矿作用
流体包裹体
成因
Guangxi Dongtao Lead-Zinc deposit
Bedded Skarn
Fluid inclusion
Pb and S isotope
Rare earth element
Exhalative sedimentation
