摘要
对浙东南地区两类铅锌(银)矿床氧、铅、硫、碳的稳定同位素系统研究表明,尽管这两类矿床的成因类型不同,但由于它们均产于中生代火山岩系内,其成矿围岩之性质相近,因而,它们的成矿物质来源大同小异,主要表现在脉状矿床和层状矿床后期改造之成矿热液皆以大气降水为主;在脉状矿床成矿早期的热液中,尚含有一定量的岩浆水,大气降水的循环以深部为主,晚期则基本为大气降水,其循环以浅部为主。脉状矿床之铅源较层状矿床要复杂,但它们均属壳幔混合型。这两类矿床中的硫及碳皆以深部源为主,但脉状矿床之硫源相对较复杂。层状矿床的碳部分来自盆地的化学沉积物。
Systematic studies of the stable isotopes O, Pb, S and C in the vein and stratiform Pb-Zn (Ag) deposits in southeastern Zhejiang Province show that hydrothermal solutions producing vein ore deposits and those causing reworking of stratiform ore deposits are composed mainly of meteoric waters. However, at the early mineralization stage was still involved a certain amount of magmatic water, although deep circulating groundwater is dominant. At the late stage were almost entirely involved meteoric waters circulating at shallow depth. The element Pb in these two types of deposits can all be assigned to the mantle-crust mixing type. It was stemmed from the subduction of the Pacific Plate that led to mixing of the Pb from both upper mantle and lower crust with that in terrigeneous material and chemical sediments overlying the plate. Circulating meteoric waters and uprising hydrothermal solutions would dissolved part of the element in the upper crust, and then it mingled with that originally contained in the hydro-thermal solutions. The main source of S and C in these two types of ore deposits is the same as that in the country rocks, probably related to volcanism. But C in the stratiform deposits was derived partly from chemical sediments of terrigeneous origin.
出处
《地球化学》
CAS
CSCD
北大核心
1992年第2期125-132,共8页
Geochimica
