湘南两类铅锌矿床的铅同位素组成特征

一、前言湘南的两类铅锌矿床,主要指的是东坡、香花岭矿田的铅锌、锡铅锌矿床和产于泥盆纪的层控铅锌矿床。前一类矿床的形成,不仅与燕山期花岗岩类小岩体密切有关,而且具有明显的地层效应,集中产于中上泥盆统棋梓桥组、佘田桥组碳酸盐岩中。如香花岭矿田的铅锌矿床约有80％的矿床(点)都集中产于棋梓桥组上段下部的白云岩和白云岩化灰岩内,同时还受到断裂构造的控制。以往的多数研究者认为,东坡、香花岭矿田的铅锌矿床,其成因属于典型的岩浆期后热液

Lead Isotopic Composition Of Two Types Of Lead-Zinc Deposits In Southern Hunan

The two types of lead-zinc deposits occurring in Devonian strata of southern Hunan refer to deposits in famous Dongpo and Xianghualing ore fields and deposits far from small Yensbanian granitic bodies. Based on 27 analyses of lead isotopic composition (Table l, Fig. 1) , combined with geological and geochemical setting of the deposits, the present paper deals preliminarily with such problems as sources of ore-forming materials, metallogenic phases and stages, ore genesis and evolution of the earths crust in Hunan in the light of lead isotopic composition, source of lead in ore (Fig. 2), lead isotopic chronometry (Fig.3) and sources and two-stage evolution of metallic ore materials(Figs. 4 and 5), indicating that the two types of lead-zinc deposits might be products of the same metallogenic series closely related to each other in genesis.