黄沙坪铅锌银多金属矿床硫铅同位素地球化学特征  

Sulfur and Lead Isotope Geochemical Characteristics of the Huangshaping Lead, Zinc and Silver Polymetallic Deposit

作　　者：刘悟辉[1] 汪礼明[1] 徐文忻[2] 李蘅[2] 戴塔根[1] 

机构地区：[1]中南大学,湖南长沙410083 [2]桂林矿产地质研究院,广西桂林541004

出　　处：《地球学报》2005年第B09期160-163,共4页Acta Geoscientica Sinica

基　　金：本文为原有色金属工业总公司地质局资助项目.

摘　　要：对黄沙坪矿床硫化物期矿物进行矿物包裹体温度和成分测定，并进行热力学计算，获得毒砂-闪锌矿阶段成矿温度为300℃，logfco2为0．4～1．4；logfCH4为-2．05～2．07；logfH2O1.67～1．93；logfo2为-32.87～-38．39。对矽卡岩期和硫化物期硫化物进行硫同位素测定，获得矽卡岩期黄铁矿的δ^34S为4．1‰～4．6‰；硫化物期硫化物的δ^34S为6．2‰～17．5‰，并具有δ^34SSp大于δ^34SGn和两组δ^34S∑S值。对长石、方铅矿和闪锌矿进行了铅同位素测定，获得长石的^206Pb／^204Pb比值为18．429-19．305，^207Pb／^204Pb比值为15．598-15．905;^208Pb／^204Pb比值为38．647～39．235。方铅矿和闪锌矿的^206Pb／^204Pb比值为18．00～18．772，^207Pb／^204Pb比值为15．580-16．045，^208Pb／^204Pb比值为38．490～41．560，并呈线性排列，显示矿床硫铅是两种以上的物质来源。The determination and thermodynamic calculation of the temperature and composition of the sulfide-stage mineral inclusions from the Huangshaping ore deposit indicate that the ore-forming temperature of the arsenopyrite-sphalerite ore-forming stage is 300℃, logfCO2 are 0.4- 1.4, logfCH4 are - 2.05-2.07, logfH2O are 1.67- 1.93, and logfO2 are - 32.87- - 38.39. The deterruination of sulfur isotopes of the skarn and sulfide stage sulfides shows that δ^34S values of pyrite at the skarn stage are 4.1%- 4.6%, δ^34S values of sulfides at the sulfide stage are 6.2%-17.5%, and that δ^34SSp〉δ^34SGn. The determination of δ^34S∑S reveals that δ^34S∑S is 5‰, and δ34S∑S is 19‰. The detemaination of lead isotopes of feldspar, galena and sphalerite indicates that ^206Pb/ ^204Pb ratios of feldspar are 18. 429- 19. 305, ^207Pb/^204Pb ratios are 15. 598- 15. 905, and ^208Pb/^204Pb ratios are 38. 647-39. 235. ^206Pb/^204Pb ratios of galena and sphalerite are 18.00-18. 772, ^207Pb/^204Pb ratios are 15. 580-16. 045, and ^208Pb/^204Pb ratios are 38. 490-41. 560, assuming linear arrangement. All these data suggest that sulfur and lead in the ore deposit were derived from more than two kinds of material sources.

关 键 词：铅锌银矿床 成矿条件 硫铅同位素 黄沙坪 铅锌银多金属矿床 同位素地球化学特征 硫化物 ^208PB 矿物包裹体 同位素测定 

分 类 号：P618.2[天文地球—矿床学] P597[天文地球—地质学]