摘要
南秧田矽卡岩型白钨矿床是滇东南老君山钨锡多金属成矿区的重要组成部分之一。该矿床由多个白钨矿体组成,以层状、似层状矽卡岩型矿石为主,矽卡岩矿物组合以透辉石+钙铁辉石+钙铝榴石+角闪石+绿帘石为主。南秧田钨矿床的形成经历了矽卡岩阶段,石英-白钨矿阶段和方解石阶段,通过对不同阶段矿石矿物和脉石矿物的流体包裹体显微测温分析表明:矽卡岩中的流体包裹体的均一温度范围为221~423℃,石英-白钨矿的均一温度为177~260℃,晚期方解石脉的温度最低,为173~227℃。矽卡岩中的流体包裹体的盐度w(Na Cleq)为0.18%~16.34%,石英-白钨矿的盐度w(Na Cleq)为0.35%~7.17%,晚期方解石脉的盐度w(Na Cleq)为0.35%~2.24%。激光拉曼探针测试表明,3个阶段的流体包裹体组分主要为H2O,还有少量的N2,只有在石英-白钨矿阶段的流体包裹体组分除了H2O以外,还有少量的CH4。矿床从早期到晚期成矿阶段表现为一个降温的过程,说明钨成矿温度较宽泛。成矿期含矿矽卡岩的δ13CPDB值为-5.7‰^-6.9‰,δ18OSMOW值为5.8‰~9.1‰,表明成矿流体主要是岩浆水,其次为含有机质的碳酸盐岩地层和大气降水,反映出典型岩浆热液交代作用的特征。
The Nanyangtian skarn-type scheelite deposit is an important part of the Laojunshan W, Sn polymetallic metallogenic area in Yunnan Province. The deposit is made up of multiple scheelite orebodies, and the multi-layer skarn-type scheelite orebodies are dominated. The skarn minerals mainly consist of diopside, hedenbergite, hessonite, epidote etc. The formation of the tungsten deposit experienced a period composed of skarn phase, quartz-scheelite phase and calcite phase. According to the microthermometry of fluid inclusions in gangue and ore minerals from different phases, the authors hold that the homogenization temperatures of fluid inclusions in skarn have a range of 221-423℃, the homogenization temperature range of fluid inclusions in the quartz-scheelite stages is 177-260℃,and late calcite veins have the lowest range of 173-227℃; the salinity w（NaCleq） of fluid inclusions in skarn has a range of 0.18%-16.34%, the salinity w（NaCleq） range of fluid inclusions in the quartz-scheelite stages is 0.35%-7.17%, and late calcite veins have the range of 0.35%-2.24%. Raman microspectroscopic studies of the fluid inclusions of three phases show that the main component is H2O,with a little N2.At the quartz-scheelite stage, besides H2O, a little gas of CH4 is existent in the fluid inclusions. From the early to the late mineralization stages,the cooling processes might occur, which reflects the broad mineralization temperature of tungsten. The δ13CPDB values of ore-bearing skarn in the mineralization period range from -5.7‰ to -6.9‰, with the corresponding δ18OSMOW values between 5.8‰ and 9.1‰. This implies that the ore-forming fluid was formed by magma metasomatism, whose composition was mainly magmatic water together with a little meteoric water.
作者
蔡倩茹
燕永锋
杨光树
贾福聚
崔东豪
李超
CAI QianRu;YAN YongFeng;YANG GuangShu;JIA FuJu;CUI DongHao;LI Chao(Kunming University of Science and Technology, Kunming 650093 Yunnan, Chin)
出处
《矿床地质》
CAS
CSCD
北大核心
2018年第1期116-136,共21页
Mineral Deposits
基金
国家自然科学基金项目"滇东南矿集区层控矽卡岩成因与成矿作用"(编号:41373050)项目资助
作者简介
蔡倩茹，女，1992年生，在读博士，主要从事矿床地球化学，岩石地球化学研究。Email：502912480@qq．com;通讯作者燕永锋，男，1970年生，教授，从事矿床地球化学，数学地质等研究。Email：yyf701018@vip．sina．com
