滇西北白秧坪多金属矿集区东矿带方解石REE地球化学特征及意义  

Significance and Characteristics of REE Geochemistry in Calcite in the Eastern Ore Belt of the Baiyangping Poly-Metallic Metallogenic Province,Northwestern Yunnan Province,China

作　　者：冯彩霞[1] 毕献武[1] 武丽艳[1] 邹志超[1,2] 唐永永[1,2] 

机构地区：[1]矿床地球化学国家重点实验室/中国科学院地球化学研究所,贵阳550002 [2]中国科学院研究生院,北京100049

出　　处：《吉林大学学报（地球科学版）》2011年第5期1397-1406,共10页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(40972071);国家重点基础研究发展计划项目(2009CB421005)

摘　　要：方解石是白秧坪多金属矿集区东矿带矿石中的主要脉石矿物。不同产状矿体中方解石的REE地球化学特征研究表明,3个矿段成矿期方解石具有2种稀土模式:LREE(轻稀土元素)富集型和相对平坦型;前者表明成矿过程中没有LREE明显带出的迹象,残余热液继承了前期成矿热液的特征,而后者表明成矿过程中有LREE带出。不同类型矿体方解石中REE含量、有关参数和稀土配分模式等均变化较大,但在地球化学特征上具有连续变化规律,显示为同源不同阶段的产物。方解石为热液成因方解石,结合其他同位素的资料和矿区的地质背景,得出成矿流体以大气降水与围岩反应形成的热卤水为主、深部流体参与其成矿作用的观点。成矿过程中,由早到晚,成矿环境表现为还原向氧化环境变化。Calcite is a dominant gangue mineral in the eastern ore belt of Baiyangping poly-metallic metallogenic province.Geochemical characteristics of rare earth element（REE） of calcite from different ore bodies reveal that there are two types of REE distribution patterns： light rare earth element（LREE）-enriched and flat REE.The former represents that the REE behavior of calcite is that of inherited from pre-hydrothermal ore-forming hydrothermal features and the LREE was not apparently carried out during the mineralization process.The latter indicates that LREE was apparently brought out during the mineralization process;the REE content,relevant parameters and REE distribution patterns of calcite from different types of ore bodies change significantly,but they show continuous change tendency;combined with other isotope data and geological background of the mine,it is considered that ore-forming fluids were mainly hot brines and some mantle fluid participated in the ore forming process;The ore-forming conditions change from the reducing to oxidizing ones during the metallogenic process.

关 键 词：REE 地球化学 方解石 白秧坪东矿带 滇西北 

分 类 号：P595[天文地球—地球化学]