华南早寒武世黑色岩系重晶石矿床环带钡冰长石新发现及其意义  

First Discovery of Zoned Hyalophane in the Barite Deposits Hosted in Early Cambrian Black Shales of South China and Its Geological Implications

作　　者：韩善楚[1,2] 胡凯[1] 曹剑[1] 

机构地区：[1]内生金属矿床成矿机制研究国家重点实验室,南京大学地球科学与工程学院,南京210093 [2]核资源与环境教育部重点实验室,东华理工大学地球科学学院,南昌330013

出　　处：《地质论评》2013年第6期1143-1149,共7页Geological Review

基　　金：国家自然科学重点基金资助项目(编号41373044);内生金属矿床成矿机制研究国家重点实验室研究项目(编号2008-II-07);核资源与环境教育部重点实验室开放基金资助项目(编号090902)的成果

摘　　要：华南早寒武世黑色岩系重晶石矿床是全球著名的沉积型层状矿床。本文报道了我们最近的一项新发现,在该区天柱大河边重晶石矿床中首次发现了环带钡冰长石,环带的外带BaO含量16.53%～17.86%,K2O含量7.77%～8.19%,相比而言,核部BaO含量12.04%～14.21%,K2O含量8.60%～9.79%。结合成矿地质背景和已有工作报道,讨论了这一新发现的地质意义。认为这种环带钡冰长石的出现,反映了重晶石成矿受到热水作用影响,且其形成过程中经历了不同期富钡流体的影响,成矿可能属于一种热水、断控、幕式、渐进的过程,这不仅进一步揭示了矿床的热水(液)喷流沉积成因,而且加深了对成矿过程的刻画。该认识还可供全球沉积型重晶石矿床成因研究时类比参考。The barite deposits hosted in Early Cambrian black shales in South China is one of the representative world famous sediment-hosted stratiform deposits. This paper reports the discovery of zoned hyalophane for the first time, based on a case study in the Dahebian barite deposits, Tianzhu county, South China. Analytical results of electron microprobe analysis show that outer BaO content is 16.53% to 17.86% and K20 content is 7.77% to 8.19%, while BaO content is 12.04% to 14.21% and K20 content is from 8.60% to 9.79% in the core. Combined with the geological setting and previous research results, we addressed geological implications of this discovery. It supports the impact of hydrothermal liquid in the formation of the barite deposit. Multiple stages of barium-rich fluid participated in the barite formation, and the mineralization was fault controlled, episodic and progressive. This not only further implies the hydrothermal sedimentary genesis of the deposit, but also betters the understanding of mineralization process. These results may have general implications to the other studies worldwide, as the Dahebian deposit is the biggest in volume of such deposits in the world.

关 键 词：天柱大河边 重晶石矿床 钡冰长石 环带 热水 早寒武世 华南 

分 类 号：P578.968[天文地球—矿物学]