摘要
新桥矿床是长江中下游成矿带铜陵矿集区内典型的大型层控矽卡岩型铜金硫多金属矿床。矿床成矿过程中除了铜、金、铁、硫等主要成矿元素富集成矿以外,钴、硒、碲等关键金属元素也以伴生形式产生了不同程度的富集。前人对新桥矿床开展了大量研究工作,但对矿床中关键金属钴、硒、碲的分布规律、赋存状态和富集机制等方面系统研究尚未开展。本次研究在新桥矿床系统采集距离成矿岩体不同位置的两条代表性剖面(3804、E601)的岩矿石样品,通过光学显微镜观察、扫描电子显微镜、全岩主微量元素化学分析和矿物原位LA-ICP-MS微量成分测试等分析技术方法,查明了矿床中钴、硒、碲等关键金属的空间分布规律和赋存状态,初步探讨了钴、硒、碲的富集机制。新桥矿床中估算伴生Co、Se、Te资源量分别为:2326t、2590t、1463t,达到大-中型规模。近成矿(热)中心3804剖面Co、Se含量自矿体底板→顶板呈逐渐降低的趋势,Te含量变化没有明显规律,Co、Se、Te均主要在黄铁矿矿石中产生富集;远成矿(热)中心E601剖面上Co、Se、Te含量自矿体底板→顶板均呈逐渐降低的趋势,且主要富集高品位黄铁矿矿石中。矿体走向上自成矿(热)中心→远端,Co含量明显降低,Se、Te含量相对增高。矿床中Co、Se主要以类质同象置换的形式赋存于黄铁矿中,Te的赋存状态以独立碲矿物为主,包括辉碲铋矿和碲银矿。Co主要在石英-硫化物阶段产生富集,成矿流体温度较高,流体中Co大部分随黄铁矿沉淀富集于近成矿(热)中心的黄铁矿矿石中,至碳酸盐-硫化物阶段,成矿流体温度降低,流体中Se、Te大部分沉淀富集于远成矿(热)中心的高品位黄铁矿矿石中,其中Se主要随黄铁矿大量沉淀富集,Te较少进入黄铁矿等硫化物中,主要以独立矿物的形式产出。
Xinqiao deposit is a typical large stratiform skarn-type copper-gold-polymetallic deposit located in Tongling ore cluster within the Middle-Lower Reaches of the Yangtze River Metallogenic Belt.In addition to the enrichment of copper,gold,iron and sulfur,critical elements such as cobalt,selenium and tellurium are also enriched during the mineralization process.Previous studies have conducted many researches on the Xinqiao deposit,but systematic investigations on the distribution patterns,occurrence states and enrichment mechanisms of cobalt,selenium and tellurium in the deposit have not been carried out.In this study,representative rock and ore samples were collected from two profiles(3804 and E601)located at different distances from the ore-forming rock body.Analytical techniques such as optical microscopy,scanning electron microscopy,whole-rock major and trace element analysis and in-situ LA-ICP-MS trace element testing of minerals were employed to find out the spatial distribution patterns and occurrence states of cobalt,selenium and tellurium in the deposit.Subsequently,the enrichment mechanisms of cobalt,selenium and tellurium was preliminarily explored.The estimated resources of associated cobalt,selenium and tellurium in the Xinqiao deposit are approximately 2,326 tons,2,590 tons and 1,463 tons,respectively,reaching a large to medium-sized scale.In the near-mineralization(thermal)center(3804 profile),the content of cobalt and selenium decrease gradually from the bottom to the top of the orebody,and there is no obvious pattern of change in tellurium content.Cobalt,selenium and tellurium are predominantly enriched in pyrite ores.In the far-mineralization(thermal)center(E601 profile),the content of cobalt,selenium and tellurium also decrease gradually from the bottom to the top of the orebody and are mainly enriched in high grade pyrite ores.Along the strike of orebody from the mineralization(thermal)center to the distal end,the cobalt content decreases significantly,while the selenium and tellurium content re
作者
石磊
周涛发
肖鑫
SHI Lei;ZHOU TaoFa;XIAO Xin(Ore Deposit and Exploration Centre(ODEC),School of Resources and Engineering,Hefei University of Technology,Hefei 230009,China;Anhui Province Engineering Research Center for Mineral Resources and Mine Environments,Hefei 230009,China;School of Earth and Environment,Anhui University of Science and Technology,Huainan 232001,China)
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2023年第10期3031-3047,共17页
Acta Petrologica Sinica
基金
国家自然科学基金项目(91962218)
国家重点研发计划项目(2022YFC2903503)联合资助.
关键词
新桥矿床
关键金属
空间分布规律
赋存状态
富集机制
Xinqiao deposit
Critical metals
Spatial distribution pattern
Occurrence state
Enrichment mechanism
