矿床地质2024，Vol.43Issue(1)：177-194,18.DOI:10.16111/j.0258-7106.2024.01.011
粤东金坑锡铜多金属矿燕山期岩浆热液叠加成矿
Yanshanian magmatic hydrothermal superimposed mineralization in Jinkeng Sn-Cu polymetallic deposit,eastern Guangdong Province
摘要
Abstract
The Jinkeng Sn-Cu polymetallic deposit is located in northeastern part of the Lianhuashan fault in Guang-dong Province.It has long been hotly debated about its genesis.Hydrothermal cryptoexplosive breccia is first dis-covered in Mashan ore section of Jinkeng Sn-Cu polymetallic deposit by core logging and petrographic observa-tion,and the hydrothermal activity can be divided into 5 stages in detail.On this basis,this paper carried out de-tailed zircon U-Pb dating of granitic breccia in hydrothermal cryptoexplosive breccia,and detailed in-situ sulfur isotope analysis of sulfide.The granite have zircon U-Pb age about 150 Ma,have εHf(t)values ranging from-8.20 to-4.55,and Hf model ages(TDM2)of 1.72～1.49 Ga,suggesting that the granite formed by the partial melting of Mesproterozoic crustal material,and contain a minor mantle-derived component.In-situ sulfur isotope analysis of sulfides show that there are obvious differencesed in sulfur isotopic composition of sulfides from different stages.Significantly,the sulfur isotope changes in pyrite of different stages before crushing(Py-Ⅰ:-0.65‰ to 1.11‰,n=5)and after deformation(Py-Ⅱ:1.30‰to 1.93‰,n=5),and the δ34S of chalcopyrite associated with Py-Ⅱis 1.42‰to 1.87‰(n=16).Chalcopyrite in the third stage have high δ34S values ranging from 3.69‰to 4.32‰(n=4),in which the δ34S value of chalcopyrite in cryptoexplosive breccia cement(Ccp-Ⅲa:3.69‰to 3.74‰),which is slightly lower than that in quartz-chlorite vein(Ccp-Ⅲb:4.29‰to 4.32‰).The pyrite from the fourth stage have lower δ34S value(Py-Ⅳ:-4.87‰,n=1;Ccp-Ⅳ:-3.07‰,n=1).Considering that the tin deposits in Jinkeng and its adjacent area are mainly formed in～144 Ma,while the copper deposit is formed in 170～150 Ma.It is considered that there are at least two magmatic and hydrothermal events in Jinkeng deposit,in which the granitic magmatic activity derived from crust-mantle mixing of～150 Ma may be an important magmatic event to trigger Cu mineraliza-tion in the mining area.This work could hopefully promote the Sn and Cu prospecting along Lianhuashan fault belt.关键词
莲花山断裂/热液叠加/锡铜多金属矿/粤东Key words
Lianhuashan fault/hydrothermal superposition/tin-copper polymetallic deposit/eastern Guang-dong分类
天文与地球科学引用本文复制引用
孙海瑞,吕志成,李永胜,韩志锐,于晓飞,杜轶伦..粤东金坑锡铜多金属矿燕山期岩浆热液叠加成矿[J].矿床地质,2024,43(1):177-194,18.基金项目
本文得到国家重点研发计划课题(编号:2022YFC2905101)、科技基础资源调查专项课题(编号:2022FY101701)、中国地质调查局项目(编号:DD2023350、DD20221692)联合资助 （编号:2022YFC2905101）
