广东大宝山铜矿英安斑岩的同位素组成与蚀变特(9)
BACKGROUND:The main types of copper deposits are porphyry and skarn porphyry is a rock type commonly developed in the porphyry Cu-Mo-Au rock can be used as a marker clue for ore prospecting and ore-forming rock when there is well-developed hydrothermal Dabaoshan deposit is currently the largest copper polymetallic deposit in the South China studies have shown that the dacite porphyry of the mining area is not only the ore-forming parent rock,but also a favorable ore-bearing wall ,there are some debates about the relationship between dacite porphyry and mineralization in this mining the breakthrough of prospecting for medium and large dacite porphyry ore bodies in recent years,the relationship between dacite porphyry and mineralization has once again become a concern.
OBJECTIVES:To understand the relationship between dacite porphyry alteration and mineralization of the Dabaoshan deposit.
METHODS:Based on field work and indoor analysis,X-ray fluorescence spectroscopy (XRF) and inductively coupled plasma-mass spectrometry (ICP-MS) were used to determine copper,tungsten,silicon,aluminum and calcium in Dabaoshan dacite porphyry isotope composition,metal element contents and alteration characteristics of the dacite porphyry in the mining area were used to discuss the relationship between alteration and prospecting direction.
RESULTS:The copper content ranged from 107 to 6909μg/g,which was consistent with the copper ore grade of 0.3%-0.5% in the mining area.The LOI and other geochemical indicators that can represent the degree of alteration were positively correlated with alteration was widely developed in dacite porphyry,including potassium,prophyliticition and quartz-sericitization from early to late different stages of alterations,the copper content of quartz-sericitization was 2 to 5 times higher than other alteration types,indicating that quartz-sericitization was closely related to copper mineralization and was an important prospecting marker clue.
CONCLUSIONS:The deep alteration intensity of the dacite porphyry (below the 270m elevation) has not been weakened,suggesting a great prospecting addition,the contact zone between dacite porphyry and the Jurassic strata,and the xenoliths in the dacite porphyry are also important prospecting directions,which may host skarn-type copper-rich deposits.
文章来源:《华南国防医学杂志》 网址: http://www.hngfyxzz.cn/qikandaodu/2021/0118/406.html