摘要
东宫下高岭土矿为我国特大型的优质高岭土矿床之一。通过对该矿床的成矿地质条件的分析,表明蚀变花岗岩岩体上部的低铁白云母钠长石花岗岩与强风化带叠加是形成优质高岭土矿的基础;发育的断裂、节理和裂隙构造为良好的控矿条件;由适宜的温湿气候所造成的弱酸性水介质条件使得风化成矿作用终止于氧化作用的开始阶段;低温热水则加速了原生矿物的分解和高岭石族矿物的形成;平缓的低山丘陵和厚度不大的盖层为高岭土矿体的保存创造了良好的条件。通过对花岗岩风化壳剖面的研究,说明该矿床形成是在亚热带表生地质作用条件下,低铁含稀有金属蚀变花岗岩的铝硅酸盐矿物(长石)分解转化为粘土矿物(高岭石族、水云母等)而形成风化壳的过程。
Donggongxia Kaolin Deposit in Longyan,Fujian Province is one of the extraordinary-scale good-quality kaolin deposits in China.The paper focuses on the discussion of the ore-formation conditions and its mechanism.Based on the study of the geological conditions of forming the deposit,it is indicated that
the basic condition of forming the kaolin deposit is the superposition of low-ferriferrous muscovite-albite
granite in the upper part of altered granite body on the strongly weathered zone,that the development
of faults,fissures and joints in the area is one of the important ore-controlled conditions,that the weak-
acid medium caused by the warm and moist climate improves the weathering ore-formation,that the
low-temperature hydrothermal activity improved decomposition of primary minerals and the formation
of kaolinite minerals and that the gentle hills and thinner cover are a good condition of preserving the
orebodies.According to the analysis of the granitic weathered crust,it is concluded that the formation
of the deposit is the process that the weathered crust is formed when the salic minerals(feldspar)of low-
ferriferrous REE-bearing altered granite are decomposed and turn into clay minerals(kaolinite group and
hydromuscovite).
出处
《福建地质》
1991年第4期247-269,共23页
Geology of Fujian
