江西龙源坝地区花岗岩风化壳离子吸附型稀土矿成矿条件与分布特征

对龙源坝地区南西部山间小盆地周围的花岗岩风化壳进行踏勘调查发现,区内山形地势受燕山期NE向良伞寨断裂带和喜山期新构造的双重影响,盆地周缘多为低缓山丘,风化壳厚度大,壳层结构发育完整,是离子型稀土矿理想的赋存场所。基岩岩性主要为燕山早期粗中粒似斑状黑云母花岗岩,次为燕山晚期细粒二云母花岗岩、煌斑岩,是离子型稀土矿的成矿物质来源。研究区处于赣南粤北(稀土矿)成矿亚区,属亚热带气候,温热多雨,利于离子型稀土矿的形成。认为该区具有探寻中―小型花岗岩风化壳离子吸附型稀土矿的找矿潜力。

Metallogenic conditions and distribution characteristics of granite weathering-crustion-absorption rare earth minerals in Longyuanba area of Jiangxi

Through the reconnaissance survey on granite weathering-crust on the periphery of intermontane basin which locates at the southwest part of Longyuanba area,it is indicated that the orographic and geo-graphic features are under the influence of both Yanshaian NE-trending Xiangliangsanzhai faulted zone and Himalayan neotectonic movement.The periphery of the basin is characterized by rolling hills,and the weathering crust is thick with well-developed shell structure.It is the ideal occurrence place of ion type rare earth minerals.The lithology of basic rocks is early Yanshanian coarse-medium-grained porphyraceous bio-tite granite with minor late Yanshanian fine-grained binarygranite and lamprophyre,which are ore-forming material source of ion type rare earth minerals.This area is a part of South-Jiangxi North-Guangdong （rare earth mineral）metallogenic sub-region which is characterized by subtropical climate of intermediate tempera-ture and abundant precipitation and is favor of development of ion type rare earth minerals.It is believed that the area has favorable prospecting potential of medium-small scale granite weathering-crust ion-absorption type rare earth minerals.