藏东衣珠兴拉地区水系沉积物地球化学特征与找矿远景划分

西藏衣珠兴拉地区位于班公湖-怒江带东段,属于阿尔卑斯-喜马拉雅巨型系构造带向南转折的藏东三江地区,构造-岩浆活动强烈,具有良好的多金属矿成矿条件,是寻找铬铁、铅锌多金属矿的有利地区。依据1/5万水系沉积物测量成果研究表明:1)通过分析元素地球化学特征、元素相关性分析,认为Ag、Au、Cu、Pb、Zn、Sb等为本地区主要成矿元素;2)利用因子分析研究了元素组合特征及异常分布规律,结合成矿地质条件和已知矿床(点)信息,认为该区多金属矿化与燕山期岩浆热液成矿作用有关,具有明显的高中低温分带性;(3)划分出4处多金属矿成矿远景区,即拉桑卡-尼尼拉卡铬铁矿Ⅰ级成矿远景区、母拉同Ⅰ级成矿远景区、根达卡-曲功马Ⅱ级成矿远景区、摘龙-瓦昌达铅锌钨锡多金属成矿远景区Ⅱ级成矿远景区。

Geochemical characteristics of drainage sediments in the Yizhuxingla area of Eastern Tibet,China and the prospecting prospect analysis

The Yizhuxingla area of Tibet,located in the eastern section of the Bangong Lake-Nujiang River belt,is in the Eastern Tibetan Sanjiang area,which is a transition part turing from eastward to southward in the tectonic belt of the Alpine-Himalaya giant system.The strong tectonic-magmatic activity occurred in the area which has good polymetallic metallogenic conditions,and is a favorable area for exploring Ferrochrome,Pb-Zn polymetallic resources.The 1/50,000 scale geochemical survey and research of drainage sediments in the area have been carried out in this paper.(1)Based on the analyses of the geochemical characteristics and elemental correlation of elements,it is considered that Ag,Au,Cu,Pb,Zn,and Sb are main metallogenic elements in this area;(2)Based on the characteristics of element associations and abnormal distribution regularities,obtained by using the factor analysis of geochemical data,combined with metallogenic geological conditions and information of known deposits(mineral occurrences),it is considered that the polymetallic mineralization in this area could be related to the metallogenesis of the Yanshanian magmatic hydrothermal fluids,with obvious zonation from high,medium,to low temperatures.(3)4 prospective targets for prospecting polymetallic resources have been outlined.They are the Lasanka-NiniLaca first class chromite prospecting target,the Mulatong first class Pb-Zn-Ag polymetallic prospecting target,the Gendaka-Qugongma second class Pb-Zn-Mo-Cu polymetallic prospecting target,and the Zhailong-Wachangda second class Pb-Zn-W-Sn polymetallic prospecting target.