云南烂泥塘斑岩型铜矿床岩体地球化学特征及矿床成因分析

摘要

烂泥塘铜矿位于义敦—中甸岛弧带南段,红山复式背斜西翼,是典型的斑岩型铜矿.铜矿床的形成与区内印支期的大规模造山运动有直接联系,矿床主要赋存于印支期石英二长斑岩岩体内.矿床围岩蚀变特征明显而强烈,与铜矿化有直接关系的是绢英岩化带.岩石地球化学特征表明:岩浆起源为中下地壳,并存在强烈地幔组分混染现象,大地构造环境为俯冲造山带的火山弧环境.铅同位素研究表明:成矿物质来源主要为下地壳,其次为上地幔,具地壳和地幔铅多来源、深源和浅源混合特征.%Lannitang copper deposit is located in the south of Yidun-Zhongdian island arc belt where is belong to the westward wing of Hongshan duplex anticline.It is a typical porphyry copper deposit and is directly related to the large-scale orogenic movement at Indo-Chinese epoch.It has been found that the deposit is mainly hosted in masanophyre which formed at the Indo-Chinese epoch.Wall rock alterations around the deposit are obvious and strong,and the phyllic alteration belt has direct relationship with copper mineralization.This paper deals with geochemical characteristics of masanophyre rock,the result shows that:The magma originated from the lower crust and strongly mixed with materiasl of mantle;The tectonic environment is the volcanic arc in the subduction zone.This paper also deals with lead sulfide isotope,the result shows that:The most materials for mineralization derived from the lower crust,some derived from the mantle.Therefore,the metallogenetic materialsare charaterized as the mixtures that come from cruse&mantle and deep & shallow sources.