Geology and Metallogenetic Setting of the Habo PorphyryCu (Mo-Au) Deposit, Yunnan

哈播斑岩铜(-钼-金)矿床位于哀牢山-红河新生代成矿带南端西侧,是近年来新发现的一个斑岩型矿床.矿区内出露的哈播侵入体具有多期侵入的特征,花岗岩依次侵入的序列为坪山花岗岩、三道班花岗岩、阿树花岗岩、哈播南山花岗岩(37.3 Ma),随后有4期斑岩侵入到哈播南山花岗岩中,依次为黑云母钾长石斑岩、石英钾长石斑岩、石英二长斑岩和晚期黑云母钾长石斑岩岩脉.采用LA-ICP-MS锆石U-Pb年龄法测定黑云母钾长石斑岩和石英二长斑岩的加权平均年龄分别为36.20±0.20 Ma和36.19±0.22 Ma,哈播南山花岗岩和4期斑岩具有相似的岩石地球化学特征,都有富钾、高氧化态和类似岛弧花岗岩的岩石地球化学特征,可能具有相同的来源.辉钼矿Re-Os年龄显示,哈播矿床的成矿年龄为35.47±0.16 Ma.相似的成岩-成矿年龄暗示哈播矿床成岩和成矿作用是一个连续的岩浆-热液过程,与玉龙斑岩铜矿相似.基于哈播矿床的岩石学、地球化学特点,结合前人关于青藏高原东部斑岩铜矿的研究成果,我们认为哈播斑岩矿床可能为藏东富碱斑岩带向东南的延伸,与玉龙斑岩铜矿带具有相似的成因,为哀牢山-红河新生代成矿带的重要组成部分,是晚碰撞构造转换背景下的重要产物.Habo porphyry Cu (-Mo-Au) deposit, located in west of southern Ailaoshan-Red River Cenozoic metallogentic belt, is a newly-discovered deposit. The Habo intrusion complex cropping out in this district is characterized with multiple intrusions. Granite based on this intrusion sequence can be divided into Pingshan granite, Sandaoban granite, Ashu granite and Habo South granite intrusion (c. 37.3 Ma), then followed by four porphyries intruding into the Habo South granite, i.e. biotie-K-feldspar porphyry, quartz-K-feldspar porphyry, quartz-monzonitic porphyry and later biotie-K-feldspar porphyry dykes. LA-ICP-MS U-Pb dating of zircons from biotie-K-feldspar porphyry and quartz-monzonitic porphyry yields ages of c. 36.20±0.20 Ma and c. 36.19±0.22 Ma, respectively. The Habo South granite intrusion and four stages of porphyry are of the similar geochemical features (high K and alkaline, high oxidization and arc granite) as the porphyry belt in Eastern Tibet, indicating that both have a same origin. Re-Os dating of molybdenum mineralization shows an age of c. 35.47±0.16Ma for the Habo deposit. The extremely similar intrusive age may suggest that diagenesis and mineralization in the Habo deposit was a continuous magmatic hydrothermal process, similar to the Yulong porphyry copper deposit. Basing on the lithological and geochemical characteristics of the Habo deposit, the authors in combination with previous research results in this area believe that the alkaline porphyry deposit in eastern Tibet is the extension of Yulong metallogenic belt and the product in a late-collisional transform regime in Eastern Tibet.国家重点基础研究发展规划(973计划); 国家自然科学基金重点项目; 高等学校创新引智计划; 成矿动力学基地项目; 国家自然科学基金; 国家地质大调查项目中文核心期刊要目总览(PKU)中国科技核心期刊(ISTIC)中国科学引文数据库(CSCD)0121915-19288