CAJ | 학술논문

西藏冈底斯成矿带拉抗俄斑岩铜钼矿床位于西藏特提斯构造域拉萨地块东段中南部，是近年来青藏高原地质大调查项目评价的重点矿床之一。本文在钻孔地质编录的基础上，采用辉钼矿Re-Os同位素测年技术，对拉抗俄铜钼矿床中8件产于花岗闪长斑岩中的辉钼矿进行定年，获得了拉抗俄矿床辉钼矿成矿年龄，辉钼矿Re-Os模式年龄为(13.20±0.20) Ma~(13.64±0.21) Ma，加权平均值为（13.38±0.15）Ma，等时线年龄为（13.12±0.44）Ma，代表了拉抗俄斑岩铜钼矿床的成矿时代，成矿作用发生于中新世。辉钼矿中Re的含量为343.6×10-6~835.7×10-6，平均557.8×10-6，指示其成矿物质中有幔源物质加入。拉抗俄斑岩铜钼矿床形成于印度—亚洲大陆碰撞造山带碰撞过程的伸展背景，其成矿年龄与冈底斯斑岩铜矿带东段中亚带众多斑岩-矽卡岩成矿系统年龄基本一致（17~12 Ma），相对于同一矿集区的驱龙、甲玛、邦铺斑岩-矽卡岩型铜多金属矿的成矿年龄小2~3 Ma，但其形成受控于相同的成矿地球动力学背景。
서장강저사성광대랍항아반암동목광상위우서장특제사구조역랍살지괴동단중남부，시근년래청장고원지질대조사항목평개적중점광상지일。본문재찬공지질편록적기출상，채용휘목광Re-Os동위소측년기술，대랍항아동목광상중8건산우화강섬장반암중적휘목광진행정년，획득료랍항아광상휘목광성광년령，휘목광Re-Os모식년령위(13.20±0.20) Ma~(13.64±0.21) Ma，가권평균치위（13.38±0.15）Ma，등시선년령위（13.12±0.44）Ma，대표료랍항아반암동목광상적성광시대，성광작용발생우중신세。휘목광중Re적함량위343.6×10-6~835.7×10-6，평균557.8×10-6，지시기성광물질중유만원물질가입。랍항아반암동목광상형성우인도—아주대륙팽당조산대팽당과정적신전배경，기성광년령여강저사반암동광대동단중아대음다반암-석잡암성광계통년령기본일치（17~12 Ma），상대우동일광집구적구룡、갑마、방포반암-석잡암형동다금속광적성광년령소2~3 Ma，단기형성수공우상동적성광지구동역학배경。
The Lakange porphyry Cu-Mo deposit in the Gangdise metallogenic belt of central and southern East Lhasa block within the Tethys tectonic domain is one of the key deposits in the Tibet Plateau geological survey project evaluation in recent years. Re-Os isotopic dating technique was applied for determination of mineralization events, and eight molybdenite samples were analyzed for Re-Os isotopic compositions, with the model ages obtained ranging from (13.20±0.20) Ma to (13.64±0.21) Ma, and the isochron age being(13.12 ± 0.44)Ma which represents the metallogenic age of the Lakange porphyry Cu-Mo deposit, indicating Miocene. The Re content of the molybdenite is 343.6 × 10-6-835.7 × 10-6, with an average of 557.8 × 10-6, suggesting that the metallogenic material originated from a source with mantle components. The Lakange porphyry Cu-Mo deposit was formed in a stretching background of India-Asia continental collision orogenic collision, the age (17-12 Ma) is identical with ages of numerous porphyry-skarn mineralization systems in the eastern of Gangdise metallogenic belt, and is 2-3 Ma younger than ages of the porphyry-skarn copper polymetallic deposits in the same ore concentration area, such as Jiama, Qulong and Bangpu, with the formation controlled by the same metallogenic geodynamics setting.