摘要
长安大型金矿床位于哀牢山成矿带南段,矿区内出露煌斑岩、辉长岩、辉绿岩、正长花岗岩、正长花岗斑岩等岩株和岩脉,矿体均与脉岩共生或相互切穿。各类岩浆岩和矿石的地质、岩相学、岩石地球化学的系统研究表明,矿区内岩浆岩可能为同源岩浆演化产物,但煌斑岩、辉绿岩与矿化关系更为密切。金成矿物质具有壳幔混源的特点,成矿流体由岩浆水与地层变质水混合而成。在喜山期,强烈的壳幔相互作用过程导致了区内的岩浆和热液活动,大规模富碱岩浆上侵的热驱使岩浆水循环并与矿区地层在造山作用下脱水产生的富CO2的变质水混合,萃取地层及略早形成的脉岩中的Au等成矿元素,在适宜的物理化学条件下和成矿空间内卸载并富集成矿。
The Chang'an large gold deposit is located in the southern Aillaoshan metallogenic belt. There are lamprophyre,gabbro,dolerite,syenogranite and syenogranite porphyry stocks or dykes. The ore bodies and dykes occur together or cut each other. The studies on geological and geochemical characteristics of the magmatic rocks and ores show that they might be sourced from the same origin and there should be closer relationship between lamprophyre,dolerite and mineralization. The metallogenic materials were mainly from mantle as well as strata,and the ore-forming fluid was sourced from magmatic water and metamorphic water. During the collisional orogenesis process in Himalayan period,the violent complex crust-mantle interaction coursed the magma and fluid activities in Ailaoshan region. The ascent of large scale alkali-rich magma drove the magma fluid circulate and mixed with the metamorphic CO2-rich water. The mixed fluid extracted gold and other metallogenetic elements from the wall rock or dyke,migrated and finally precipitated them in the proper structural spaces under some physical-chemical condition.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2010年第6期1740-1750,共11页
Acta Petrologica Sinica
基金
国家重点基础研究发展规划项目(2009CB421006)
"111"计划(B07011)
中国地质大学地质过程与矿产资源国家重点实验室(MSFGPMR201018)资助
关键词
岩浆岩
岩石地球化学
长安金矿床
哀牢山成矿带
三江特提斯
Magmatite
Rock geochemistry
Chang'an gold deposit
Ailaoshan metallogenic belt
Sanjiang Tethys
