摘要
邦铺钼铜多金属矿床位于西藏冈底斯斑岩铜矿带东段,是典型的大型斑岩型钼铜多金属矿床,二长花岗斑岩为其成矿母岩。对邦铺二长花岗斑岩的岩石学和地球化学的研究表明,此二长花岗斑岩富硅(67.06%～73.70%)、富K2O(3.61%～7.642%)贫CaO(0.14%～4.40%)贫Na2O(0.140%～4.40%),属钾玄岩系列及高钾钙碱性系列。稀土总量变化变化很大(22.01×10-6～107.606×10-6),稀土曲线为平缓的右倾型,轻稀土元素相对富集,重稀土元素相对亏损。δEu的变化范围为0.592～1.064,具有微弱的负铕异常到无铕异常。岩石微量元素相对富集不相容元素(LILE),贫高场强元素(HFSE),即相对富集Rb,U,Cs和Nd而亏损Ba,Sr,P,Ti和Y。二长花岗斑岩形成的环境比较复杂,主要为同碰撞造山构造环境,即印度大陆与亚洲大陆碰撞造山带内,发育与碰撞后的地壳伸展环境,并可能涉及到冈底斯区域板块俯冲碰撞作用的多个阶段。
The Bangpu Mo-Cu polymetallic deposit is one of the typical large-scale porphyry deposit,located in the eastern Gangdese metallogenic belt,Tibet,with its mother rock as monzonite granite-porphyry.Detailed petrographic and geochemical studies show that the monzonite granite porphyry in Bangpu belongs to high-K calc-alkaline series,rich in SiO2（67.06%～73.70%）,K2O（3.61%~7.642%）,poor in CaO（0.14% ~4.40%）and Na2O（0.140%~4.40%）.The monzonite granite porphyry is characterized by high content of ΣREE and vary greatly from 22.01×10-6 to 107.606×10-6,rich in LREE,low in HREE,with a weak negative to normal Eu anomaly ranging from 0.592～1.064.Trace elements are characterized by LILE enrichment in Rb,U,Cs and HFSE depletion in Ba,Sr,P,Ti and Y.The formation environment of monzonite granite porphyry is complex,resulted from mainly in syn-collisional tectonic setting of Indian-Asian continental collision,from the post collision extension and involved in multiple stages of subduction of the Gangdese plate.
出处
《矿物岩石》
CAS
CSCD
北大核心
2010年第4期48-54,共7页
Mineralogy and Petrology
基金
"十一五"国家科技支撑计划项目(2006BAB01A04)
关键词
二长花岗斑岩
地球化学
特征
构造意义
西藏邦铺
monzonite granite porphyry
geochemical characteristics
tectonic significance
syn-collision
Bangpu of Tibet
