滇西分水岭矿区始新世岩浆岩成因及其构造指示：地球化学、锆石U-Pb年代学及Hf同位素制约

云南省永胜县分水岭矿区是近年发现的斑岩型铜多金属矿床。铜矿化多产于斑岩体中部外侧（喇叭箐断裂两侧）及部分岩枝的节理裂隙中,矿化与斑岩体密切相关。矿区主要侵入岩锆石LA-ICP-MS U-Pb年代学研究获得含矿石英二长斑岩的206Pb/238U加权平均年龄为36.0±0.2Ma,表明分水岭矿区斑岩体为古近纪始新世岩浆活动的产物。全岩地球化学研究显示,斑岩体Si O2含量变化较大（53.7%~71.06%）,高钾（1.67%~6.1%）和碱（Na2O＋K2O平均值〉8%）,A/CNK为0.35~1.03,属高钾的钙碱性-碱性、准铝质-过铝质斑岩;富集大离子亲石元素（Rb、K、La、Nd、Hf）、亏...

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Bibliographic Details
Published in地质与勘探 Vol. 53; no. 6; pp. 1070 - 1089
Main Author 周洁;王根厚;崔银亮
Format Journal Article
LanguageChinese
Published 中国地质大学(北京)地球科学与资源学院,北京 100083 2017
中国海洋大学海洋地球科学学院,山东青岛 266100%中国地质大学(北京)地球科学与资源学院,北京,100083%云南有色地质局,云南昆明,650051
Subjects
Lu-Hf
分水岭
始新世
斑岩
滇西
锆石U-Pb
锆石U-Pb
斑岩
Fenshuiling
滇西
Lu-Hf
zircon U-Pb
western Yunnan Province
Eocene
始新世
分水岭
porphyry
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ISSN0495-5331
DOI10.3969/j.issn.0495-5331.2017.06.004

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Summary:云南省永胜县分水岭矿区是近年发现的斑岩型铜多金属矿床。铜矿化多产于斑岩体中部外侧（喇叭箐断裂两侧）及部分岩枝的节理裂隙中,矿化与斑岩体密切相关。矿区主要侵入岩锆石LA-ICP-MS U-Pb年代学研究获得含矿石英二长斑岩的206Pb/238U加权平均年龄为36.0±0.2Ma,表明分水岭矿区斑岩体为古近纪始新世岩浆活动的产物。全岩地球化学研究显示,斑岩体Si O2含量变化较大（53.7%~71.06%）,高钾（1.67%~6.1%）和碱（Na2O＋K2O平均值〉8%）,A/CNK为0.35~1.03,属高钾的钙碱性-碱性、准铝质-过铝质斑岩;富集大离子亲石元素（Rb、K、La、Nd、Hf）、亏损高场强元素（Ta、Nb、P、Ti）,富集轻稀土元素,亏损重稀土元素,具A2型花岗岩特征。斑岩体锆石Hf同位素研究,得到εHf（t）值为-8.70~＋4.67,地壳模式年龄（tDMC）为533.7Ma~1062.8Ma,显示矿区始新世斑岩体来源于壳幔岩浆的混合。结合区域演化特征,认为分水岭斑岩体形成于造山期后的拉张环境,陆陆碰撞挤压后应力松驰,岩浆沿断裂及次级断裂上侵,进而形成铜多金属矿床。
Bibliography:ZHOU Jie1.2 ,WANG Gen-hou1 ,CUI Yin-liang3 （ 1. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083 ; 2. College of Marine Geosciences, Ocean University of China, Qingdao, Shandong 266100 ; 3. Nonferrous Geological Bureau of Yunnan Province, Kunming, Yunnan 650051 ）
The Fenshuiling mine is a large porphyry type copper-polymetallic deposit in Yongsheng County of Yunnan Province. The copper mineralization of this district is closely related to the porphyry,and orebodies mainly occur in the porphyry and outer hornfels zone. This work studied the bulk geochemistry,zircon U-Pb dating and Hf isotopes of the porphyry from this mining area. The zircon U-Pb age of porphyry samples is 36. 0 ± 0. 2 Ma,indicating that the porphyry of this mine area is the product of the Eocene magmatic activity. Geochemical characters of the porphyry show large variation in SiO 2（ 53. 7% ~ 71. 06%）,high in K2 O（ 1. 67% ~ 6. 1%） and Na2 O ＋ K2 O（〉 8%）,and the ratio of A/CNK is 0. 35 ~ 1. 03,and the porph
ISSN:0495-5331
DOI:10.3969/j.issn.0495-5331.2017.06.004