Geochemistry of porphyries and volcanic rocks and ore-forming geochronology of Duobuza gold-rich porphyry copper deposit in Bangonghu belt, Tibet: Constraints on metallogenic tectonic settings
文献类型：期刊论文
| 作者 | Li JinXiang; Li GuangMing; Qin KeZhang; Xiao Bo |
| 刊名 | ACTA PETROLOGICA SINICA
 |
| 出版日期 | 2008-03-01 |
| 卷号 | 24期号:3页码:531-543 |
| 关键词 | Duobuza gold-rich porphyry copper deposit zircon SHRIMP U-Pb dating geochemistry high Nb basalt (HNB) adakite tectonic setting Bangonghu belt Tibet |
| ISSN号 | 1000-0569 |
| 文献子类 | Article |
| 英文摘要 | Duobuza copper deposit, located in the north of Bangonghu-Nujiang suture, possesses giant perspective, representative gold-rich porphyry copper deposit in Tibet. On the base of geochemistry of ore-forming porphyry, basaltic volcanic rock, distinguish three series of rock: adakites, high Nb basaltic rocks (HNB) and normal arc volcanic rocks. All rocks belong to cale-alkaline series, with SiO2 ranging from 47% to 68%, Al2O3 13% to 18%, MgO 1.4% to 8.5%, FeOt 2.3% to 8.1% and CaO 2.1% to 10%. MgO, MnO and FeOt abundance exhibit a negative correlation with SiO2, K2O exhibit a positive correlation with SiO2. The high Nb basaltic rocks and normal are volcanic rocks are enrichment in Na, Na2O/K2O ranging from 0.9 to 7, whereas adakites have more enrich in K2O. Total concentration of REE, with ranging from 29 x 10(-6) to 203 x 10(-6), gradually decreases from ultramafic to felsic rocks, and high Nh basaltic rock ( HNB) have the highest IREE concentration, whereas adakites have the lowest. Chondrite-normalized REE patterns are LREE-rich, with LREE/HREE 7.0 similar to 12.4, (La/Yb)(N) not asymptotic to 3. 2 similar to 13, delta Eu 0. 9 similar to 2. 1. The adakites and normal arc basaltic andesites are systematically more enriched in large-ion lithophile elements (LILE: Rb, Ba, Sr, K), more mobile highly incompatible lithophile elements ( HILE: U, Th) and relatively depleted in high field strength elements (HFSE: Nb, Ta, Zr, Hf, Ti), and these geochernical characteristics suggest they have the characteristics of subduction-related magma. However, high Nb basaltic rocks are characterized by Nb, Ta positive anomaly, high TiO2 (> 2%) and low (La/Nb)(PM) ratios (< 2). Trace element geochemistry and Sr-Nd isotope characteristics suggest that adakitic magma directly derived by partial melting of subduction ocean crust, with the addition of subduction sediments. High Nb basaltic rocks (HNB) are products of a mantle souce, enriched in Nh, Ta, metasomatized by a adakitic melt or supercritical fluid, likely with the infiltration of asthneosphere material. Normal are basaltic andesites derived from mantle wedge metasomatized by hydrous fluids from subduction dehydration. In addition, the spatial association of the HNB with adakites "adakitic metasomatic volcanic series", indicate Duobuza porphyry copper deposit form in the typical island arc subduction setting. Ore-forming granodiorite porphyry zircon have obvious oscillatory zone, Th/U (0.51 similar to 0.90) ratio > 0. 1, indicate zircon is magmatic genesis, and its SHRIMPU-Pb gave an age of 121.6 +/- 1.9Ma, suggests Banonghu-Nujiang ocean were subducting northward at least during approximate 120Ma, and the closure time of this ocean should later than early Cretaceous. |
| WOS关键词 | HIGH-FIELD-STRENGTH ; SUBDUCTION-ZONE FLUIDS ; NB-ENRICHED BASALTS ; ISLAND-ARC BASALTS ; ELEMENT ENRICHMENT ; CHEMICAL CLASSIFICATION ; SOUTHERN PHILIPPINES ; MINDANAO PHILIPPINES ; CONTINENTAL-CRUST ; SUPERIOR PROVINCE |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000259117700013 |
| 出版者 | SCIENCE CHINA PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/69382]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Li JinXiang |
| 作者单位 | Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100029, Peoples R China |
| 推荐引用方式 GB/T 7714 | Li JinXiang,Li GuangMing,Qin KeZhang,et al. Geochemistry of porphyries and volcanic rocks and ore-forming geochronology of Duobuza gold-rich porphyry copper deposit in Bangonghu belt, Tibet: Constraints on metallogenic tectonic settings[J]. ACTA PETROLOGICA SINICA,2008,24(3):531-543. |
| APA | Li JinXiang,Li GuangMing,Qin KeZhang,&Xiao Bo.(2008).Geochemistry of porphyries and volcanic rocks and ore-forming geochronology of Duobuza gold-rich porphyry copper deposit in Bangonghu belt, Tibet: Constraints on metallogenic tectonic settings.ACTA PETROLOGICA SINICA,24(3),531-543. |
| MLA | Li JinXiang,et al."Geochemistry of porphyries and volcanic rocks and ore-forming geochronology of Duobuza gold-rich porphyry copper deposit in Bangonghu belt, Tibet: Constraints on metallogenic tectonic settings".ACTA PETROLOGICA SINICA 24.3(2008):531-543. |
入库方式： OAI收割
来源：地质与地球物理研究所
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