Geochemistry and petrogenesis of Laojungou Mengtonggou granites in western Sichuan, China: constraints on the nature of Songpan-Ganzi basement
文献类型：期刊论文
| 作者 | Zhao YongJiu; Yuan Chao; Zhou MeiFu; Yan DanPing; Long XiaoPing; Li Jiliang |
| 刊名 | ACTA PETROLOGICA SINICA
 |
| 出版日期 | 2007-05-01 |
| 卷号 | 23期号:5页码:995-1006 |
| 关键词 | Songpan-Ganzi terrane granites source composition Nd model ages part-melting of the lower crust underplating nature of the basement |
| ISSN号 | 1000-0569 |
| 文献子类 | Article |
| 英文摘要 | The Mesozoic Laojungou and Mengtonggou granitic plutons in the eastern part of the Songpan-Ganzi terrane represent products of a major orogenic granitic magmatism and contain important information about the nature of the basement. These granites are intermediate- to high-K cale-alkaline, with intermediate to high SiO2 (63.9 similar to 75.0 wt% )and metaluminous to mildly peraluminous characteristics (ACNK = 0.86 similar to 1.08). Rocks of the Laojungou pluton contain high Al2O3 (14.2 similar to 16.0 wt%) and K2O(2.88 similar to 4.36 wt%) but low MgO (0.38 similar to 1.98 wt%). The Laojungou pluton has relatively high Sr (307 similar to 697 ppm) and low Y (12.2 similar to 21.0 ppm) with fractionated REE ((La/Yb)(N) > 10) and relatively high Sr/Y ratios (22 similar to 55), and resembles adakitic crustal melts. The Mengtonggou pluton is quite similar to the Laojungou pluton in most major and trace element characteristics, except for its relatively low Sr (110 similar to 397 ppm) high Y (12.2 similar to 21.0 ppm) and strikingly low Sr/Y ratios (5 similar to 32). The two plutons all exhibit crustal Nd-Sr isotope compositions ( epsilon(Nd) (T) = -6.02 similar to -3.11; I-Sr = 0.7053 similar to 0.7075), indicating that these granites were not mantle-derived, but most likely resulted from partial melting of lower crustal materials in the garnet stability field. The high Rb (106 similar to 202 ppm), Cs (3.79 similar to 25.6 ppm) contents and intermediate to high K2O/Na2O ratios (0.56 - 1.12) of both plutons are consistent with their generation from dehydration of biotite. The relatively high temperature for biotite dehydration precludes shear-heating as the cause for the genesis of these plutons, and requires an underplating or intraplating scheme of mantle-derived magma to fuse the crustal materials. The two plutons possess similar, Mid-proterozoic T-DM ages (T-DM(II) = 1.23 similar to 1.44 Ga), which together with their geochemical compositions, indicate that the Songpan-Ganzi terrane is underlain with the Yangzi-type basement. |
| WOS关键词 | GARZE OROGENIC BELT ; I-TYPE PLUTONISM ; U-PB ; TIBETAN PLATEAU ; FOLD BELT ; EASTERN MARGIN ; HIGH-POTASSIUM ; CALC-ALKALINE ; SOUTH CHINA ; EMPLACEMENT |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000248135100013 |
| 出版者 | SCIENCE CHINA PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/68516]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Zhao YongJiu |
| 作者单位 | 1.Chinese Acad Sci, Guangzhou Inst Geochem, Guangzhou 510640, Peoples R China 2.Henan Univ, Coll Environm & Planning, Kaifeng 475001, Peoples R China 3.Univ Hong Kong, Dept Earth Sci, Hong Kong, Hong Kong, Peoples R China 4.China Univ Geosci, Sch Earth Sci & Min Resources, Beijing 100083, Peoples R China 5.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zhao YongJiu,Yuan Chao,Zhou MeiFu,et al. Geochemistry and petrogenesis of Laojungou Mengtonggou granites in western Sichuan, China: constraints on the nature of Songpan-Ganzi basement[J]. ACTA PETROLOGICA SINICA,2007,23(5):995-1006. |
| APA | Zhao YongJiu,Yuan Chao,Zhou MeiFu,Yan DanPing,Long XiaoPing,&Li Jiliang.(2007).Geochemistry and petrogenesis of Laojungou Mengtonggou granites in western Sichuan, China: constraints on the nature of Songpan-Ganzi basement.ACTA PETROLOGICA SINICA,23(5),995-1006. |
| MLA | Zhao YongJiu,et al."Geochemistry and petrogenesis of Laojungou Mengtonggou granites in western Sichuan, China: constraints on the nature of Songpan-Ganzi basement".ACTA PETROLOGICA SINICA 23.5(2007):995-1006. |
入库方式： OAI收割
来源：地质与地球物理研究所
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