Origin of ring garnet in hornblendite from the Weihai area, northeast of the Sulu orogenic belt
文献类型：期刊论文
| 作者 | Liu LiShuang1,3,4; Liu FuLai1; Guo JingHui2,3,4; Cai Jia1; Zhu JianJiang1; Wang HuiNing1 |
| 刊名 | ACTA PETROLOGICA SINICA
 |
| 出版日期 | 2021-02-01 |
| 卷号 | 37期号:2页码:356-374 |
| 关键词 | Ring garnet Multistage growth Hornblendite Fluid Sulu ultrahigh-pressure belt |
| ISSN号 | 1000-0569 |
| DOI | 10.18654/1000-0569/2021.02.03 |
| 英文摘要 | Garnet featured with diagnostic texture is the best mineral to study mineral transformation and element migration in the subduction zone. Within the northeast of the Sulu ultrahigh-pressure (UHP) metamorphic belt, we first report the garnets characterized by rings within garnet -bearing hornblendite in the Weihai area by integrated studies of petrography, mineral geochemistry, zircon U-Pb geochronology and metamorphic mineral assemblages. X-ray maps show that the garnet experienced three stages of growth, according to the rings with high-Ca cores, medium-Ca inner rims and the low-Ca outer rims. These stages are named as M-1 nucleation stage, M-2 extension stage and M-3 rapid growth stage, respectively. The corresponding mineral assemblage for M-1, M-2 and M-3 are high-Ca cores in garnet ring together with mineral inclusions ( such as hornblende, plagioclase, rutile, epidote and apatite), medium-Ca rims with symplectitic plagioclase, hornblende and ilmenite, and low-Ca garnet rims, respectively, without UHP minerals or pseudomorphs. The P-T conditions of M-1 and M-2 are at 620 similar to 740 degrees C/6.8 similar to 10.4kbar and 705 similar to 775 degrees C/5.3 similar to 7.1kbar. Whereas, stage M-3 may occur at relatively lower pressure and higher temperature. From M-1 to M-2 the metamorphism is represented by the reaction of hornblende + epidote + plagioclase to garnet + hornblende + plagioclase, coupled with consumption of epidote + hornblende + plagioclase, lower Ca within garnet and higher or no obvious change of Mg content. From M-2 to M-3 the metamorphic reactants of epidote and plagioclase were nearly used up, and hornblende began to be consumed rapidly. This caused the heavy rare element (HREE), Mg and Fe contents of hornblende to enter garnet and resulted in a "bell-shaped" REE pattern of hornblende. Thus the garnet that formed during stage M-3 is characterized by very lower Ca content, higher Mg, Fe and HREE contents than those growing during M-1 to M-2 stages. In addition, U-Pb dating result of the metamorphic zircon is at 232.9 +/- 2.2Ma, indicating that the sample without UHP signature was strongly influenced by the Triassic subduction-collision process between the Yangtze Block and the North China Block. It is noted that M-3 is the key stage that the distinct ring-texture of the garnet, involving the affects of higher temperature, intergranular fluid and external infiltration fluid and resulting the rapid growth of garnet. This is because temperature and fluid can accelerate element migration and fluid can also provide enough Mg and HREE contents. In conclusion, ring garnet in the hornblendite recorded almost the whole process of growth during amphibolite-facies conditions and it is non-UHP product. |
| WOS关键词 | P-T PATH ; LIAO-JI BELT ; ULTRAHIGH-PRESSURE METAMORPHISM ; META-MAFIC ROCKS ; ZIRCON U-PB ; OXYGEN-ISOTOPE SIGNATURE ; UHP METAMORPHISM ; JIAOBEI TERRANE ; CHINA CRATON ; PELITIC GRANULITES |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000629649100003 |
| 出版者 | SCIENCE PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/101018]  |
| 专题 | 地质与地球物理研究所_岩石圈演化国家重点实验室 |
| 通讯作者 | Liu LiShuang |
| 作者单位 | 1.Chinese Acad Geol Sci, Key Lab Deep Earth Dynam Minist Nat Resources, Inst Geol, Beijing 100037, Peoples R China 2.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing 100049, Peoples R China 3.Chinese Acad Sci, Innovat Acad Earth Sci, Beijing 100029, Peoples R China 4.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China |
| 推荐引用方式 GB/T 7714 | Liu LiShuang,Liu FuLai,Guo JingHui,et al. Origin of ring garnet in hornblendite from the Weihai area, northeast of the Sulu orogenic belt[J]. ACTA PETROLOGICA SINICA,2021,37(2):356-374. |
| APA | Liu LiShuang,Liu FuLai,Guo JingHui,Cai Jia,Zhu JianJiang,&Wang HuiNing.(2021).Origin of ring garnet in hornblendite from the Weihai area, northeast of the Sulu orogenic belt.ACTA PETROLOGICA SINICA,37(2),356-374. |
| MLA | Liu LiShuang,et al."Origin of ring garnet in hornblendite from the Weihai area, northeast of the Sulu orogenic belt".ACTA PETROLOGICA SINICA 37.2(2021):356-374. |
入库方式： OAI收割
来源：地质与地球物理研究所
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