Knowledge Management System Of Guangzhou Institute of Geochemistry，CAS
| Zhao, Zisong1,2,3; Wang, Christina Yan1,2,4; Dou, Jingzhao1,2; Wei, Bo1,2,4 | |
| A Mush-Facilitated Magma Mixing Process Revealed by Complex Zoning of Plagioclase in Mafic Magmatic Enclaves of the Early Cretaceous Sanguliu Granitic Pluton, East China | |
| Source Publication | JOURNAL OF PETROLOGY
 |
| ISSN | 0022-3530 |
| 2023-07-01 | |
| Volume | 64Issue:7Pages:21 |
| DOI | 10.1093/petrology/egad048 |
| Language | 英语 |
| WOS Research Area | Geochemistry & Geophysics |
| Abstract | Mafic magmatic enclaves (MMEs) hosted in granitic plutons are ideal to investigate the role of mushes on magma mixing processes in crustal magma chambers. However, the petrographic evidence for mixing of magmas through infiltration and percolation in coexisting mushes and magmas is desired. Here, we describe complex zoning patterns of plagioclase in the MMEs hosted in the monzogranite of the Early Cretaceous Sanguliu pluton in East China to reveal a mush-facilitated magma mixing process. The MMEs appear as round to oval nodules about 10 to 20 cm in size and show diverse disequilibrium textures. Plagioclase in the MMEs can be identified as three populations (Plag1, Plag2, and Plag3) with distinct zoning patterns, anorthite contents (X-An) and initial Sr isotopic ratios (Sr-87/Sr-86(i)). Plag1 is antecryst displaying normal zoning with An(42-67) in the core and An(20-36) in the mantle. The core of Plag1 shows coarse sieve texture with high-frequency oscillation in the margin, and the mantle displays resorption surface and patchy zoning. Plag2 is also antecryst with An(23-66) in the core and An(21-35) in the mantle. However, its core can be further recognized as Core I inside and Core II outside with distinctly different An(23-43) and An(44-66), respectively, showing reverse zoning. In addition, Core I contains aligned biotite inclusions and Core II shows sieve texture, resorption surface and patchy zoning. Amphibole inclusions are sporadically enclosed within Core I of Plag2 (Amp1) and mantles of Plag1 and Plag2 (Amp2), but rarely observed in Core II of Plag2. Plag3 is anhedral grain in the matrix and shows core-rim texture with An(20-37) in the core. The three plagioclase populations all exhibit angular rims with resembling An(9-22). Plag1 core and Plag2 Core II have (Sr-87/Sr-86)(i) (0.70920 to 0.71092) similar to the bulk (Sr-87/Sr-86)(i) of the mafic dykes intruding the Sanguliu pluton, and likely crystallized from basaltic andesitic magmas. In contrast, the rims of Plag1, Plag2, and Plag3 overall have (Sr-87/Sr-86)(i) (0.71391 to 0.71583) nearly identical to the (Sr-87/Sr-86)(i) of host monzogranite and the plagioclase in the monzogranite, likely crystallized from granitic magmas. The mantles of Plag1 and Plag2 and the core of Plag3 have (Sr-87/Sr-86)(i) (0.71141 to 0.71390) overlapping the (Sr-87/Sr-86)(i) of the MMEs, and may have crystallized from mixed melts. Calculation results based on amphibole thermobarometers show that Amp1 crystallized at similar to 775 degrees C and similar to 16 km depth, whereas Amp2 and the amphibole in the matrix of the MMEs and monzogranite crystallized at 730 to 744 degrees C and 8 to 9 km depth. We thus propose that the chemical and textural complexity of the three plagioclase populations in the MMEs can be attributed to that the MMEs may have come from a mushy hybrid layer that was developed through a molten granitic body being recharged by upwelling basaltic andesitic magma. Core I of Plag2 may have nucleated and grown from andesitic magma that was evolved from the basaltic andesitic magma from which the core of Plag1 and Core II of Plag2 crystallized. |
| Keyword | mush-facilitated mixing plagioclase zoning mafic magmatic enclaves (MMEs) Sanguliu granitic pluton East China |
| WOS ID | WOS:001036025600003 |
| Indexed By | SCI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.gig.ac.cn/handle/344008/74563 |
| Collection | 中国科学院矿物学与成矿学重点实验室 |
| Corresponding Author | Wang, Christina Yan |
| Affiliation | 1.Chinese Acad Sci, Guangzhou Inst Geochem, CAS Key Lab Mineral & Metallogeny, Kehua St, Guangzhou 510640, Peoples R China 2.CAS Ctr Excellence Deep Earth Sci, Guangzhou, Peoples R China 3.Univ Chinese Acad Sci, Beijing, Peoples R China 4.Guangdong Prov Key Lab Mineral Phys & Mat, Guangzhou 510640, Peoples R China |
| Recommended Citation GB/T 7714 | Zhao, Zisong,Wang, Christina Yan,Dou, Jingzhao,et al. A Mush-Facilitated Magma Mixing Process Revealed by Complex Zoning of Plagioclase in Mafic Magmatic Enclaves of the Early Cretaceous Sanguliu Granitic Pluton, East China[J]. JOURNAL OF PETROLOGY,2023,64(7):21. |
| APA | Zhao, Zisong,Wang, Christina Yan,Dou, Jingzhao,&Wei, Bo.(2023).A Mush-Facilitated Magma Mixing Process Revealed by Complex Zoning of Plagioclase in Mafic Magmatic Enclaves of the Early Cretaceous Sanguliu Granitic Pluton, East China.JOURNAL OF PETROLOGY,64(7),21. |
| MLA | Zhao, Zisong,et al."A Mush-Facilitated Magma Mixing Process Revealed by Complex Zoning of Plagioclase in Mafic Magmatic Enclaves of the Early Cretaceous Sanguliu Granitic Pluton, East China".JOURNAL OF PETROLOGY 64.7(2023):21. |
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