Transcrustal magma plumbing process in the Cenozoic Dali potassic lamprophyre dyke formation in the southeastern Tibet Plateau | |
Zhang, Shitao1,4; Long, Xiaoping3,4; Zhang, Fangyi5; Zhang, Le2 | |
刊名 | LITHOS |
2023-10-01 | |
卷号 | 454页码:15 |
关键词 | Lamprophyre Clinopyroxene Oscillatory zoning Transcrustal magmatic processes |
ISSN号 | 0024-4937 |
DOI | 10.1016/j.lithos.2023.107281 |
通讯作者 | Long, Xiaoping(longxp@nwu.edu.cn) |
英文摘要 | (Ultra-)potassic lamprophyres are volumetrically rare, but are widely distributed in diverse geological settings and extensively applied to trace the mantle source and melting processes. However, it is still debatable whether the lamprophyre formation involved transcrustal magmatic processes. In this study, we describe the diverse zoning patterns and textures of clinopyroxene (Cpx) from a Cenozoic potassic lamprophyre dyke in southeastern Tibet Plateau. Three types of Cpx macrocrysts with normal- and reverse oscillatory zoning and sieved textures, and Cpx microcrysts from Cpx-Phl nodules are recognized. The Cpx macrocrysts have highly variable Mg# (62-89) and chemical compositions. Their oscillatory-zoned mantle has alternating coarse layers or closelypacked layers, with distinct resorption surface shown in backscattered electron (BSE) images. High-amplitude oscillation of Mg# (& PLUSMN;5 to & PLUSMN;12), Al, Cr and Sr at the boundary layers of mantle may reflect multiple magma mixing/recharge events. In contrast, low-amplitude and high-frequency oscillation of Mg# (varying from < & PLUSMN;3) across the closely-packed layers could be attributed to local magma mixing or kinetic effect at the crystal-melt interface. The sieved domains occur in the Cpx macrocrystic core with spongy space and linking the external groundmass by cracks, and have major and minor compositions and 87Sr/86Sr ratios similar to those of the rims. This indicates that the sieved domains are probably originated from dissolution of the Cpx macrocrysts by groundmass melt and later reprecipitation. The estimated pressure and temperature for the Cpx macrocryst highMg# cores and low Mg# rims are 580-1160 MPa (avg. 919 MPa) and 30-1270 MPa (avg. 681 MPa), and 1116-1266 |
资助项目 | National Key Research and Development Project[2019YFA0708601] |
WOS关键词 | LITHOSPHERIC THINNING BENEATH ; ULTRAPOTASSIC ROCKS ; GEOCHEMICAL CONSTRAINTS ; ALKALINE LAMPROPHYRES ; WESTERN YUNNAN ; MANTLE SOURCE ; CLINOPYROXENE ; PLAGIOCLASE ; PETROGENESIS ; EVOLUTION |
WOS研究方向 | Geochemistry & Geophysics ; Mineralogy |
语种 | 英语 |
出版者 | ELSEVIER |
WOS记录号 | WOS:001041546900001 |
内容类型 | 期刊论文 |
源URL | [http://ir.qdio.ac.cn/handle/337002/182708] |
专题 | 海洋研究所_深海极端环境与生命过程研究中心 |
通讯作者 | Long, Xiaoping |
作者单位 | 1.Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Peoples R China 2.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 3.Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Northern Taibai Str 229, Xian 710069, Peoples R China 4.Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Peoples R China 5.Chinese Acad Sci, Inst Oceanol, Ctr Deep Sea Res, Qingdao 266071, Peoples R China |
推荐引用方式 GB/T 7714 | Zhang, Shitao,Long, Xiaoping,Zhang, Fangyi,et al. Transcrustal magma plumbing process in the Cenozoic Dali potassic lamprophyre dyke formation in the southeastern Tibet Plateau[J]. LITHOS,2023,454:15. |
APA | Zhang, Shitao,Long, Xiaoping,Zhang, Fangyi,&Zhang, Le.(2023).Transcrustal magma plumbing process in the Cenozoic Dali potassic lamprophyre dyke formation in the southeastern Tibet Plateau.LITHOS,454,15. |
MLA | Zhang, Shitao,et al."Transcrustal magma plumbing process in the Cenozoic Dali potassic lamprophyre dyke formation in the southeastern Tibet Plateau".LITHOS 454(2023):15. |
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