中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
New insights into Cryogenian arc granitoids hosting Th-U mineralized Ediacaran syenogranite dikes, Ra's Abdah area in the northern Egyptian Nubian Shield: Constraints from U-Pb ages and zircon geochemistry

文献类型:期刊论文

作者Dessouky, Osama K.5; Sun, Weidong1,3,4; Ibrahim, Waleed S.5; Ali, Hani H.5; Hassan, Mahmoud M.2; Li, Congying1; Omran, Ali A.5; Dardier, Ahmed M.5
刊名PRECAMBRIAN RESEARCH
出版日期2021
卷号352页码:18
ISSN号0301-9268
关键词Egyptian nubian-shield Ra's Abdah, dikes Cryogenian-ediacaran Zircon geochemistry Th-U mineralization
DOI10.1016/j.precamres.2020.105986
英文摘要

During the transition from compressional to extensional-related magmatism, at Ra's Abdah area of the northern Eastern Desert of Egypt, Ediacaran uraniferous syenogranite dikes with complex morphology sent offshoots into Cryogenian arc granitoids. This study defines new tectonic environment of these dikes and suggests their emplacement timing before the Egyptian late-collision granite intrusions. U-Pb zircon dating for Ra's Abdah dikes and arc granitoids yielded ages 597 +/- 15 and 663.2 +/- 8.4 Ma respectively; that extended the age of late Precambrian post-orogenic dikes in the Egyptian Nubian Shield to 597 +/- 15 Ma. Zircons from dikes show significant enrichment of Th and U; while zircons from arc granitoids display typical igneous zircon patterns with Th and U enrichment but significant negative Nb, La, Pb and Sr anomalies. Average calculated zircon temperature crystallization of Ra's Abdah dikes is 698 degrees C whereas of the granitoids is 713 degrees C. Similar geochemical behavior of some individual trace elements and REE in zircons from dikes and host rocks intimates identical magma source (partial melting of subducted oceanic crust and its overlying magmatic wedge intercalated with older continental crust). High fractional crystallization of the parent magma after the first pulse managed the change from arc granitoids magma with high fO(2) values to syenogranite dikes phase with lower fO(2) following the transformation from a transpressional to an extensional tectonic. Volatile complexing in late-magmatic stage, mineral fractionation and concomitant zircon crystallization would increase all REE in the residual melt with special HREE enrichment and LREE elimination in zircon of dikes. The radioactive mineralization of dikes (Averaging eU = 124.7 ppm; eTh = 263.9 ppm) are syn-genetic followed by supergene enrichment. Suggested model explains the multistage propagation of complex morphology dikes by filling, opening and increasing expansibility of inclined or perpendicular pre-existing fracture framework.

WOS研究方向Geology
语种英语
出版者ELSEVIER
WOS记录号WOS:000600065200016
版本出版稿
源URL[http://ir.qdio.ac.cn/handle/337002/169507]  
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Dessouky, Osama K.
作者单位1.Chinese Acad Sci, Ctr Deep Sea Res, Inst Oceanol, Qingdao 266071, Peoples R China
2.Suez Canal Univ, Geol Dept, Ismailia, Egypt
3.Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China
4.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao 266237, Peoples R China
5.Nucl Mat Author Egypt, POB 530, Cairo, Egypt
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GB/T 7714
Dessouky, Osama K.,Sun, Weidong,Ibrahim, Waleed S.,et al. New insights into Cryogenian arc granitoids hosting Th-U mineralized Ediacaran syenogranite dikes, Ra's Abdah area in the northern Egyptian Nubian Shield: Constraints from U-Pb ages and zircon geochemistry[J]. PRECAMBRIAN RESEARCH,2021,352:18.
APA Dessouky, Osama K..,Sun, Weidong.,Ibrahim, Waleed S..,Ali, Hani H..,Hassan, Mahmoud M..,...&Dardier, Ahmed M..(2021).New insights into Cryogenian arc granitoids hosting Th-U mineralized Ediacaran syenogranite dikes, Ra's Abdah area in the northern Egyptian Nubian Shield: Constraints from U-Pb ages and zircon geochemistry.PRECAMBRIAN RESEARCH,352,18.
MLA Dessouky, Osama K.,et al."New insights into Cryogenian arc granitoids hosting Th-U mineralized Ediacaran syenogranite dikes, Ra's Abdah area in the northern Egyptian Nubian Shield: Constraints from U-Pb ages and zircon geochemistry".PRECAMBRIAN RESEARCH 352(2021):18.

入库方式: OAI收割

来源:海洋研究所

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