干旱区生态环境知识资源中心(Arid): 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

Arid

DOI	10.1016/j.precamres.2020.105986
	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
	Dessouky, Osama K.; Sun, Weidong; Ibrahim, Waleed S.; Ali, Hani H.; Hassan, Mahmoud M.; Li, Congying; Omran, Ali A.; Dardier, Ahmed M.
通讯作者	Dessouky, OK (corresponding author), Nucl Mat Author Egypt, POB 530, Cairo, Egypt.
来源期刊	PRECAMBRIAN RESEARCH
ISSN	0301-9268
EISSN	1872-7433
出版年	2021
卷号	352
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.
英文关键词	Egyptian nubian-shield Ra's Abdah, dikes Cryogenian-ediacaran Zircon geochemistry Th-U mineralization
类型	Article
语种	中文
收录类别	SCI-E
WOS记录号	WOS:000600065200016
WOS关键词	CENTRAL EASTERN DESERT ; TRACE-ELEMENT ; PAN-AFRICAN ; CRUSTAL EVOLUTION ; OXIDATION-STATE ; ARABIAN SHIELD ; LU-HF ; URANIUM ; SINAI ; CHEMISTRY
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/348108
作者单位	[Dessouky, Osama K.; Ibrahim, Waleed S.; Ali, Hani H.; Omran, Ali A.; Dardier, Ahmed M.] Nucl Mat Author Egypt, POB 530, Cairo, Egypt; [Sun, Weidong; Li, Congying] Chinese Acad Sci, Ctr Deep Sea Res, Inst Oceanol, Qingdao 266071, Peoples R China; [Sun, Weidong] Qingdao Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao 266237, Peoples R China; [Sun, Weidong] Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China; [Hassan, Mahmoud M.] Suez Canal Univ, Geol Dept, Ismailia, Egypt
推荐引用方式 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],2021,352.
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.
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).