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Monazite and cassiterite Usingle bondPb dating of the Abu Dabbab rare-metal granite, Egypt: Late Cryogenian metalliferous granite magmatism in the Arabian-Nubian Shield

April 13, 2020

The Abu Dabbab rare-metal granite in the Eastern Desert of Egypt is a highly-evolved alkali-feldspar granite with transitional magmatic-hydrothermal features. Extreme geochemical fractionation and the associated significant TaSn resource make the Abu Dabbab intrusion an important feature in the metallogenic evolution of the Arabian-Nubian Shield. UPb dating by laser ablation sector field (SF)-ICPMS analysis of igneous monazite yields a Concordia age of 644.7 ± 2.3 Ma, identical within uncertainty to a lower intercept Tera-Wasserburg isochron age of 644.2 ± 2.3 Ma obtained from hydrothermal cassiterite. Both ages place tight constraints on the timing of magmatic-hydrothermal processes in the Abu Dabbab granite which represents the oldest highly-evolved granite recognized so far in the Pan-African Arabian-Nubian Shield. Thus, the new ages also date the start of a period of late-orogenic metalliferous granite magmatism, when the basement of the Eastern Desert underwent a geodynamic transition from a compressive subduction-collision regime towards orogenic collapse in the late Cryogenian.

Citation Information

Publication Year 2020
Title Monazite and cassiterite Usingle bondPb dating of the Abu Dabbab rare-metal granite, Egypt: Late Cryogenian metalliferous granite magmatism in the Arabian-Nubian Shield
DOI 10.1016/j.gr.2020.03.001
Authors Bernd Lehmann, Basem Zoheir, Leonid A. Neymark, Armin Zeh, Ashraf Emam, Abdelhady Radwan, Rongqing Zhang, Richard J. Moscati
Publication Type Article
Publication Subtype Journal Article
Series Title Gondwana Research
Index ID 70219427
Record Source USGS Publications Warehouse
USGS Organization Central Mineral and Environmental Resources Science Center; Crustal Geophysics and Geochemistry Science Center; Geology, Geophysics, and Geochemistry Science Center