The late Neoproterozoic Pan-African low-grade metamorphic ophiolitic and island-arc assemblages at Gebel Zabara area, Central Eastern Desert, Egypt: Petrogenesis and remote sensing - Based geologic mapping

2018 ◽  
Vol 144 ◽  
pp. 17-40 ◽  
Author(s):  
Mohamed W. Ali-Bik ◽  
Safaa M. Hassan ◽  
Moustafa A. Abou El Maaty ◽  
Said H. Abd El Rahim ◽  
Salwa D. Abayazeed ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Eastern Desert ◽  
Island Arc ◽  
Low Grade ◽  
Geologic Mapping ◽  
Central Eastern Desert ◽  
Pan African ◽  
Central Eastern ◽  
Late Neoproterozoic

scholarly journals Geochemistry of Umm Rus gold - quartz veins, Central Eastern Desert Egypt. A new contribution

2001 ◽  
Vol 34 (3) ◽  
pp. 1139
Author(s):  
O. A. KAMEL ◽  
M. M. EL MAHALLAWI ◽  
H. M. HELMY
Keyword(s):  
Hybrid Zone ◽  
Eastern Desert ◽  
Quartz Diorite ◽  
Low Grade ◽  
Gold Content ◽  
Strongly Correlated ◽  
Quartz Veins ◽  
Central Eastern Desert ◽  
Pan African ◽  
Gold Bearing

Gold-bearing quartz veins of the Umm Rus area occur at the south-eastern contact of a Precambrian granodiorite cupola within younger gabbros of 573-615 Ma belonging to the Pan African orogenic belt. The rocks are intruded within low-grade metasediments. At such contact, a hybrid zone is developed characterized by the occurrence of quartz diorite which grades into diorite and meta-ferrogabro. A limited number of mineralized quartz veins cut the granodiorite-gabbro complex. Different alteration zones are developed in the vicinity of the quartz veins. The quartz veins have two main trends; NS and N30 E, the latter one is usaually gold-bearing. The mineralized parts of the veins commonly consist of highly sheared and banded smoky quartz, and the gold content depends on the relation with the dykes. The element is strongly correlated with As and Ag, but moderately with Cu. Near to intermediate and basic dykes, the contents of Au, Ag and As are noticably increased

scholarly journals Geochemistry of the Um Had Plutonites, Central Eastern Desert, Egypt: Implications for Magma Evolution, and Tectonic Setting

2014 ◽  
Vol 6 (2) ◽  
pp. 36 ◽  
Author(s):  
Nedal Qaoud
Keyword(s):  
Tectonic Setting ◽  
Active Continental Margin ◽  
Eastern Desert ◽  
Island Arc ◽  
Water Vapour Pressure ◽  
Calc Alkaline ◽  
Magma Evolution ◽  
Basement Complex ◽  
Central Eastern Desert ◽  
Pan African

Geochemistry of gabbroid and granitoid plutonites from the Um Had area indicates island arc subalkaline basic magma with tholeiitic affinity and calc-alkaline, metaluminous and slightly peraluminous magma, respectively. Although different in age both plutonite types were emplaced under compressional regime, where subduction-related environment was dominant. They were formed under relatively low to moderate water-vapour pressure (1–5 k-bars) at moderate depths (20–30 km). Biotite granites were formed at a relatively high temperature range (800–840 °C), while biotite-muscovite granites were formed under relatively moderate temperature conditions (760–800 °C). These two units may represent evolution from island arc to active continental margin. It is suggested that island arc gabbros might have sourced the late subduction-related calc-alkaline granitoids during the waning stages of the pan-African orogeny. The I-type nature of the investigated plutonites in the study area and elsewhere suggests the juvenile character of the basement complex of the Eastern Desert of Egypt.

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