Fluvial architecture of the Upper cretaceous Nubia Sandstones: An ancient example of sandy braided rivers in central Eastern Desert, Egypt

2021 ◽  
pp. 105923
Author(s):  
Zaki A. Abdel-Fattah
2012 ◽  
Vol 62 (1) ◽  
pp. 63-89 ◽  
Author(s):  
Emad Nagm ◽  
Markus Wilmsen

ABSTRACT Nagm, E. and Wilmsen, M. 2012. Late Cenomanian-Turonian (Cretaceous) ammonites from Wadi Qena, central Eastern Desert, Egypt: taxonomy, biostratigraphy and palaeobiogeographic implications. Acta Geologica Polonica, 62 (1), 63-89. Warszawa. In Egypt, marine Upper Cenomanian-Turonian strata are well exposed in the Eastern Desert. The southernmost outcrops are located in the central part of Wadi Qena, where the lower Upper Cretaceous is represented by the fossiliferous Galala and Umm Omeiyid formations. From these strata, numerous ammonites have been collected bed-by-bed and 13 taxa have been identified, which are systematically described herein. Four of them (Euomphalocerascostatum, Vascoceras globosum globosum, Thomasites gongilensis and Pseudotissotia nigeriensis) are recorded from Egypt for the first time. The ammonite ranges are used for a biostratigraphic zonation of the lower Upper Cretaceous succession in the northern and central part of Wadi Qena: the Upper Cenomanian-Lower Turonian has been subdivided into five biozones (including a new upper Lower Turonian biozone based on the occurrence of Pseudotissotia nigeriensis), and one biozone has been recognized in the Upper Turonian. Palaeobiogeographically, the ammonite assemblage has a Tethyan character. During the Early Turonian, influences of the Vascoceratid Province were predominant with strong affinities to typical Nigerian faunas. This shows the significance of faunal exchange between Egypt and Central and West Africa via the Trans-Saharan Seaway. Compared to contemporaneous ammonoid faunas from the northern part of the Eastern Desert, Boreal influences are much less obvious in Wadi Qena. Thus, the present study greatly enhances the knowledge of the Late Cretaceous palaeobiogeography and biostratigraphy of Egypt and adjacent areas.


2016 ◽  
Vol 37 (2) ◽  
pp. 155-189
Author(s):  
H Khalil ◽  
M. S. Fathy ◽  
A. L Abdeldayem ◽  
O. A. Ghobara

2019 ◽  
Author(s):  
Ahmed Abdelaal ◽  
◽  
Mohamed Sultan ◽  
R.V. Krishnamurthy ◽  
Mustafa Kemal Emil ◽  
...  

2014 ◽  
Vol 6 (2) ◽  
pp. 113 ◽  
Author(s):  
Nedal Qaoud

Remote sensing data are used to discriminate between the different lithologies covering the Um Had area, Central Eastern Desert of Egypt. Image processing techniques applied to the Enhanced Thematic Mapper (ETM+) data are used for mapping and discriminating the different basement lithologies of Um Had area. Principal component analysis (PCA), minimum noise fraction (MNF) transform and band rationing techniques provide efficient data for lithological mapping. The study area is underlain by gneisses, ophiolitic melange assemblage (talc-serpentinite, metagabbro, metabasalt), granitic rocks, Dokhan volcanics, Hammamat sediments and felsites. The resulting gray-scale PC2, PC3 and PC4 images are best to clearly discriminate the Hammamat sediments, amphibolites and talc-serpentinites, respectively. The gray-scale MNF3 and MNF4 images easily discriminate the felsites and talc-serpentinites, respectively. The band ratio 5/7 and 4/5 images are able to delineate the talc-serpentinites and Hammamat sediments, respectively. Information collected from gray-scale and false color composite images led to generation of detailed lithologic map of Um Had area.


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