Geological and Structural Studies of Hammamat Sediments; Wadi Abu Hamr Area, Central Eastern Desert, Egypt

Authors

  • Abdelwahab H. Sh. Geology Department, Faculty of Science, Ain Shams University, Egypt.
  • A.H. El Afandy Nuclear Materials Authority, Egypt.
  • A.I. Al Azab Nuclear Materials Authority, Egypt.
  • M.H. Hassan Ahram Canadian University, Egypt.

Keywords:

Wadi Abu Hamr, Structure, Bedding, Ripple Mark, Strike Slip, Metavolcanic, Hammamat, Wadi Safaga, Gebal, Eastern Desert

Abstract

Wadi Abu Hamr area is located between latitudes 26°34', and 26°36'N, and longitude 33° 31' and 33° 46'E, near the northern boundary of the Central Eastern Desert domain. It is characterized by a high rugged topography includes different mountains as Gebel (G.) Um Tagher, G.Abu Furad, G, Wasif, G.Wairah and G.Mohammed Rabah. The exposed rock types in the studied area can be classified as
ultramafic rocks, metagabbros, metavolcanics, quartz diorites and tonalities, Dokhan volcanics, Hammamat Sediments, younger gabbros and monzogranites. The ultramafic rocks crop out in three parts of the studied area; the first one presents as elongated masses, extending NNESW on the northwestern corner of the area, and the other ones crop out as isolated two small masses in the central western part of the mapped area and cut by Wadi Abu Hamr and form hillocks of a moderate relief. The metagabbros are present in the western part of the studied area, and at the end of Wadi Safaga, as well as a small outcrop in the eastern part of the mapped area. The matavolcanic rocks covers the vast region in the central part of the mapped area and characterized by porphyroblastic and amygdaloidal textures. The quartz dioritetonalites crop in the western part of the studied area, and appear at the
western part of Wadi El Pula. The Dokhan volcanics are cropping in the northeastern side of the mapped area. The Hammamat Group sediments well exposed at the east of the central part of the maped area, and occur as an elongated strip, covering an area of about 10km2. The younger gabbros located at the mouth of Wadi Rabah and to the east of Wadi Safaga The monzogranites are located at
the mouth of Wadi Rabah in the north and at the end of Wadi Waeara due south. The studied structures in the area are classified as: bedding geometry, bedding internal structures and gravitational deformation. The laminae thickness exceeds one cm in some outcrops of siltstones. The graded bedding shown in outcrops of sandstones. The crossbedding is of "tabular type" Ripple marks are
excellently exposed in the green siltstones, at the central part of Wadi Safaga. The folds in the study area are recognized as major and mesoscopic scales. The major folds are exposed in parallel, plunging major synclines. The axial traces are oriented in the EW
direction and extends for about 3km. The slaty and crenulation cleavage are recorded in the finegrained tuffaceous metavolcanics, slates, phyllites and schists. The recorded linear structures in the study area are: 1Mineral lineations parallel to fold axes, 2Pencillike
lineations and 3- Boudinage. Strikeslip faults are the most effective type and are encountered in all the rock units with heavy  concentration. These faults are represented as sinistral and dextral senses of movement. Fewer normal faults are also recorded.

Published

2023-04-20