Structural elements and incremental strain history of the basement rocks of Um Had area, central Eastern Desert, Egypt

Abstract

The Um Had area, central Eastern Desert, Egypt shows a regional stretching in the NW-SE and a contraction in the NE-SW direction. Major NW-SE folds, small recumbent folds, and local thrusts and reverse faults were recognized. Complicated relation between folds and boudinage was identified. This stretching amount ranges from 1.282 to 1.309. Earlier coaxial and later non-coaxial strains were inferred. The change from axial to non-coaxial stress regime was gradual and the latter was associated with minor clockwise and anticlockwise rotation of structural elements. During the non-coaxial strain, strain fringes were formed as a consequence of the high circulation of fluids in low temperature and high pressure conditions. Superimposed strain fringes indicating right-and left-lateral senses of movement were recognized. At least three generations of fringes were recognized, implying three stages of non-coaxial stretching. Each generation has about 15 increments which show irregular strain gradient and intensity over the different increments. Eastwards, the strain increments became mature and westwards, the finite strain increases. The strongest finite strain was found in a narrow belt delimiting the basement rocks on the west and underlying the Phanerozoic sediments. Chocolate-tablet structure was recorded and indicates later multidirectional tension. Not all Nubia Sandstone exposures are overlying the basement rocks and some are separated by NW-SE normal faults. Major NW-SE normal faults are cutting basement rocks of different ages.

Delineation potential gold mineralization zones in a part of Central Eastern Desert, Egypt using Airborne Magnetic and Radiometric data

“…Abd El Rahim et al (2013) studied Gold-bearing sulfides associated with the granitic wall rock alterations at the Fawakhir area. Akawy (2009), studied the Structural elements and incremental strain history of the basement rocks of Um Had area. Abd El Nabi (2013), clarify the Role of x-ray spectrometry in detecting potassic alteration associated with Um Ba'anib granitic gneiss and metasediments, G. Meatiq area.…”

Phytosociological Studies on the Associated Species of Balanites aegyptiaca In The Eastern and Western Egyptian Deserts

“…The washes that drain the desert into the Red Sea cut through this basement ridge as well as the sedimentary succession to the east (Said 1962). There have been few geomorphological investigations on Wadi El-Gemal, but the most significant ones are those by El-Sharkawi et al (1982), Hegazy (1984), Akawy (1999), Ahmed (2001), Barakat (2003), Khaleal et al (2005) and Tarek & Fahmy (2012). Wadi El-Gemal and its tributaries make up the main valley, and each of them has numerous tributaries.…”

Egyptian Hammamat molasse basins and their relations to arc collision stages: Implications for radioactive elements mineralization potential

“…HMSR fringe eastward the ophiolitic mélange with no definite contact. One of the most significant examples of contact aureole as a result of the intrusion of the late‐collision granites into HMSR is that of Um Had area (Akawy, ; Dardier, ; El Kalioubi, ). The thermal metamorphism affected HMSR producing successive zones of different significant lithological facies decreasing in grade of metamorphism outwards.…”

“…The polymictic conglomerates are represented by ill-sorted boulders, pebbles, granules, and sandy-sized grains that ranging in size from 1 mm up to 65 cm across embedded in a fine matrix, which contains fine scales of sericite, quartz, and iron oxides. granites into HMSR is that of Um Had area (Akawy, 2009;Dardier, 1994;El Kalioubi, 1988). The thermal metamorphism affected HMSR producing successive zones of different significant lithological facies decreasing in grade of metamorphism outwards.…”