History of Mineral Exploration and Exploitation of the Egyptian Nubian Shield

The Nubian Shield rocks in Egypt pertain to the Precambrian only. Mesozoic and Cenozoic intrusives and extrusives are excluded. The age ranges between 1000 and 550 my, i.e., Neoproterozoic. The main target for the shield exploration is the Eastern Desert, the southern part of Sinai and sporadic outcrops in the southern part of the Western Desert. Human started to live in communities especially on the Nile River banks, and searched for certain commodities, the colored ones first followed by gold. Official expeditions were sent to the wild deserts guarded, as they believe, by their beloved deities. The record is fortunately inscribed on the walls to unravel the history of mineral exploration and exploitation during the ancient times. The Egyptian Nubian Shield (ENS) is not only that exposed to the surface but also the Precambrian rocks under the Phanerozoic cover. The nature of the hidden rocks is currently disclosed from the deep oil exploration wells which bottomed in the crystalline rocks. This term is used by the oil geologists for the subsurface igneous and metamorphic rocks. It is fortunate that in Egypt, the Precambrian rocks, act as reservoir rocks for oil in certain places. In the Gulf of Suez oil is seeping from fractured granitic rocks in Gebel El Zeit area. Suez Oil Company is tapping oil from subsurface fractured granitic rocks in Zeit Bay and Megawish Petroleum Company from fractured rhyolitic rocks, north of Hurghada. The nature of the hidden “basement rocks” is sporadically known. Nashfa area west of El Minya is a high granitic basement, encountered in depth to about 600 m. In the vicinity of Assiut, at about 3 km depth mylonitic rocks are encountered and in the subsurface of Matruh basin gneisses prevail. The subsurface data are hosted at the Egyptian Petroleum Organization. The nature of the hidden Precambrian rocks in Libya and Algeria based on the drilled oil wells (Schurmann, The Pre-Cambrian in North Africa, E.J, Brill, Leiden, 1974). These rocks were compared with those exposed in Egypt and Saudi Arabia. It is worthy to mention that basement rocks is a vague term, and in Egypt is considered as Precambrian rocks. This term worldwide is applied to any rocks of any age below the target area in exploration. It is advisable to divide the ENS into northern, central, and southern (Fig. 14.1). The northern includes the Red Sea hills north of Safaga-Qena stretch, and extends to include south Sinai and south Jordan. The central is down to latitude 24 N and the southern is down to latitude 22 N. Gold is rare or nonpresent in the northern part of the ENS, but common in the central and southern parts. Could be the absence or rare occurrence of ultramafic and ophiolitic rocks from the northern sector is the cause? Open image in new window Fig. 14.1 General geology of the Nubian Shield in Egypt, simplified after Stern and Hedge (1985)