LOSS OF GEODIVERSITY


to the human impact on the natural reserves in the world, the creation of Protected Areas appears as a funda- mental tool used worldwide for creat- ing a buffer and refuge against the rising tide of anthropogenic impacts. The first nature reserve in modern his- tory was established in 1821 at Walton Hall, West Yorkshire, England by the naturalist Charles Waterton. The first state designated nature reserve was in modern day Germany when in 1836 the hill of Drachenfels was bought by the Prussian state to prevent further quarrying damage to the igneous rocks. The first major reserve was Yellowstone in Wyoming, USA designated in 1872 (https://en.wikipedia.org/wiki/Nature_ reserve. Accessed 2017/11/17). Today, there are 114,000 protected areas around the world in almost every coun- try, covering nearly 12% of the world’s land surface (http://www.motherjones. com/politics/2012/04/protected-planet/#. Accessed 2017/11/17). In addition to preserving outstanding examples of natural habitats and providing refuges for endangered species of plants and animals, geologic and geomorphologic features, they also play an increasingly important role in social and economic development.


The use of protected areas has been widely adopted in Egypt and is the responsibility of the Ministry of State for Environmental Affairs (MSEA) and its executive arm, the Egyptian Environmental Affairs Agency (EEAA). They consider nature conservation criti- cal to the national environmental strat- egy. Law 102 of 1983 provides the legislative frame-work for establishing and managing protected areas in Egypt. Protected areas are defined as “any area of land or coastal or inland water characterized by special flora, fauna and natural features having cultural, scien- tific, tourism or aesthetic value.” With growing awareness of the importance of managing resource use to sustain devel- opment, as well as awareness of rapid environmental degradation, increased attention was given to environmental protection. The EEAA was restructured in 1992 and Law 4 of 1994 became the primary legislation for environmen- tal management, creating the Nature Conservation Sector for management of Egypt’s Protected Areas.


The Protected Areas in Egypt cover 10% of its area; there are more than 24 such areas distributed all over the country. They include land and marine areas comprising a representative range


www.aipg.org


of habitats and physiographic regions, along with other sites of importance such as biodiversity hotspots, cultural heritage sites, geological formations and landscapes of outstanding natural beau- ty. Bahriya and Farafra Oases are listed in the protected areas in Egypt due to the varieties of geosites found within them.


II. Lithology and


depositional environment of Bahariya and Farafra Oases:


a. Lithology:


The Bahariya Formation includes the lowest and the oldest exposed beds in the Bahariya Oasis. It forms the floor of the oasis and the basal part of the surround- ing scarps (Section 1). The base of the


(Soliman and Khalifa, 1993). In the northern parts of the Oasis, two distinct units are recognized, i.e. a lower unit consisting of siltstones and mudstones with plant remains, and an upper unit composed of glauconitic claystones with thin ferricrete interbeds. The correla- tion of these units is based primarily on lithological grounds (Soliman and Khalifa, 1993).


Catuneanu et al., (2006) stated that the Bahariya Formation itself is an unconformity bounded depositional sequence which corresponds to a major stratigraphic cycle (El Bassyouny, 1970) in the evolution of the passive margin setting of the Western Desert. The entire package of passive margin deposits cor- responds to a first-order sequence, as being related to one distinct tectonic set- ting. Hence, according to the hierarchy system based on the magnitude of base- level changes that resulted in the forma- tion of the sequence (Embry, 1995), the Bahariya Formation can be assigned a second-order level of stratigraphic cyclic- ity. In this context, the four depositional sequences which form its stratigraphic subdivisions, may be regarded as third- order sequences.


b. Paleoenvironment:


Section 1: Stratigraphic column after Metwalli and Pigott, 2005.


Bahariya Formation is unexposed, but is inferred to be unconformable at the contact with the underlying basement (El Bassyouny, 1970), while its top shows an unconformable relationship with the overlying Upper Cenomanian El Heiz Formation (Khalifa and Abu El-Hassan, 1993), or the Lower–Middle Eocene El-Naqb Formation (El Bassyouny, 1970, 2004). The exposed thickness of the Formation ranges from c. 90 m in the central part of the Oasis, to over 100 m in the northern sections.


From a lithological point of view, the Bahariya Formation exhibits significant lateral and vertical changes of facies. In the central parts of the Oasis, the Formation consists of three informal lithologic units defined by interbedded siltstones and sandstones (lower unit), crossbedded amalgamated sandstone bodies (middle unit) and dark colored ferruginous sandstones (upper unit)


Early Tertiary deposition in the Western Desert of Egypt appears to have consisted of filling of basins devel- oped on a pre-Tertiary topography made up of eroded anticlinal and synclinal structures with a general east or north- east trend (Shata, 1953; Bayoumi and El Gamili, 1970). Folding that pro- duced these structures probably began in the Middle Cretaceous (Shata, 1953), but continued sporadically through the Tertiary (Shata, 1953). Therefore, the thicknesses of early Tertiary rocks in the Fayum Depression as well as in the rest of the Western Desert of Egypt vary considerably, being thinnest across the tops of active buried structural highs and thickest in the intervening structural depressions.


A tensional tectonic episode is record- ed in later Oligocene times by north- west-trending normal faults at Jebel Abu Roash and throughout the north- ern parts of the Eastern and Western Deserts of Egypt. At several times dur- ing the later early Oligocene, basaltic lavas were extruded from these fissures across the erosional surface developed on the Jebel Qatrani Formation and other rocks over a wide area from the Gulf of Suez to the Fayum Depression, and perhaps as far west as the Bahariya Oasis. Rittmann (1954) believed that


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