Jebel El Research Articles

Amplified Fragment Length Polymorphism (AFLP) is useful for finding markers associated with QTL for architectural trait in Hedysarum coronarium L.

Amplified fragment length polymorphism (AFLP) has been proposed as a valuable tool for finding molecular markers linked to QTL controlling architectural trait. Segregation of polymorphic AFLP fragments was followed in F2 offsprings Hedysarum coronarium derived from two native wild accesions crossing: Jebel Zit x El Haouaria, which had previously characterised by morphological and AFLP markers. A comparison of profiles from the morphologically contrasted parental individuals and F2 offspring has been assessed using five AFLP primer combinations. These generated 178 bands revealed by silver-stained denaturing polyacrylamide gels, of which 150 were polymorphic. Several AFLP markers appeared to be implied in the orthotropic form that can assist the selection and improve Hedysarum forage crop.

The structure of Jebel El Mourra, Tunisia: a diapiric structure causing a positive gravity anomaly

AbstractDetailed gravity data integrated with geological data and mining well data are analysed to constrain the shape of the Triassic evaporitic body at Jebel El Mourra (northern Tunisian Atlas) and the mechanism of its emplacement at the surface. The gravity data analysis included the construction of a gravity anomaly maps, and synthetic and forward 2.5D gravity models. The complete Bouguer and residual gravity anomaly maps indicate a positive amplitude gravity anomaly over the Triassic evaporitic outcrops and prominent NE–SW‐trending features associated with the boundary of the Triassic rocks and surrounded layers. A NW–SE‐trending gravity model that crosses the Triassic evaporitic outcrop at Jebel El Mourra shows that the positive gravity anomaly can be explained by a deep‐rooted salt diapir. Conventional models of salt dome formation suggest that they produce negative gravity anomalies; however, this study shows that this model is not universal. The studied area is an example of a diapir expressed by positive gravity anomaly and this result is supported by synthetic gravity models at different stages of salt piercing.

Tectonic controls on the petroleum geology of NE Africa

Abstract During the Palaeozoic and early Mesozoic, the NE sector of the African craton remained an entire, integral part of Gondwanaland. It experienced two episodes of intracratonic sagging and marginal cratonic rifting, linked to episodes of strike-slip affecting both the craton interior and its northern margins. Source kerogens accumulated during Palaeotethyan highstands within these sags, across which reservoir clastics prograded during the corresponding lowstands. Such source-reservoir associations are known from the Silurian, Devonian and Carboniferous. The fragmentation of the NE African margin with Mesotethys took place over the period Mid Triassic-Bathonian. From Palestine to Cyrenaica, a rift propagated westwards, detaching crustal terranes along shears that later formed Asia Minor. Deep marine shales within this rift have some proven oil-generating potential. However, the principal Jurassic oil kerogen is found associated with coal swamp-delta clastics, deposited during the Bathonian lowstand, in basins formed between the shears along the new cratonic edge. There is also now evidence for a Mid-Triassic rift penetrating the Sirt Basin from the northwest. Sinistral strike-slip associated with these Mesotethyan shears penetrated deeper into NE Africa during the Late Cretaceous, with subsidence reaching a maximum in the Jebel el Akhdar, Abu Gharadiq and proto-Clysmic Basins, in which rich oil-prone marine source rocks accumulated during the Turonian-Coniacian lowstand. Inversion followed, as the sense of strike-slip reversed with the onset of ‘Syrian Arc’ movements, starting in the latest Cretaceous, and proceeding as a series of pulses into the Late Oligocene. The final phase of ‘Syrian Arc’ tectonics was linked to the opening of the Red Sea and Gulf of Suez Basins, and transtension along the Gulf of Aqaba in the Early Miocene. Falling Miocene sea levels then permitted the accumulation of the restricted ‘Globigerina Marls’ facies within the active graben system of the Gulf of Suez.

Utilisation of Groundwater in Jebel el Akhdar, North-East Libya, as a Basis of Agricultural Improvement with Special Emphasis on the El Marj Plain

AbstractThe critical criteria for regional agricultural development are water and heat. The Jebel el Akhdar region has a semi-arid climate with a marked water shortage except in the winter months. In this paper estimates are made of the runoff which offsets the dry spring and summer and of the storage in the aquifers.The water level records in such regions as El Marj confirm gradual and regular lowering of the water level in the main aquifer. The associated rise of the salt water/fresh water interface is alarming. Great attention must be paid to variation of such storage reservoirs. This situation in the El Marj area is relatively stable compared with other regions of Libya, reflecting the limited demand and relative storage, particularly when water is utilised from the El Gharigh flood.The imbalance in the hydrological basin needs more care in its management and use.

A revision of the Oligocene apes of the Fayum Province, Egypt

AbstractThree years of field excavations in the Oligocene strata of the Fayum Province, Egypt, have yielded more than two dozen new jaws and teeth of fossil apes. This material contributes significantly to our understanding of catarrhine systematics and phylogeny. Here we present a systematic revision of the earliest apes and discuss their relationship with Miocene forms.Two ape species have been recovered from Quarries I and M in the Upper Fossil Wood zone of the Jebel el Qatrani Formation, Aegyptopithecus zeuxis and Propliopithecus (=Aeolopithecus) chirobates. Female Propliopithecus chirobates have small canines which somewhat resemble those of the enigmatic Propliopithecus haeckeli, but have a longer, narrower P3 than the latter. No specimens of either P. haeckeli or Moeripithecus markgrafi have been found in the Upper Fossil Wood zone after ten field seasons, suggesting that these species may occur only lower in the section.Aegyptopithecus and Propliopithecus have no shared derived features that exclude them from the ancestry either of Old World monkeys or apes. Thus, Aegyptopithecus, the better known form, is suitably primitive to have been the ancestor of all later Old World monkeys and apes (and hominids). The possibility of a separate gibbon or hominid lineage going back to the Oligocene is unlikely on present evidence.

Affinities and palaeobiogeographic significanceof the Mongolian Paleogene genus Phenacolophus

Additional material has increased our knowledgeof the morphology of the poorly known ungulate genus Phenacolophus from the Paleocene and (?) earliest Eocene of eastern Asia. Herein we regard Phenacolophus as a primitive arsinoithere on the basis of derived characters shared with Arsinoitherium from the early Oligocene Jebel el Qatrani Formation of Africa and Crivadiatherium from the late Eocene or Oligocene of the southern Carpathians Mountains of Romania.

Environment and the Structure of Scrub Communities on the Limestone Plateaux of Northern Cyrenaica

Between the desert lowlands of Egypt and Tripolitania and the wastes of the Libyan 'sand sea', the stepped plateaux of the Jebel el Akhdar of Cyrenaica project, island-like, into the Mediterranean. This area is of outstanding botanical interest, owing partly to its altitude, exceeding 2000 ft. (610 m.) in places, and partly to a geographical isolation almost as effective as that of an island, resulting from the extension of the Libyan desert up to the coast at Agedabia in the west and Tobruk in the east (see map, Fig. 1). It was visited in September 1951, during the first 'phase' of the Aberdeen University Expedition to Cyrenaica.* The expedition was primarily geographical in character, being led by Dr W. B. Fisher (Lecturer in the Department of Geography), and while in this region its main objective was to carry out surveys relating to geomorphology, land utilization and water economy in the neighbourhoods of Derna and Cyrene (Fisher, 1952). The botanical contribution to this end was the comparison of the various communities encountered, in terms of their perennial components which form the permanent structural framework of the vegetation. As far as the short time permitted, evidence of their origins or relationships, and information regarding the effects of certain environmental influences, were sought. Among features of interest in the flora of this area is the fact that its geographical affinities lie mainly with the east Mediterranean (Palestine to Greece) rather than with neighbouring parts of North Africa, and particularly striking are numerous floristic links with Crete (Sandwith & Simpson, 1941). Rikli (1943-8) describes the geographical distri-

New Light on Endor

Khirbet es Safsafeh was occupied during the Early, Middle and Late Bronze Age and flourishe<;lduring the Israelite period, from the time of the settlement of the tribes up to and during the days of the monarchy. During the Exile the place was abandoned, and was again occupied from the first century A.D. till the eight century A.D. During all these periods the site was an agricultural settlement but also a strongpoint on the route connecting Galilee and Gilead with Ephraim and Judah. It may be supposed that the name Endor was transferred by the villagers when they moved to a new location on the slope of Jebel el Jurus, 1 km. away, in the hope that the name would protect them.There are many places in Palestine where the ancient name was transferred by the Arabs from the original site, to a new one: Cp. the transferring of the name ‘Gezer’ to ‘al Jizri,’ or ‘Eglon’ to ‘Sheikh Ajlan’ or ‘Rehob’, in the Beisan valley to Sheikh er Rihab one mile south of Tell es Sarim.