http://depot.umc.edu.dz/handle/123456789/7070 2026-06-01T19:23:23Z http://depot.umc.edu.dz/handle/123456789/14826 Le gisement de fer de Boukhadra (confins-Algérotunisiens) Ait Abdelouahab, Djaouza; Bouzenoune, Azzedine The Boukhadra massif belongs to the north-eastern part of the Saharan Atlas and to the mining district of the diapirs zone. It is a NE-SW orientated anticline characterised by formations of Lower Cretaceous age, cut in its SW part by a NW-SE orientated collapse trough in which Triassic evaporitic formations appear. These played an important role in the structuring of the region and in the emplacement of the Pb-Zn-Fe-Ba mineralisation found there. This work focuses on the carbonated (siderite) and oxidised iron mineralisation at Boukhadra, with the aim of describing and interpreting this type of mineralisation hosted in the Clansayesian limestones. Sedimentologically, the Boukhadra region resembles a barrier platform represented by a standard sequence of 9 microfacies indicating the passage from a frank marine environment (MF1) to a pre-barrier environment (MF2, MF3 and MF4), a barrier (MF5), a back barrier (MF6), then a lagoonal area (MF7) and finally a supratidal zone (MF8) capped by a pre-evaporitic sebkha-type environment (MF9), over an area limited in time and space. Most of the iron mineralisation occurs in the lagoonal facies with miliolae and rudists and in contact with Triassic evaporites, while small quantities of Pb-Zn mineralisation occur after the iron mineralisation and are found in the N-S fractures. The stable isotope geochemistry (C-O-S) carried out on the surrounding limestones, siderites and Triassic sulphates, as well as on a few sulphides, enabled us to define the conditions of deposition, namely that the carbon in the siderites is of mineral origin and that the sulphur originated in the evaporite formations of the Triassic by bacterial or thermochemical reduction. The results obtained at Jebel Boukhadras are comparable with those of the deposits in the diapir zone, both mineralogically and geochemically. These mineralizations are attributed to hydrothermal solutions that may have circulated through faults that acted as drains and favoured locations for Triassic extrusions. These diapiric formations and the Jurassic and Cretaceous cover could also be the source of the iron and lead-zinc elements that gave rise to the deposition of siderite by metasomatosis and the polymetallic veins. The post-Cretaceous periods saw the alteration of both the iron carbonates and the polymetallic veins, thus creating the oxidised mineralisation of the Pliocene period. 2023-11-28T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14822 L’hydrosytème du haut Rhumel à Hammam Grouz dans son cadre régional (hautes plaines du SW Constantinois) Mihoubi, Naouel; Mebarki, Azzedine This research focuses on the Upper Rhumel basin (1130 km2), controlled by the Hammam Grouz dam at Oued Athménia (Constantinois region in eastern Algeria). This basin of the semi-arid High Plains contains three main hydrogeological formations whose lithological and hydrodynamic conditions are varied: the surface layer of the mio-plio-quaternary, the aquifer of the Eocene and the aquifer of the Cretaceous. The cartography from the piezometric measurement campaigns showed a general drainage of the underground system towards the Oued Rhumel and two main directions of flow South West-North East and North East-South West respectively characterizing a convergent layer in the centre and divergent in the extreme West. Chemistry, the study of quality and the ACP have made it possible to highlight a high probability of mixing water and therefore a relationship between the surface aquifer and the deep aquifère (karstic). The Djebel Grouz massif, the site of the dam dyke, contains karst formations that cause remarkable leakage flows to the springs, partly thermal (Hammam Grouz springs), which emerge immediately downstream from the dam. The hydrological functioning of the dam (capacity: 45 hm3), is studied through the monthly and daily regulation balance data of the period 1987-2015, provided by the ANBT (National Agency of Dams and Transfers). These sets of information have made it possible to assess the significant water supply deficit of the basin, resulting in a low rate of annual regulation (30% on average). The variability of the rains and reserves of the Hammam Grouz dam was assessed using the wavelet consistency analysis which showed a correlation between the two signals exceeding 50% (and below 70%) on all modes of variability. Two major events linked to the exceptional rainy inputs of the hydrological years 2002/2003 and 2014/2015 marked the functioning of the system resulting in large volumes of water leakage, hence the appearance of large sinkholes (vortex) within the reservoir. The leakage volumes are estimated on the basis of measurements of the flows from the sources on the one hand, and the abnormal removal of water reserves from the dam on the other hand. The results of the three consecutive years of comparative analysis (2002/2003, 2003/2004 and 2004/2005) of the inputs (or ""tributary"") to the dam with those measured at the gauging station, located upstream, updated the leakage volumes to 7.04 hm3, 32.2 hm3 and 26.2 hm3 respectively. These results show that the leakage rates are much higher than those measured by the ANRH (National Agency for Hydraulic Resources) at the sources of the Hammam, emerging at the bottom of the dyke. Complementary tools and approaches have been implemented for the understanding of the phenomenon of leaks affecting Hammam Grouz: electrical imaging (geoelectric tomography, seismic reflection and seismic refraction), the log of reconnaissance drilling carried out in the dam site, the interpretation of fracturing maps and multivariate analysis of the degree of fracturing of RQD rock. They have made it possible to identify the fracturing-karstification-leakage link of the dam (sources) following the discovery of a fairly dense and complex fracturing network (large faults, corridors, beams, tectonic nodes, etc.), Despite the solutions recommended to preserve the tightness of the basin (injection veil, clogging of vortex), the problem of destocking the Hammam Grouz dam is far from being mastered. It reflects the complexity of setting up hydraulic developments in Constantine karst context. 2023-12-03T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14818 Approche, de la gestion intégrée du littoral et des bassins fluviaux « GILIF » Cemali, Nedjoua; Benazzouz, Mohamed Tahar Like many coastal areas around the world, Skikda coastline is subject to disturbances that threaten its balance at various levels; ecological, sedimentary, sociological, and economic. With 160 km of coastal lineage, a very strong coastal dynamics, and a great conflict of use, Skikda coastline is a complex system at the interface between land and sea. The watershed is a sedimentary source of supply necessary for coastal balance, and any activ ty that contributes to the disruption of this supply will lead to a morphodynamic imbalance. This observation was a starting point for a reflection on the space that must be retained to manage and protect Skikda coastline. The main objective of this disertation is to strengthen geomorphological knowledge in a context based on the link between the watershed and the coastline. In order to achieve this objective, two approaches were used. A systemic approach based on the concept of system, integrating the upper land which is the watershed with the coastline;and a morphodynamic approach that relies on the digital processing of satellite images (Landsat 8) and aerial photographs (1960, 1970, 1988, 2002) through the application of Geographic Information Systems. The results obtained in the two areas studied, which are the Saf-Saf watershed and the mouth, demonstrate a regressive situation of the mouth and its nearby beach L’arbi ben Mhidi. The interpretation and discussion of these results allow to identify the factors that explain this morphological evolution, such as the impact of sedimentary retention at the dam level, deve lopments on the shore, and weather-marine forcing. 2022-07-12T00:00:00Z http://depot.umc.edu.dz/handle/123456789/14812 Étude de la vulnérabilité a la pollution de la nappe alluvionnaire d’el-Milia (nord-est algérien). Bourzama, Abdelhafid; Bouaicha, Foued The most of the Algerian subcoastal regions, especially those in the East of the country, have rugged terrain. The alluvial plain of El-Milia ( study area ) draining oued El-kébir is encased in ""bottom of pan"" by reliefs that surround it on all sides and characterized by a particularly humid climate. In view of the ever-increasing need for groundwater and the overexploitation of the water resources of the surface aquifer contained in El-Milia plain, where intensive agricultural activities in both crops and livestock farming contribute to an already severe pollution of groundwater; these waters, which are subject to industrial pollution, mark the presence of a plant for the production of sanitary ceramics and a tannery and by the recent installation (for a decade) of a colossal steel industry as well as a mega power plant; Faced with all this, the site described is subject to an almost obvious degree of vulnerability, hence the motivated interest in including the present study from a research perspective on the pollution impact on the waters of this free-type aquifer. To do this, it is first necessary to know the geology of the environment and the lithological nature of the aquifer formations that could be behind the chemical face of the waters and especially particular attention is paid to the dosage of heavy metals in order to arrive at the origin of the undesirable elements that are present in this water; the case in which it would be necessary to circumscribe the areas of vulnerability and the ways in which they are protected. 2023-07-20T00:00:00Z