The Bir Haddada Plain is located in eastern Algeria and is characterized by a semi-arid climate with low rainfall. The irrigation of this region's agricultural lands is almost assured by hundreds of wells that exploit the shallow aquifer. The strong pumping of the shallow aquifer triggered the latter's utter exhaustion. To resolve the irrigation water shortage, we need to explore the subsoils to find potentially exploitable aquifers more closely. The objective is the geoelectric characterization of this area and also the detection of underground water aquifers. The geophysical study by vertical electrical survey (VES) is more adequate because it allows identifying the conductive and resistant layers to the electric field. Exploration by VES was carried out with a spacing of the measuring electrodes ranging from AB = 100 to AB = 1000 m. The study of the results obtained indicates that the prospective zone is distinguished by a filling exceeding 300 m corresponding to the miopliocene formations. These formations are generally clays, conglomerates, and lacustrine limestones. In contrast, the low resistivity values seem to be related to the presence of conductive formations such as Miopliocene gypsum clays or to the presence of Triassic rocks linked to the contact of the bedrock. The maps of the apparent resistivity often show a network of different direction faults.
The aquifers in the M’léta Plain are crucial for supplying drinking water and supporting industrial and agricultural water needs. However, they are facing a pollution risk and environmental degradation. The present study aims to assess the groundwater quality in the M’léta Plain, focusing on its physicochemical properties, statistics of the aquifer, pollution risks, and factors influencing the water mineralisation process. The analysis of 16 samples reveals that the water contains high levels of sulphates and chlorides, often accompanied by sodium, calcium, or magnesium. This suggests two distinct water types or facies: one characterised by sodium chloride or calcium chloride, and the other with calcic or sodic sulphate waters, sometimes including magnesium sulphate. These facies may be attributed to the influence of different formations at the outcrop. Statistical analyses reveal a strong correlation between electrical conductivity and the majority of chemical elements, indicating the impact of freshwater interacting with the underlying rock formations on mineralisation. Some results also show undersaturation of certain minerals. Furthermore, the study evaluates the water's suitability for irrigation in the M’léta Plain in accordance with Richards’ classification.
L’aquifère de Hammam Bradaa se situe au Nord-Est de Guelma à l’Est algérien. Il fait partie du bassin versant de la Seybouse et plus précisément le sous bassin de la moyenne Seybouse qui couvre une superficie de 820 km2. Du point de vue géologique, les formations rencontrées sont en majeure partie carbonatées d’âge Crétacé, avec une couverture récente hétérogène (remplissage d’âge tertiaire). L’objectif est l’identification de la qualité des eaux par l’outil statistique pour ressortir les tendances et par conséquent les groupes chimiques qui caractérisent les eaux de la nappe profonde de Hammam Bradaa. Tout d’abord, l’estimation du coefficient de variation (CV%) indique que la majorité des mesures liées à chaque variable se rapprochent de la moyenne et ne montre pas une grande dispersion, contrairement aux mesures des nitrates qui présentent une grande dispersion autour de la moyenne, ceci peut être expliqué par l’utilisation sélective des engrais chimiques pour l’agriculture des terres exploitées. Par ailleurs, la corrélation simple (matrice de corrélation) et multiple (ACP et C.A.H), mettent en évidence des liens significatifs entre les ions issus de la dissolution des minéraux carbonatés (Mg et HCO3) ainsi que ceux résultants des minéraux évaporitiques (Na et Cl). La conductivité électrique n’indique pas une bonne corrélation avec les ions témoignant ainsi de la faible minéralisation des eaux étudiées. Nous remarquons la bonne concordance entre les résultats de l’analyse statistique et ceux de l’interprétation hydro chimique.
Several hydrologists recently stated that a large portion of the world’s population will face “water stress” in the coming years due to a variety of factors, including global mismanagement of fresh water near coastal plains, which is still being ignored and has become polluted. The alluvial plain of Wadi El Nil is one of these coastal plains, located in one of the wettest regions of Algeria with an annual rainfall rate of around 1000 mm. To quantify and qualify the water potential and to design a water management policy, a study was conducted using a complex of tools, such as geological, geophysical by electrical methods, hydro-climatic, and hydrogeological, to determine the lithology, geometry, and hydrodynamic characteristics of the aquifer.
The stratigraphical features and palaeoenvironmental conditions of the upper Cenomanian–lower Coniacian carbonates from the northern part of the Aures Range are described for the first time. Four formations have been recognised, namely the Arris, Adahri, Yabous, and Bou Ouali, respectively. Planktonic foraminifera enable us to assign the upper part of the Arris Formation and the lower part of the Adahri Formation to the Middle–Upper Cenomanian (Rotalipora sp. cf. R. cushmani Total Range Zone), the upper part of the Adahri Formation to the Cenomanian–Turonian Transition to the lower Turonian (Whiteinella archaeocretacea Partial Range Zone and Helvetoglobotruncana helvetica Total-Range Zone, respectively), the lower member of the Yabous Formation to the middle Turonian (Marginotruncana sigali Partial Range Zone), and the upper member of the Yabous Formation to the upper Turonian (Marginotruncana schneegansi Partial Range Zone). The Turonian–Coniancian boundary was dated approximately. This biozonation enables a correlation with several upper Cenomanian–lower Coniacian sections outside Algeria, mainly within the Tethyan and Boreal domains. Based on the field data, and microfacies studies, the strata of these formations are arranged into eleven microfacies types (MT 1 to MT 11) that are described in terms of depositional environments, and grouped into three main facies associations (FA 1, FA 2, and FA 3): (i) a deep shelf-basin facies zone; (ii) marginal sand shoals, an open-marine/restricted platform facies zone; and (iii) an outer platform and toe-of-slope/distal slope facies zone. Analysis of the sequence stratigraphy has allowed the recognition of three third-order depositional sequences grouped into two megasequences and correlated to a regional scale.
The thiolliericrinids, although having a stem in the adult stage, are classified as comatulids (Comatulida) that are usually identified as stemless forms. They first appeared in the Bajocian (Middle Jurassic), and their last occurrence is noted in the Hauterivian (Early Cretaceous). Herein we report a thiolliericrinid crinoid from the Aptian of northern Africa (Algeria). This is the youngest thiolliericrinid crinoid ever recorded. Previously, the youngest thiolliericrinid (Thiolliericrinus) came from the Hauterivian (Lower Cretaceous) of France, Germany, Portugal, and Switzerland. This youngest thiolliericrinid has a smooth and irregular centrodorsal with no cirrus socket. The radials are irregular; some of them are variable in size and display no visible basal plates externally. The latter feature is typical of evolutionarily advanced Early Cretaceous thiolliericrinids (e.g., Heberticrinus or Loriolicrinus). Additionally, the present record is also the only representative of thiolliericrinids with a cup strongly oblique on the stem.
This research delves into the geological features of the western section of the Aures Basin, with a primary focus on Djebel Metlili. The geological characteristics span Mesozoic and Tertiary deposits, ranging from the Triassic to the Quaternary epochs. Notably, the higher Cretaceous period stands out for its substantial carbonate-rich sequence. The research relied on geological maps, field observations, core samples, and laboratory analyses, including lithostratigraphic examinations (cross-section) and thin section. Structural features show that is formed by large regular folds of ENE-WSW or E-W direction. Anticlines and synclines are often affected by transverse accidents at the axes of the folds. In its northern part is located immediately south of the Belezma-Batna mountains. Structural analysis highlights significant tectonic disturbances, oriented in a northwest-southeast direction. A detailed lithostratigraphic examination reveals marly formations interspersed with limestone-rich layers containing Inoceramus. The southern part of Dj. Metlili, particularly the Santonian-Campanian series, unveils three distinct meso-transgressive sequences, linked to sea-level fluctuations associated with sedimentary basin subsidence. The studied area exhibits three distinct facies: one characterized by gray phosphate limestone with crisscrossed stratifications and agitated bioclastic sand, another featuring a mollusk-rich bioclastic limestone indicating a turbulent intertidal environment, and a third presenting a clay limestone bank with fine to medium grains and lumachels rich in oysters and gastropods. The associated grainstone texture in the microfacies suggests an internal platform environment marked by dissolution, bioturbation, and ferruginization. This comprehensive exploration provides valuable insights into the geological history of the region, significantly contributing to our understanding of its evolution over time.
The stratigraphic problem of the Jurassic-Cretaceous boundary (JKB) is still the object of a warm international debate. Around this limit, the Upper Tithonian substage has been the subject of significant stratigraphic investigations throughout the Tethyan Realm areas. On the southern Tethys Margin of the Maghreb, our recent works in NE Algeria have revealed sections, where good Upper Jurassic outcrops are considered as promising for the definition of a Global Standard Section and Point (GSSP) for the Jurassic-Ctretaceous boundary. In this line of interest, a high resolution calpionellid biozonation of Upper Tithonian successions from two bed-by-bed sampled key sections in the Aurès (Jebel Azreg) and Aïn Yaghout Mounts (Jebel Toumbaït) of NE Algeria is proposed here for the first time. The Crassicollaria and Calpionella Zone limits, encasing two subzones and six stratigraphic horizons, are identified. Within these sections, calpionellid distribution and resulting biostratigraphic units fit the standards referred to for the Tethyan Realm. The identified marker bioevents and associations confirm the high biostratigraphic potential of calpionellids for the JKB definition in the North Africa Maghrebian Chains. Correlation transects reveal important thickness and facies variations interpreted as the result of a synsedimentary tectonic control implying NW–SE, E-W and NE-SW major faults that led to the individualization of a mozaic of highs and depressions where Upper Tithonian deposits onset. A proposed interpretative model replaces the Upper Tithonian study successions in their regional geodynamic context.
The deterioration of the physico-chemical quality of surface waters in the Algerian Northeast is caused by several factors. Our study aims to fill the knowledge gap on the control of hydro-chemical evolution of surface waters in wetlands. The main focus is on major elements in surface waters of the Skikda region in northeastern Algeria. To address this issue, we received 45 samples during the 09 campaigns conducted during the period of low and high water of the year 2015-2016, distributed over five points, namely the tributary Oued Khemakhem, Oued Bouadjeb, Oued Safsaf, reservoir of the Zerdazas dam and the downstream of the Zerdazas dam. First, we studied the variation of physical elements such as pH and EC. Then, using PCA and FA, we characterized the physicochemical properties of the water to demonstrate the relationship between the elements and the factors controlling the distribution of the major elements and the heavy metals Pb2+, Fe2+ and Sr2+. The specific formula of the dominance of the different concentrations in the surface waters of the study area followed the sequence: Ca-Mg-Na-K and Cl-SO4-HCO3 from which a predominant specific facies emerges on 67% of the samples, is of the chloride and sulfate-calco Magnesian facies.
Lacustrine depositional systems provide a valuable record of palaeoenvironmental conditions since they rely on a delicate balance between accommodation space and water-sediment supply controlled by tectonic activity and climatic conditions. This study presents new sedimentological and micropalaeontological information from the early Miocene lacustrine Oued Tilatou Formation, northeastern Algeria. Based on sedimentary facies and microfossil assemblages, the Oued Tilatou Formation (OTF) is divided into two discrete units, the Lower OTF and the Upper OTF. The Lower OTF is characterised by reddish clay-rich carbonate mudstone containing reworked foraminifera and ostracods interspersed by polymodal clast-supported conglomerates attributed to alluvial deposition. The Lower OTF was deposited under fluvial–palustrine conditions, marked by a notable terrigenous sediment influx. In contrast, the Upper OTF encompasses greenish charophyte-dominated (Sphaerochara sp.) carbonate mudstone interbedded with silty carbonate mudstone, and dolomitic wackestone containing charophyte thalli, several ostracod species, and stromatolites. The dominant ostracod taxa within this interval are Mediocypris sp. cf. M. candonaeformis, indicating freshwater–brackish water conditions. The transition in depositional facies from the Lower OTF to the Upper OTF is interpreted as reflecting changes in the environment from fluvial–palustrine to shallow water lacustrine with fluctuation in freshwater input during the Burdigalian (Early Miocene). This study provides new insights on the interplay between early Miocene climate conditions and the tectonic uplift of the Aurès Massif, and their implications for lacustrine palaeoenvironmental conditions.
The deterioration of the physico-chemical quality of surface waters in the Algerian Northeast is caused by several factors. Our study aims to fill the knowledge gap on the control of hydro-chemical evolution of surface waters in wetlands. The main focus is on major elements in surface waters of the Skikda region in northeastern Algeria. To address this issue, we received 45 samples during the 09 campaigns conducted during the period of low and high water of the year 2015-2016, distributed over five points, namely the tributary Oued Khemakhem, Oued Bouadjeb, Oued Safsaf, reservoir of the Zerdazas dam and the downstream of the Zerdazas dam. First, we studied the variation of physical elements such as pH and EC. Then, using PCA and FA, we characterized the physicochemical properties of the water to demonstrate the relationship between the elements and the factors controlling the distribution of the major elements and the heavy metals Pb2+, Fe2+ and Sr2+. The specific formula of the dominance of the different concentrations in the surface waters of the study area followed the sequence: Ca-Mg-Na-K and Cl-SO4-HCO3 from which a predominant specific facies emerges on 67% of the samples, is of the chloride and sulfate-calco Magnesian facies.
Water resources are facing significant challenges in result of rapidly growing demand, deteriorating quality, and the effects of climate change. Today, water quantity and quality issues have become prevalent in various regions across the globe, affecting both northern and southern territories. Among the sectors reliant on this resource, irrigation stands out as the largest consumer of water. When surface water becomes inaccessible due to insufficient precipitation or other factors, the use of groundwater becomes the only viable alternative for irrigation. The Remila Plain (Khenchela) is located in an endorean watershed in northeastern Algeria and extends over 250 km2 in a synclinal basin filled with water from the Mio-Plio Quaternary - the main aquifer of the region, widely used for irrigation. The aim of this work is to study the hydrochemistry of these waters, as well as the evolution of mineralisation, the identification of the origin of the chemistry, and the suitability of these waters for irrigation. Initial results indicate an evolution of mineralisation in the direction of groundwater flow, with electrical conductivity values varying between 1000μS/cm in the recharge zones, and 2700μS/cm at the outlet. This mineralisation is mainly due to the dissolution of evaporitic minerals and the alteration of silicates. In addition, the various water quality indices used indicate that the water can be used for irrigation without major risk to plants and soils.
Understanding the processes controlling groundwater mineralization is critical for preserving its quality and ensuring sustainable resource management, especially in regions like Naama, Algeria, which rely exclusively on groundwater. T his resource faces severe overexploitation and high salinity due to climatic factors and increasing industrial, agricul tural, and domestic demands, posing significant challenges to its long-term usability. Hydrochemical analyses, inclu ding graphical methods and multivariate statistical tools, were employed to investigate the groundwater chemistry and mechanisms influencing mineralization in the Naama region. The results revealed a relatively homogeneous distribu tion of groundwater samples, categorized into three hydrochemical groups. These groups are primarily dominated by calcium and magnesium chloride and sulfate waters, influenced by the geological characteristics of the region, such as gypsum-saline formations of the Upper Cretaceous and Triassic clay-gypsum-saline diapirs, and further impacted by inverse ion exchange processes. Group 1 is characterized by higher proportions of calcium and magnesium bicarbo nate waters due to the dominance of carbonate formations from the Early Jurassic or Miocene, benefiting from more dynamic recharge zones. Groups 2 and 3 exhibit similar chemical compositions, but Group 3 is distinct for its restricted recharge zones and carbonate formations, leading to the emergence of calcium and magnesium bicarbonate waters. Recharge areas associated with carbonate formations were also vulnerable to anthropogenic pollution. These findings highlight the importance of implementing strict protection measures for sensitive recharge zones to ensure the preser vation of this vital resource in the face of increasing environmental and human pressures.
