Characterizations and Potential Recovery Pathways of Phosphate Mines Waste Rocks

The Phosphate Ore Production is Steadily Increasing Due to its High Demand for Agriculture, Medicine, and Others. Ore Extraction Generates a Considerable Quantity of Waste Rocks that Are Generally Stocked in Piles. the Current Research Aims to Investigate the Characterization of Phosphate Mine Waste Rocks (PMWR) Generated in Benguerir, Morocco Mine Site. as a Part of a Wide Project Aiming to Recycle Those Stockpiles, Sensor-Based Ore Sorting Will Be Employed to Separate the Different Lithologies. as a Prior Investigation Before Implementing This Technology, Two Samples of 25 Tons from the Destoning and Screening PMWR Piles Were Sampled and Submitted to Manual Sorting. the Latter Operation Revealed the Presence of Different Lithologies Including Indured Phosphate, Different Types of Siliceous, Carbonate, Phosphorus, and Marly Rock Types. Those Waste Rocks Were Characterized Physically, Chemically, and Mineralogically. their Potential Uses for Recycling or Upcycling Was Investigated and Addressed. About 25% of Indured Phosphate Was Found, Which Can Be First Recovered by Ore Sorting. This Reserve of Residual Phosphate Could Be Recovered using Beneficiation Methods. the Flintstone, Phosphated Flintstone, and Dolomitic Limestone Exhibit Good Physical and Mechanical Properties that Meet the Requirements to Produce Concrete. the Silexite and Siliceous Marls Have a Low Density and Could Be Used as Lightweight Aggregate for Non-Structural Concrete Blocks Production. the Investigation on Tender Marls Corroborates the Literature and their Suitability as Alternative Binders or as Supplementary Cementitious Materials. Those Marls Could Be Used as Well as Lime Binder for Repairing Historical Buildings or as Hydraulic Lime Binder for Road Construction. PMWR Valorization as Road Construction Materials Was Already Proved. However, Studying This Remediation Pathway after the Recovery of Phosphate and Other Lithologies by Ore Sorting is Highly Recommended. the Recycling of Those By-Products Will Decrease the Natural Resources Consumption in the Civil Engineering Field Alongside with Resolving their Environmental Problems

Origin and Salinization Processes of Groundwater in the Semi-Arid Area of Zagora Graben, Southeast Morocco

Located in the southeastern region of Morocco, the Zagora area mainly relies on groundwater as a source of water supply. However, this groundwater is often of concern, due to the limited recharge and unfavorable geological conditions for the development of the aquifer. Despite this, private wells in the Zagora ditch reveal relatively rich water resources. Geochemical and isotopic studies were conducted in the area to understand the origin of the groundwater and its salinity, aiding in informed water management strategies to assist in better planning and regulation of well construction, as well as in mitigating the impacts of high salinity on local water supply and agricultural systems. The results show that the water quality varies, with some wells having conductivity values in excess of 5 mS/cm. Most groundwater samples have high salinity and low pH due to the CO2 dissolved in groundwater. Geochemical analysis indicated two chemical facies: chloride–sulfate calcic/magnesic and bicarbonate calcic/magnesic. The presence of Na+ and Cl− indicated that the origin of these two elements in these waters was the dissolution of halite, with some samples showing an enrichment of Na+ compared to Cl−. This could be attributed to cation exchange. The concentration of Ca2+ and HCO3− suggested that their origin is the dissolution of calcite and the weathering of calcium silicate minerals such as plagioclase. The isotopic analysis showed that the δ18O values ranged from −10.98‰ to −8.54‰, and δ2H values ranged from −75.9‰ to −62.3‰. This indicated that the groundwater originated from the High Atlas with a recharge altitude between 2600 m and 2800 m. The groundwater flows into the graben through fissures and regional fault networks

Copper Mineralization in Adoudounian Cover of the Bou Azzer-El Graara (Anti Atlas, Morocco): Tectono-Stratigraphic Controls

International audienceCopper mineralization in sedimentary cover is well known in association with Pb and/or Zn in Sedex, Kupferschiefer, Mississippi Valley-Type, or Red bed deposits. In spite of great economic potential, the syngenetic versus epigenetic origin of widespread Cu occurrences in the Adoudounian sedimentary cover, in the Moroccan Anti Atlas, remains debated. Significant investigations that would provide critical information for mining exploration are lacking. Whatever their origin, these mineralizations do not correspond to classical sediment-hosted deposits, the ore being exclusively Cu concentrations in dolostone units. This study, based on field and microscopic observations, is focused on Cu mineralization hosted in the Adoudounian cover of the Bou Azzer-El Graara inlier. Two morphologic types of ore bodies exist. The first consists of stratabound lenses and the second type is vein networks along Variscan faults. Both types of mineralization have a stockwork texture and clearly postdate sedimentary fabrics, such as beddings and slumps; this suggests a common epigenetic origin for the both ore types. The proposed interpretation involves the upflow of Variscan fluid-driven interaction between a basement and its sedimentary cover

Gravity study of the Western Bahira Basin and the Gantour Phosphatic Plateau, Central Morocco: interpretation and hydrogeological implications

International audienceThe Western Bahira Basin (WBB), located in Central Morocco, is known for its large reserves of phosphate, which are currently being extracted through open pit mines within the Gantour Phosphatic Plateau (GPP). This mining activity, as well as the increasing agricultural development that this region has been experiencing during the last few decades, has subjected the groundwater in this semi-arid region to intense exploitation through pumping. Consequently, thorough knowledge of the underground water resources is essential for sustained activity. This study uses gravity data to investigate the deep geologic structure of the western Bahira and Gantour plateau area. Its main purpose is to improve the knowledge of this structure that influences the groundwater dynamics. The methodology involves, in addition to the qualitative and quantitative interpretation of the gravity data, the use of various filtering and analysis techniques to highlight the major geological structures. In fact, a qualitative analysis of the residual gravity map shows that the observed anomalies can be explained in terms of the bedrock topography of the study area. Positive anomalies spatially correlate with the outcrops of this bedrock in the Hercynian massifs of Jebilet and Rehamna, as well as with the Douar Rhirat structural high. The negative anomalies, on the other hand, tend to reflect increased thicknesses of sedimentary sequences, such as in the southern part of the WBB. Moreover, the Brikyine granite in the north of the study area is noticeably associated with the highest amplitude negative anomaly. Analysis of the residual gravity data using the total horizontal gradient, upward continuation, and Euler deconvolution techniques provides a quantitative assessment of the geologic structure. These methods help delineate various structures oriented in two main directions: N45E and N105E. Among these structures, several major faults have been identified. They are rooted at a maximum depth in excess of 2800 m. These faults are responsible for the general structure of the study area and the morphology of the basement

The 1750 Ma Magmatic Event of the West African Craton (Anti-Atlas, Morocco)

The Precambrian inliers of the Anti Atlas belt located at the southern part of Morocco contain numerous mafic dyke and sill swarms thought to represent the erosional remnants of Proterozoic Large Igneous Provinces (LIPS). As part of a continuing research campaign to date and characterize these LIPs, four dykes have been dated by the U-Pb TIMS (Thermal Ionization Mass Spectrometry) method on baddeleyite and zircon: ca. 1758 Ma in the Tagragra of Akka inlier, 1741 +/- 10 Ma in the Tafeltast-Kerdous inlier, 1746.8 +/- 3.7 Ma in the Iguerda-Tanst and 1734 +/- 5 Ma in the Zenaga inlier. The age matches (and chemical features akin to continental flood basalts) confirm a widespread intraplate magmatic event at 1750 Ma, herein termed the Tagragra of Akka LIP, that represents an important new magmatic tarcode' line for the West African Craton (WAC). Contemporaneous 1750 Ma LIP magmatism is reported in other crustal blocks including northwestern Laurentia and Siberia; together with the newly defined Tagragra of Akka event of the Anti Atlas region of the WAC this widespread 1750 Ma magmatism is postulated to collectively constitute a single huge LIP associated with a breakup attempt of Nuns (Columbia) shortly after its final assembly at ca. 1.8 Ga. (C) 2013 Elsevier B.V. All rights reserved

Prevalence and risk factors for latent tuberculosis infection among healthcare workers in Morocco.

Increased prevalence of latent tuberculosis infection (LTBI) has been observed among high-risk populations such as healthcare workers (HCWs). The results may depend on the method of LTBI assessment, interferon-gamma release assay (IGRA) and/or tuberculin skin test (TST). Here, we investigated the prevalence and risk factors for LTBI assessed by both IGRAs and TST in HCWs living in Morocco, a country with intermediate tuberculosis (TB) endemicity and high BCG vaccination coverage. HCWs were recruited in two Moroccan hospitals, Rabat and Meknes. All the participants underwent testing for LTBI by both IGRA (QuantiFERON-TB Gold In-Tube, QFT-GIT) and TST. Different combinations of IGRA and TST results defined the LTBI status. Risk factors associated with LTBI were investigated using a mixed-effect logistic regression model. The prevalence of LTBI among 631 HCWs (age range 18-60 years) varied from 40.7% (95%CI 36.9-44.5%) with QFT-GIT to 52% (95%CI 48.2-56.0%) with TST using a 10 mm cut-off. The highest agreement between QFT-GIT and TST (κ = 0.50; 95%CI 0.43-0.56) was observed with the 10 mm cut-off for a positive TST. For a definition of LTBI status using a double positive result for both QFT-GIT and TST, significant associations were found with the following risk factors: being male (OR = 2.21; 95%CI 1.40-3.49; p = 0.0007), belonging to age groups 35-44 years (OR = 2.43; 95%CI 1.45-4.06; p = 0.0007) and even more 45-60 years (OR = 4.81; 95%CI 2.72-8.52; p = 7.10-8), having a family history of TB (OR = 6.62; 95%CI 2.59-16.94; p = 8.10-5), and working at a pulmonology unit (OR = 3.64; 95%CI 1.44-9.23; p = 0.006). Smoking was associated with LTBI status when defined by a positive QFT-GIT result (OR = 1.89; 95%CI 1.12-3.21; p = 0.02). A high prevalence of LTBI was observed among HCWs in two Moroccan hospitals. Male gender, increased age, family history of TB, and working at a pulmonology unit were consistent risk factors associated with LTBI