Cadi Ayyad University (Arabic: جامعة القاضي عياض jāmiʿat al-qāḍī ʿayyāḍ, French: Université Cadi Ayyad) is a university in Marrakesh and one of the largest universities in Morocco. One of its associated colleges, the École nationale des sciences appliquées de Marrakech (ENSA Marrakech), was created in 2000 by the Ministry of Higher Education and specializes in engineering and scientific research. Cadi Ayyad University was established in 1978 and operates 13 institutions in the Marrakesh-Safi region of Morocco in four main cities, including Kalaa of Sraghna, Essaouira and Safi in addition to Marrakesh.
This study mobilizes machine learning (ML) and statistical models to predict Co concentrations and classify anomalies in the Bou Azzer ultramafic Complex of the, which hosts significant Co-Ni-Fe mineralization. Based on a dataset comprising geochemical analyses, enriched with ASTER-derived spectral indices (e.g., Serpentinite index, Ferric Index), we applied three regression models: LR as statistical baseline, PLS regression as multivariate statistical method and RF regression as primary ML algorithm in order to predict Co concentrations, while their corresponding version enabled binary anomaly. A 5-fold nested cross-validation framework, with internal feature selection, was used to ensure solid performance and unbiaised performance evaluation, addressing challenges such as small sample size, multicollinearity (e.g., Sc vs. MgO: r = 0.85), and outliers (e.g., 69 ppm Co). PLS Regression outperformed the others models, achieving a MAE of 5-7 ppm, an Area AUC-PR of 0.94, an AUC-ROC of 0.98, and an R2 of 0.60-0.70. Predictive maps align closely with known Co anomalies along the Bou Azzer Fault, highlighting the critical role of serpentinization as a process creating favorable lithological and alteration conditions for Co mineralization. Feature importance analysis confirms Sc (r = 0.883), MgO (0.867), and Ni (0.786) as key drivers of Co distribution. Despite limitations from the small dataset and complex mineralization, this study demonstrates ML's potential to enhance cost-effective, sustainable exploration, offering a scalable framework for targeting critical metals in ultramafic terrains globally.
The transition toward greener construction practices calls for innovative material solutions that reconcile structural performance, thermal comfort, and environmental responsibility. In this context, this study investigates basalt powder (BP), used as a standalone mineral stabilizer for compressed earth blocks (CEBs). Basalt powder and soil were characterized by XRD, SEM, and FTIR, and CEB specimens were prepared with BP contents ranging from 0% to 20%. Results show that BP incorporation improves particle packing, increasing density and reducing porosity up to 15% BP, corresponding to a maximum dry compressive strength of 5.43 MPa (+36.8%), before decreasing at higher dosages due to excessive fine-particle agglomeration. Thermal conductivity decreases continuously with BP content (−15.8% at 20% BP), while thermal inertia improves, as reflected by reduced diffusivity, effusivity, and damping factor. From an environmental standpoint, a comparison with a cement-stabilized reveals an 83% reduction in embodied carbon for the optimal formulation (CEB-BP15), confirming basalt powder as an effective pathway toward more sustainable CEB production.
Abstract The long-term performance of concrete structures depends critically on their durability, governed by transport mechanisms within the matrix. This study aims to determine whether carbonate-rich calcined marl derived from Moroccan phosphate waste can enhance transport-related durability properties of concrete while maintaining long-term mechanical performance at high substitution levels. Concrete mixtures were designed with varying water–binder ratios (0.45 and 0.55) and substitution levels (up to 40% by weight) to evaluate workability, mechanical performance, and durability. Incorporating calcined marl improved electrical resistivity, reduced water absorption, and enhanced sulfate resistance due to its pozzolanic activity and pore refinement effect. Although early-age strength decreased slightly because of dilution, long-term strength development was remarkable, reaching 81% above the control mix at 365 days. The main limitation observed was reduced carbonation resistance, which requires further investigation for practical applications.
