This study aims to investigate the stabilization of representative samples of expansive soil in the Al-Azraq area. This is achieved by mixing soil with different proportions of four types of stabilizers: lime, phosphatic clay, cement kiln dust (CKD), and sandstone. The index properties of the base soil have been investigated through various tests. The chemical and mineralogical compositions of materials have been examined. Compaction, California bearing ratio, and unconfined compression tests are used to assess the engineering properties of the stabilized soil. The results revealed that with 5% lime, 10% phosphatic clay, 7.5% CKD, and 10% sandstone, the plasticity index reduced from 60% to 17.2%, 18.47%, 17.52%, and 22.70%, respectively. The maximum dry density increased by adding 5% lime from 1.19 mg/cm3 to 1.58 mg/cm3. The optimum moisture content decreased from 40.1% to 25.1% with the addition of 5% lime. The California bearing ratio increased from 9% to 17.5% with the addition of 7.5% CKD. The unconfined compression strength improved significantly with the addition of all stabilizers due to chemical reactions that resulted in the production of binding compounds. The maximum compressive strengths were after 21 days of adding 5% lime and 7.5% CKD (1800 and 1720 Mpa, respectively). According to the results, the addition of 5% lime and 7.5% CKD is responsible for forming new product-binding materials that improve mechanical strength via the pozzolanic reaction. Reusing by-product materials such as CKD and phosphatic clay as non-traditional soil stabilizers could reduce the amount of these materials destined as waste.

This study reports the discovery of a newly identified phosphorite deposit in the Al-Tafeh area of northern Jordan. Geological fieldwork investigated three outcrops and one comparison site in the Russifa area. Geochemical analyses reveal a high P₂O₅ content (average 24.32 wt.%), strongly correlating with CaO. There are also significant levels of trace elements, including uranium (0.045 mg/g), cadmium (0.025 mg/g), and zinc (0.099 mg/g). Mineralogical investigation reveals that francolite is the main phosphate mineral. Calcite and quartz are also present. Petrographic analysis reveals the presence of pellets, skeletal fragments, coated grains, and indicators of storm deposits, bioturbation, and fossil-rich layers. These findings indicate that the Al-Tafeh area in northern Jordan is an important yet under-explored area for phosphorite, suggesting that this discovery could have significant economic value.

Upper Cretaceous carbonate rocks in Jordan are the main resources for construction and paint-related industrial applications. This study evaluates the elemental composition, mineralogy, and petrography of two main geological formations from two localities in northern Jordan (Hallabat, Turonian age, and Ajlun, Santonian–Campanian age) to shed light on their composition, depositional environments, and potential industrial end uses. The elemental composition of the Hallabat Wadi Sir Limestone (WSL) Formation indicates notable variability between the middle and upper parts of the WSL carbonates in the area, with higher CaO content in the middle part (mean 55 wt.%) and higher silica content observed in the upper part (mean 2 wt.%) compared with the middle part (mean 0.9 wt.%). Meanwhile, analysis of the elemental composition of the Ajlun Amman Silicified Limestone (ASL) Formation indicates that the CaO content is relatively higher in the upper part (mean 56 wt.%). In addition, the lower part is more influenced by detrital input when compared with the upper part of the studied section, in contrast to the Hallabat WSL Formation. Petrographic analysis demonstrates that the WSL and ASL samples are predominantly micritic limestone. The XRD results for the Hallabat WSL and Ajlun ASL show that the mineralogical composition is dominated by calcite (CaCO₃). Statistical and PCA analyses also confirm these variabilities between the two sites, indicating that all samples from both sites were deposited under variable hydrodynamic and environmental conditions that affected their physical and chemical composition. The results show that all studied samples are in the range of pure limestone and can be used for specific industrial applications in addition to their current uses, including those in the pottery and porcelain ware, soda ash and caustic soda, steel industry, sugar, and textile production industries, thus contributing to the economic resources in Jordan.