Assessment of the magmatic sources and thermal transformations of the Abu Sheiba Formation igneous dividing, northwest Libya”

Abstract:

 The Abu Shaybah reservoir area in northwestern Libya lacks integrated studies examining igneous dykes and their petrological, economic, and environmental impacts, despite promising mineral potential. Four rock samples representing the igneous dyke (DI, DTI) and surrounding rocks (AS1, AS2) were collected from the Abu Shaybah Formation. X-ray fluorescence spectrometry (XRF) was used for major and trace element analysis, applying rigorous quality control protocols and instrument calibration. Results were statistically analyzed using SPSS and the TAS classification diagram. The dyke is classified as basalt (SiO₂: 42.26-43.13%, total alkalis: 1.64-1.84%), with clear magmatic differentiation concentrating titanium (4.15%) at the dyke margin, exceeding the economic cut-off grade (3%). Iron showed sub-economic concentration (12.95%). Intense thermal metamorphism was documented in the contact sample (AS1), manifested by 93.6% silica loss and 143.3% calcium oxide increase. Environmentally, chromium concentration (0.07%) exceeded permissible limits by 700%, classifying the area as medium environmental risk.  Exploration should focus on the dyke body for titanium and iron ores, implement mitigation measures for environmental risks (groundwater monitoring, tailings treatment), and conduct future petrographic studies to confirm rock classification.

Keywords: Igneous dyke, basalt, Abu Shaybah Formation, XRF spectrometry, economic assessment, environmental risks, Libya.