Mineral Composition of Coastal Landforms in Wadi Al-Suwani at Al-Bardia Region, East of Tobruk City, Libya

Abstract

This study investigates the mineralogical composition of coastal geomorphological units, including sabkhas, rock cliffs, and beach sands, along the Wadi Al-Suwani shoreline near Burdi village in  east of Libya. The research aimed to characterize these landforms, focusing on their geochemical and mineralogical properties, to better understand the processes shaping this unique coastal landscape. A total of fifteen samples were collected during field trips in August and September 2022, spanning various geomorphological units such as sabkhas, rock cliffs, and beaches. X-ray diffraction (XRD) analysis revealed that intertidal sabkha sediments predominantly contain terrigenous minerals like quartz (40.7%-69.7%), microcline (34.6%-39.0%), and albite (7.7%-13.7%), with minor occurrences of carbonate minerals such as calcite (9.5%-30.6%) and dolomite (1.3%-5.4%). The supratidal sabkha sediments were primarily composed of quartz (45.7%-69.7%) and lesser amounts of microcline and calcite, while halite was notably absent. Beach sands exhibited a mineralogical profile dominated by quartz (41.2%-78.2%) and calcite (19.1%-50.4%), with traces of dolomite and hematite. In contrast, the rock cliffs of the Al-Abraq, Al-Faidiyah, and Al-Jaghbub Formations were overwhelmingly composed of calcite (83.4%-97.9%), indicative of their shallow marine origin, with minor quartz and halite content. The findings underscore the complexity of depositional processes in the region, shaped by a combination of terrigenous input, marine biogenic activity, and evaporative conditions. This research provides valuable insights into the coastal geomorphology of the Al-Bardia region, with broader implications for understanding similar coastal environments globally.