The Mineral Composition of Some Soil Formed on Different Source Materials and Its Relationship to Their Properties and Degree of Development

This study was conducted during 2023 on soil profiles in Lattakia Governorate (Syria), composed of different parent materials, namely serpentine, gabbro, peridotite (belonging to the ophiolitic complex), and marl (belonging to sedimentary formations). The aim was to determine their mineral composition and study the effect of mineral composition on some soil properties, alongside the degree of weathering of soil profiles. The mineral composition of the soil profiles varied and was primarily related to the differences in parent materials. Primary minerals dominated the mineral composition of the horizons of profiles formed on ferromagnesian rocks, while the mineral composition varied in the horizons of profiles formed on marl, depending on the impurities accompanying the limestone rock, with a great majority of calcite minerals. The type of mineral composition affected the morphological characteristics of the soil, such as color change. Most profiles of the ophiolitic rocks took on a red color because they contained hematite, while the light color prevailed in the profiles formed from marl due to the dominance of calcite minerals in their composition. The presence of montmorillonite caused some cracks in the profile containing it. Soils formed from ferromagnesian rocks were characterized by a low Ca/Mg ratio compared to other soils, due to the richness of their mineral composition with primary minerals containing magnesium, leading to the dominance of exchangeable magnesium, while the calcium cation was dominant in the soils formed on parent material rich in calcium carbonate.