علاقة صخور مكاشف تكاوين فترة السنومانيان البلايستوسين المحيطة بمدينة لبدة الأثرية مع الكتل الصخرية المستخدمة في بناءها و الواقعة شمال غرب ليبيا

Abstract EN

The study of stratigraphy and petrography of carbonate sequences outcrops around the archaeological stony Leptis Magna city, and the rocks of 25 archaeological locations within it, clarified that the city was mainly built from carbonates rocks, brought from the outcrops of three lithostratigraphic units: 1)Al-Khums Fm.

characterized by Borelis Melo Packstone microfacies and Oyster rudistone facies, they sourced from the quarries of Ras Al Hammam and Ghanimah valley; 2) Sidi As Said Fm.(Ayn Tobi Mb.) characterized by the lithology of dolostone and the facies of Orbitolina (Conicorbitolina) conica packsrone microfacies, and Rudist rudistone facies, these might brought from quarries presents in valleys Hajim Al-Haqin, Al-Sayah, Gougaz, and from Al-Khums harbor's outcrops; 3) Gargaresh Calcarenite Fm.

(Karrot Mb.), dominantly used in city walls constructions, sourced from the quarries of Al-Naggazah, Karrout, and from its outcrops near the harbor.

The factor analysis suggest three controlling factors on the dimension stones distribution within the city, these are lithology, time, and topography, The dominant using of Carbonates dimension stones (high porosity) westward, will decreases the risk of thermal variability to its minimum level.

But due to dominant using of igneous and metamorphic dimension stones eastward; porosity certainty decreased, thus thermal variability increase to its maximum level, therefore the risk of deterioration increases eastward.