نوع مقاله : مقاله پژوهشی
نویسندگان
Department of Earth Sciences, Faculty of Sciences of Sfax, University of Sfax, Sfax, Tunisia
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The sequence stratigraphy of mixed sequences with evaporitic intercalations is already reported in several works in the world. The present work aims to study the sequence stratigraphy of the mixed sequences of the Zebbag Formation (Albian-Cenomanian) in Central Tunisia.
This study is based on the surveying of a 140 m-thick geological section of the Zebbag Formation with a tight sampling of the carbonate levels, completed by the microscopic observation of thin sections and the analysis of the chemical composition of the carbonates.
According to the vertical changes of the depositional facies notably the carbonate facies on one hand, and the vertical variation of the chemical composition of the carbonate levels on another hand, the Zebbag Formation can be subdivised into 22 mixed sequences that developed in a marginal setting at the southern tethytian border. The sequences were controlled by the fluctuation of sea-level and recorded the alternating marine regression and transgression and respectively the resulting continental and marine influences. All the sequences show at the base an evaporite succession representing the lowstand system tract, whereas the transgressive and the highstand system tracts are materialized by different deposits according to the depostional environment. Indeed, in the inner position of the margin these system tracts are represented by bedded limestone, whereas in the outer position by marls. In the middle position on the margin, the transgressive and highstand system tract are recorded by interbedded marls and limestones
کلیدواژهها [English]
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