WITHDRAWN: Seismic sequence stratigraphy and depositional conceptual modelling of the Beriasian- Early Valanginian lower Fahliyan Formation in the northwestern Persian Gulf, SW Iran

Abstract

This study presents a seismic stratigraphic-based sedimentary conceptual modelling through integration of well data, seismic data, and literature in order to identify the architecture of the Berriasian- Early Valanginian lower Fahliyan Formation in the northwestern Persian Gulf. The applied methodology is configured by interpreting seismic sections in terms of sequence stratigraphy and adapting them using well data facies associations and fossil assemblages. The time framework of these sediments is identified by their faunal/flora assemblage and extrapolated by seismic data because of their extensive coverage. Three third order depositional sequences (DS-I, DS-II, and DS-III) were distinguished based on the facies changes, depositional geometries, and fossil assemblages. Regional and local tectonic activities and global sea-level changes controlled the sedimentation of the depositional sequences. The local tectonic activities were of higher importance as they strongly affected the thickness and facies type of the studied interval. The depositional sequences of the lower Fahliyan Formation deposited in the inner to outer settings of a carbonate shelf. It was concluded that DS-I and DS-II over platform (Surmeh platform), consisting of progradational parasequences, deposited during the high-stand phase in shoal settings that due to primary texture and subsequent diagenetic imprints yield the best reservoir quality. The relationship of the parasequences with good reservoir quality determined on seismic sections and the prepared regional correlation panel over the study area. Furthermore, geodynamic evolution of the area was constructed and modelled for major stratal surfaces (Sequence boundaries and maximum flooding surfaces). According to the generated geodynamic models, the distal setting (Garau Basin) migrated-back gradually northward during the Beriasian-Early Valanginian as a way that it was completely replaced by a homoclinal ramp by the end of the deposition of DS-III. Subsequently, Surmeh platform relief was also flattend and recognized as the end of the first phase of the basin activity.