Akademik Veri Yönetim Sistemi
Mediterranean Geoscience Reviews, cilt.6, sa.4, ss.543-569, 2024 (Scopus)
The İskenderun-Arsuz sub-basin (IA) in southern Türkiye underwent Zanclean transgression following the deposition of the Messinian Upper Evaporite (gypsum, sandstone). The evaporite-bearing sandstones were formed during episodes of freshening saline water, presumably under brackish conditions; however, Lago-Mare facies characterized by diagnostic Paratethyan biozones were absent. The transgressive Zanclean units were deposited along both non-tectonic and tectonic basin margins. The non-tectonic margins exhibit a tripartite character, with lateral and vertical transitions from estuarine-lagoon to barrier/beach deposited between land and open sea intervals. These environmental settings provide an ideal depositional model for Zanclean basins in the easternmost Mediterranean, comparable to recent counterparts that evolved from normal regressive (progradational) to transgressive (retreating) barrier-lagoon systems. These tidally influenced estuarine environments range from marine-brackish to freshwater, characterized by sandy dunes, tidal flats, and fluvial incisions, and locally featuring shell pavements and herringbone cross-beds within estuarine mudstone, including dolomite-palygorskite levels. These transitions indicate that stable marine conditions were not established during the initial phase of the Zanclean transgression. Compared with similar Mediterranean basins, environmental stability, and normal marine conditions occurred approximately 20 kyrs later. The tectonic basin margin, controlled by fault activity, is evidenced by fan delta/debris flow deposits associated with sandy-gravelly coastal regions influenced by wave and storm activity and subject to river floods. Additionally, the dolomite-palygorskite pair precipitated in estuarine-lagoon mudstone is first recorded in this study among Mediterranean post-evaporitic Zanclean basins. Water and gas escape structures were identified in the IA sub-basin, marking the first report of such features for the post-evaporite basins in the easternmost Mediterranean. These structures were induced by regional tectonic activity, presumably associated with strike-slip faulting that produced large-scale tectonic flower structures in the lagoonal mudstones. Gas escapes and hydrocarbon injections entered the siliciclastic beach sandstones, accompanied by hydrocarbon-filled microfractures and sandstone-filled normal faults. These non-tectonic faults exhibit limited throw, with centimeter to decimeter-wide apertures, poorly developed fault zones, and either fully or partially sand-filled.