Türkiye Jeoloji Bülteni

Depositional Environments and Hydrocarbon Source Rock Assessments of the Upper Devonian-Lower Triassic Sequence of Aladağ Unit: Central Taurus, Turkey

Abstract: The depositional environments and source rock assessment of the Aladağ Unit formations in the Central Taurus region have beenstudied on surface samples collected from the five different sections which extend in the Sarıveliler and Aydıncık regions. In bothregions, the formations of the Aladağ Unit were deposited on the tidal-flats, restricted shelf areas and reefal environments whichbelong to a carbonate platform through Upper Devonian and Cretaceous. Geochemical data (TOC content, Tmax and HI values) andorganic petrography (Spore-Pollen Colour Index) values obtained from Rock-Eval pyrolysis and transmitted light microscopy. In theAydıncık region, although the Dikenlidere Formation (Carboniferous) has enough TOC content (over 0.5 %), Akdere (UpperDevonian) and Cevizli (Permian) formations have no source-rock potential. Only Cevizlt Formation in the Sariveliler region has somesource-rock levels displaying TOC values over 0.5 %. HI, Tmax and SCI values indicate that all source rock samples of the Aladağunit formations are over mature and their primarily organic matter type is Type III kerogen (coaly). However, depositional environment conditions providing the abundant algal productivitiy imply mainly the presence of the Type I (algal) organic matter