Cenomanian–turonian platform evolution and records of OAE 2 on the drowned northern arabian carbonate platform (se Turkey): Integration of biostratigraphy, sequence stratigraphy, sedimentology, and stable isotopes

Mülayim, Oğuz
The evolution of the Cenomanian–Turonian (C–T) carbonate platform (northern Arabian Platform) in southeastern Turkey has been embraced with special emphasis on the sedimentology, biostratigraphy, lithostratigraphy, sequence stratigraphy, and stable–isotope geochemistry. The interplay of different sedimentologic features on the ramp type platform is deciphered on the basis of field and subsurface observations, detailed stratigraphic sections, macrofacies, and microfacies analyses, stable δ 13C and δ 18O isotope ratios, and fossil distribution patterns. A new multibiostratigraphic framework is based on planktonic foraminifera, rudists, and calcareous nannofossils supplemented by benthic foraminifera, pithonellids, and roveacrinids. The sequence stratigraphic framework of the Cenomanian–Turonian boundary was constructed and recorded in the transition of the transgressive systems tract (TST) to highstand systems tract (HST), coinciding with a maximum flooding surface. There are three sedimentary sequences that are separated by the C–T sequence boundary. The studied sections indicate a change from TST to HST in shallow to deeper marine deposits. Furthermore, comparisons between the ramp type platform successions and sequence patterns of SE Turkey and those from neighbouring areas allow us to differentiate local, regional, and global controlling factors of platform evolution within the study area. The microfacies analyses, multibiostratigraphic datings, and paleoenvironmental interpretations suggest that the platform was drowned near the Cenomanian–Turonian Boundary Event (CTBE) into shallow–water environments.as a result of changing environmental conditions. A filament event is also recorded around the boundary. On a global scale, the filament event beds illustrate sea–level rise related to eustacy and/or climatic change. The abundance of filaments close to the C–T boundary is a biological marker of high organic productivity resulting in a climatic change to warmer conditions. The prevailing higher sea–level conditions were then favourable to the accumulation and preservation of organic–rich facies, characteristic of the Oceanic Anoxic Event 2 (OAE 2). Regional/local subsidence and a coeval sea–level rise during the late Cenomanian to early Turonian interval were the cause of the drowning of the platform, including regional anoxia at the northern Arabian Platform linked to the OAE 2. Carbon–isotope stratigraphy of these successions in shallow–water environments revealed a positive shift δ13C (V–PDB) values that reached between 0.21‰ and 2.15‰ and represent the CTB interval excursion pointing to the presence of OAE 2. These results spotlight the potential use of carbon isotopes as a dating and high–resolution correlative tool in shallow–water carbonate rocks and help to elucidate the timing of oceanographic events affected the area that we studied. In particular, it is suggested that the highest rate of a relative, possibly tectono–eustatic sea–level rise took place during the latest Cenomanian, that was followed by the global oceanic anoxic event (OAE 2) around the CTB interval, and that peak transgression or maximum flooding was achieved during the early Turonian in this region. The time difference between the end of the OAE and the establishment of a shallow platform is attributed to the Turonian sea–level rise and tectonic effect.


Upper Jurassic-Lower Cretaceous depositional environments and evolution of the Bilecik (Sakarya Zone) and Tauride carbonate platforms, Turkey
Yılmaz, İsmail Ömer; Altıner, Demir (2016-05-01)
Three Late Jurassic-Early Cretaceous carbonate platform stratigraphic sections have been studied in central western Turkey (Bilecik carbonate platform at Bilecik and Saricakaya) and in the Taurides in southern Turkey (Tauride carbonate platform at Beysehir) by using sedimentological and cyclostratigraphical methods. One section was analyzed by detailed magnetic susceptibility measurements. Peritidal carbonates on both platforms display cyclic patterns throughout the sections and do not contain any silicicla...
Cenomanian-Turonian drowning of the Arabian Carbonate Platform, the Inisdere section, Adiyaman, SE Turkey
Mulayim, O.; Yilmaz, O. I.; Sari, B.; Tasli, K.; Wagreich, M. (Geological Society of London, 2020-01-01)
The Cenomanian-Turonian carbonate ramp in the Adiyaman Region of SE Turkey (Northern Arabian Platform) records an abrupt shift from benthic carbonate deposits to pelagic deposits near the Cenomanian-Turonian boundary event (CTBE) in the Inisdere stratigraphic section and surrounding borehole sections. A positive delta C-13 excursion of up to 2.15% is recorded in carbonate and organic carbon deposited around the CTBE and provides evidence of a direct link between the CTBE and oceanic anoxic events and the de...
Seismic stratigraphy of Late Quaternary deposits on the continental shelf of Antalya Bay, Northeastern Mediterranean
Tezcan, Devrim (2006-09-01)
The Late Quaternary sedimentation and structural features of the continental shelf of Antalya Bay (SW Turkey) have been investigated using a single channel high-resolution shallow profiling system. Two seismic units denoted as unit 1 and unit 2 bounded by two major unconformities (R-1 and R-2) have been identified. R-1 and R-2 are type-1 sequence boundaries that formed under sub-aerial conditions during the Late Quaternary sea level lowstands. An acoustic basement (AB) is recognized in the study region; it ...
Upper Cenomanian-Lower Campanian Derdere and Karababa formations in the Cemberlitas oil field, southeastern Turkey: their microfacies analyses, depositional environments, and sequence stratigraphy
Mülayim, Oğuz; Mancini, Ernest; Çemen, İbrahim; Yılmaz, İsmail Ömer (2016-01-01)
The frontal belt of the southeastern Anatolia fold-thrust belt in Turkey contains several small to mid-size oilfields, producing from carbonate reservoirs of the Cretaceous Mardin group. Many of these fields are found along narrow, asymmetrical anticlinal structures, associated with the formation of the fold-thrust belt. The emberlitas oil field in Adiyaman, southeastern Turkey, is one of the most important oilfields in the region. It produces from the Upper Cretaceous Derdere and Karababa formations of the...
Cyclostratigraphy and sequence boundaries of inner platform mixed carbonate-siliciclastic successions (Barremian-Aptian) (Zonguldak, NW Turkey)
Yılmaz, İsmail Ömer; Altıner, Demir (2007-04-20)
Barremian-Aptian shallow marine mixed carbonate-siliciclastic successions of the Zonguldak area (NW Turkey) have been studied in detail along three measured stratigraphic sections. Field and laboratory analysis of microfacies and sedimentary structures have demonstrated that sections are composed of meter-scale shall owing-upward cycles. Cyclicity of shallow water mixed carbonate-siliciclastic successions are generally observed in the form of alternating sandstone/siltstone or sandy limestone and limestone....
Citation Formats
O. Mülayim, “Cenomanian–turonian platform evolution and records of OAE 2 on the drowned northern arabian carbonate platform (se Turkey): Integration of biostratigraphy, sequence stratigraphy, sedimentology, and stable isotopes,” Ph.D. - Doctoral Program, Middle East Technical University, 2020.