TY - JOUR

T1 - Source rock potential and depositional environment of the lower oligocene İhsaniye formation in NW Turkey (Thrace, Karaburun)

AU - Tulan, Emilia

AU - Sachsenhofer, Reinhard F.

AU - Tari, Gabor

AU - Flecker, Rachel

AU - Fairbank, Vanessa

AU - Pupp, Magdalena

AU - Ickert, Ryan B.

PY - 2020/1/2

Y1 - 2020/1/2

N2 - The Lower Oligocene succession of the İhsaniye Formation, exposed at Karaburun on the Turkish (Thrace) coast of the BlackSea, provides insights into potential hydrocarbon source rock extent in the southwestern part of the Black Sea Basin. Presently, nodetailed study of the İhsaniye Formation exists with regards to organic matter content and type. We analyzed 78 fine-grained samplesfrom a c. 70-m-thick section near Karaburun. Relatively high total organic carbon (TOC) contents (average 1.45 wt.%) are present inthe lower part of the İhsaniye Formation; the hydrogen index values reach a maximum of 252 mg HC/g TOC, indicating the presence oftype III–II kerogen, and the organic matter is thermally immature (Tmax 418 °C). The presence of foraminifera and TOC/S ratios below2.8 confirm a fully marine environment. Elevated TOC contents and very low pristane/phytane ratios indicate an oxygen-depletedenvironment during deposition of the lower part of the İhsaniye Formation. The quartz/clay minerals ratio suggests a deepening trend inthe lower part of the succession and a shallowing trend in the upper part. Peculiarly, the low salinity “Solenovian Event” (in nannofossilzone NP23) is not developed although Sr isotope ratios indicate that the basin was only connected to the Mediterranean for shortperiods during deposition of the İhsaniye Formation.

AB - The Lower Oligocene succession of the İhsaniye Formation, exposed at Karaburun on the Turkish (Thrace) coast of the BlackSea, provides insights into potential hydrocarbon source rock extent in the southwestern part of the Black Sea Basin. Presently, nodetailed study of the İhsaniye Formation exists with regards to organic matter content and type. We analyzed 78 fine-grained samplesfrom a c. 70-m-thick section near Karaburun. Relatively high total organic carbon (TOC) contents (average 1.45 wt.%) are present inthe lower part of the İhsaniye Formation; the hydrogen index values reach a maximum of 252 mg HC/g TOC, indicating the presence oftype III–II kerogen, and the organic matter is thermally immature (Tmax 418 °C). The presence of foraminifera and TOC/S ratios below2.8 confirm a fully marine environment. Elevated TOC contents and very low pristane/phytane ratios indicate an oxygen-depletedenvironment during deposition of the lower part of the İhsaniye Formation. The quartz/clay minerals ratio suggests a deepening trend inthe lower part of the succession and a shallowing trend in the upper part. Peculiarly, the low salinity “Solenovian Event” (in nannofossilzone NP23) is not developed although Sr isotope ratios indicate that the basin was only connected to the Mediterranean for shortperiods during deposition of the İhsaniye Formation.

KW - Hydrocarbon source rock

KW - Lower Oligocene

KW - Paratethys

KW - Strontium isotopes

KW - West Black Sea Basin

UR - https://journals.tubitak.gov.tr/cgi/viewcontent.cgi?article=1121&context=earth

UR - http://www.scopus.com/inward/record.url?scp=85078554351&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:85078554351

VL - 29.2020

SP - 64

EP - 84

JO - Turkish Journal of Earth Sciences

JF - Turkish Journal of Earth Sciences

SN - 1300-0985

IS - 1

ER -