ÇAĞRILI KONUŞMALAR / KEYNOTES Invited Speeches ... - TPJD

Redox Conditions of Depositional Environment of The Shale and Marl Type
Organic Matter-Rich Rocks (Kürnüç–Göynük/Bolu)
Hilal Engin, Ali Sarı, Şükrü Koç
Ankara University, Faculty of Engineering, Department of Geological Engineering, Ankara
Kabalar Member of Kızılçay formation in the northwestern Göynük is rich in organic matter-rich
rocks of marl and shale. Organic matter-rich rocks are enriched by major, trace and rare earth
elements. The results of element analysis of organic matter rich rocks in study area showed that
rocks are enriched by Ni, Co, Ca, Mn, Cr, Th, Pb, Zr, Sc, Ta, Cs, V, W, As, Sr, Ag, Se, Hf, Cu, Y, Si,
Mg, Na, Ti. Some information about redox conditions of depositional environment of organicrich
rocks are obtained using redox sensitive element ratios such as V/(V+Ni), V/Cr, Ni/Co, U/
Th and V/Sc. These ratios V/(V+Ni) came out to be between 0,44-0,67, indicating suboxic-anoxic
conditions; V/Cr ratios are between 0,85-2,15 which indicates oxic conditions; Ni/Co values are
between 4,08-11,76, which indicates oxic-suboxic conditions; U/Th values are between 0,46-
6,00, indicating suboxic-anoxic conditions; V/Sc values are between 5,53-24,50, indicating
oxic-suboxic condition. According to these values, Kürnüç vicinity organic matter-rich rocks are
generally deposited in oxic to anoxic redox conditions.
Keywords: Redox conditions, depositional environment, organic carbon, trace element, Kürnüç
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