trace and rare earth element geochemistry of shales in the late

TRACE AND RARE EARTH ELEMENT GEOCHEMISTRY OF SHALES IN THE
LATE TRIASSIC ISPARTAÇAY
FORMATION, ANTALYA NAPPES, WESTERN TAURIDS, TURKEY
Prof. Dr. Mustafa Kuşcu 1
Res. Assist. H. Rıfat Özsoy 1
Prof. Dr. Orhan Özçelik 2
Prof. Dr. Mehmet Altunsoy 2
Res. Assist. Selin Hökerek 2
1
Suleyman Demirel University, Isparta,Turkey
2
Akdeniz University, Antalya, Turkey
ABSTRACT
The Late Triassic shales sequence of Isparta Çay Formation in the Antalya Nappes, Western Taurids, Turkey do not show any trace element enrichment. But trace elements values of shales from the Isparta Çay formation are broadly comparable with those of the average upper continental crust (UC). Among the exception are marked slightly enrichments in Zn, As, Nb, V, Cs, Ga, Ta, Th, Cu ,Pb and Ni. Ba, Co, Hf, Sn, Sr, Mo, Au, Ag, Se, Bi and Sb elements are slightly depleted in Ispart çay Formation shales according to those of UC. Be, U, Zr values are not observed any change. Organic
carbon content of the shales is between 0.16 and 1,36 % but reach 5,24 % in formation. The shales do not show metal/TOC correlation. Organic matter is composed predominantly of woody material, with a minor contribution of planty and amorphous material. Kerogen in the deposits is type III, as indicated by organic petrographic observations and Rock-Eval data. The organic matter is highly oxidized, decomposed and reworked. Compared to the shales of Isparta Çay formation and upper continental crust; shales show a significant increase in HREE and LREE. Our data show slightly negative Ce anomalies (Ce/Ce* as low as 0.96) and positive Eu anomalies (Eu/Eu* as high as 1.99). Ce/Ce* and Eu/Eu* values recorded in the depositional environment indicate low oxygenated and anaerobic (reducing) conditions.
Keywords: Isparta Çay Formation, shales, element geochemistry, TOC