Rare earth element (REE) geochemistry and genesis of oil shales around Daǧhacilar village, Göynük-Bolu, Turkey


Çimen O., Koç Ş., SARI A.

Oil Shale, cilt.30, sa.3, ss.419-440, 2013 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 30 Sayı: 3
  • Basım Tarihi: 2013
  • Doi Numarası: 10.3176/oil.2013.3.04
  • Dergi Adı: Oil Shale
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.419-440
  • Anahtar Kelimeler: Daǧhacilar, Major elements, Oil shale, Organic carbon, Rare earth elements
  • Ankara Üniversitesi Adresli: Evet

Özet

The study area is located in the south of Daǧhaci{dotless}lar village of Göynük town in Bolu Province, Turkey. This study is a pioneering work in Turkey on the genesis and environmental characteristics of oil shales and other shallow marine-type sedimentary rocks regarding their major and rare earth element contents. The abundances of SiO2, Al2O3, TiO2, K2O and Fe2O3 decrease in the following order: claystone > oil shale > marl. CaO and MgO abundances are ranked in the decreasing order as follows: marl > oil shale > claystone. These results reveal the presence of two different genetic groups - detrital and marine. The same groups were also established in the correlation studies of elements. TOT/C and TOC contents of rocks observe the following order: oil shale > marl > claystone, and as a result of variations in redox conditions they also vary in a wide range. Total carbon and total organic carbon are positively correlated with the group representing clays and negatively correlated with CaO, MgO and MnO. That is why TOT/C and TOC are associated with clays. The positive correlations between some major oxides (e.g. SiO2, Al2O3, Fe2O3, TiO2 and K2O) and REE might indicate that clays and iron oxy-hydroxyls play an important role in transportation and deposition processes. The only slight negative Ce and positive Eu anomalies and Ce/Ce* and Eu/Eu* values recorded in the depositional environment indicate low oxygenated and anaerobic (reducing) conditions. © 2013 Estonian Academy Publishers.