Provenance, petrographic and geochemical signatures of sandstones in Çalarasın Formation: A unit of ophiolitic melange in eastern of Kargı District


Yalçın C., Hanilçi N., Kumral M., Kaya M.

Engineering Applications, cilt.1, sa.2, ss.145-156, 2022 (Hakemli Dergi)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 1 Sayı: 2
  • Basım Tarihi: 2022
  • Dergi Adı: Engineering Applications
  • Sayfa Sayıları: ss.145-156
  • İstanbul Üniversitesi-Cerrahpaşa Adresli: Evet

Özet

Tectonic slices of different origins are observed in the eastern of Kargı (Çorum) district. These slices'  metamorphic  units  and  lithologies  of  ophiolitic  melange  are  observed  with  tectonic contact. The Çalarasın formation is observed at the upper levels ofthe  ophiolitic  mélange, which extends to the east of Kargı (Çorum) in the Central Pontides. The formation is composed of   thin-bedded   siltstone   intercalated   sandstone-shale   and   mudstone   alternations.   The sandstones of the formation include quartz, plagioclase, calcite, biotite, chlorite, and volcanic rock  particles.  The  sandstones  were  analyzed  for  geochemical  properties  and  provenance traces,  respectively.  According  to  these  analyzes,  SiO2%  is  found  between  26.46-71.78%, Al2O3%   5.22-10.86,   Fe2O3%   2.89-7.11   and   CaO%   6.13-36.02   respectively.   When   trace elements are evaluated, Sc content ranges from 76.13-201.03 ppm, and Y content ranges from 9.54-55.11 ppm. Sandstones are rich in large ion lithophile elements (LIL; Ba, Th, U) and poor in high-field strength elements (HFS; Nb, Ti, Zr). Positive anomalies in terms of Pb and Y and negative ones in terms of Eu and P are observed in rocks. The sandstones are poor in terms of REE. The amount of HREE is substantially richer than the amount of LREE. Sandstones were normalized  according  to  PAAS,  and  a  distribution  inversely  proportional  to  the  primitive values  emerged.  Ce/Ce*  anomaly  displays  that  the  same  oxygen  environment  has  existed  in the environment for a long time, but this situation has changed in the transition zone. Major oxide values suggest that the environment is arid and semi-arid media. It was determined that the sandstones were fed from the intermediate and mafic magmatic sources and tectonically represented the active continental margin and the island arc area.