Petrographic and geochemical characterization of sandstones in upper level of ophiolitic melange in Central Pontides

Abstract

Tectonic slices of different origins are observed in eastern of Kargı (Çorum). These slices,
occurred via metamorphic units and lithologies of ophiolitic mélange which are observed
with tectonic contact. The Çalarasın formation is observed at the upper levels of the
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. The
sandstones are poor in terms of REE. 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.