Mineralogical and Geochemical Variations Across the Paleocene-Eocene Sinjar Formation, Dokan Area, Northeastern Iraq

Abstract

The Paleocene-Eocene (P-E) Sinjar Formation from Kalka Smaq section, Dokan area, Sulaimaniya, northeastern Iraq has been studied in terms of mineralogy and geochemistry using X-Ray Diffraction (XRD) supported by Scanning Electron Microscopic (SEM) and elemental X-Ray Fluorescence (XRF) geochemical analyses in addition to stable isotopic C and O analysis. The study revealed indications for mineralogical and elemental variation across the P-E transition which may refer to the regionally recognized depositional and paleoclimate changes of the Paleocene Eocene Thermal Maximum (PETM) in the region. The dominance of shallow marine water deposition is interrupted by fresh-water deposition accompanied by increase in temperature suggesting the warming conditions in the Eocene. This result is supported by mineralogical variation in calcite, Mg-calcite and dolomite accompanied with anomalies in δ18O and δ13C data and variation in CaO, MgO, SiO2, TiO2, Fe2O3, and Al2O3 in addition to Co, Ni, Sr and Ba elemental data which in general may suggest the increase in precipitation and low effect of weathering across the P-E transition boundary in the region.