Discrimination Reef and Non-Reef Environments, Using REE Geochemistry

This research aims to distinguish the reef environment from non-reef environment. The Oligocene-Miocene-succussion in western Iraq was selected as a case study, represented by reefal limestone facies of Anah Formation (Late Oligocene) deposited reef-back environments, dolomitic Euphrates (Early Miocene) open sea and gypsiferous marly Fatha (Middle lagoonal content rare earth elements (REEs) (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Ho, Tm, Yb, Lu, Y) appear be much lower than those facies. have low REEs due being transitional phase. investigated ƩREEs PAAS. shows an average higher Global Standard Carbonate Rocks (GSCR), whereas contain lower. Y/Ho, Y/Dy, Er/Nd were used distinctive indicators diagnosis; high value compared PAAS are than1. In contrast, (lagoonal) Y/Dy is 1, but 1. While Y/Ho moderate values close