Lithological and geochemical similarity in the upper triassic sediments (Mulussa and Zor Hauran formations) in the Iraqi Eastern Desert

The lithostratigraphic units of the upper triassic sequence, in their exposure area, in the Western desert of Iraq are investigated in order to establish their lithological character and asses their similarity. 22 lithological sections were described from both Zor Hauran (Rhaetian) and mulussa (Norian Carnian) Formations and 242 samples were analysed for CaO, MgO, Fe2O3, insoluble residue, loss on ignition, Sr and Mn content. A similar regime of sedimentation seems to have prevailed for both lithostratigraphic units. It deduced that they are tidal deposite of hot and arid to semi-arid regions. The geochemical data show a close similarity in the mean concentration of the selected major and trace components in both formations; Such intimate similarity in lithology, geochemical as well as the graditional contact between both units led to the conclusion that they represent one megasedimentary cycle. (author). 23 refs., 5 figs., 1 tabs