Determination of Palynofades to Assess Depositional Environments and Hydrocarbons Potential ,Lower Cretaceolls,Zubair Fomation South lraq

Fourteen selected rock samples from lower and middle parts of Zubatu Formation in Zubair lW (h-109) and Zabu 43 (h43) boreholes of Zubair field at southern kaq. Standard palynological processing techniques were used to extract the acid resistant organic matter. Assemblages of miospores and dinoflagellate cysts encountered in core samples from two boreholes indicate Barremian to Aptian agerange for the lower and middle parts of Zubur Formation. According to the statistical analysis of organic matter in the studied sections included three types of palynofacies : @F-l) Marginal dysoxic- anoxic basin facies is characterized by diluted amorphous organic matter of moderate preservation, high phytoclasts and the kerogen in this facies is type Itr gas prone.( PF-2) Oxic shelf facies is characterized by phytoclasts predominantly and low preservation amorphous organic matter, the kerogen in this facies is represented by two types trI-IV gas prone.(PF-3) Shelf to basin transition facies (suboxic - dysoxic) is characterized by increased subsidence and water depth and the kerogen in this facies is type tr-Itr oil - gas prone. From the facies analysis it appeared that the lower and middle strata of the formation had deposited in environments extending from deltaic environment to neritic environment near the shore.