Conglomerate is the main lithology of any succession which has tectonic and paleogeographic importance. The book illustrates many obscurities of the Conglomerates which overlie the Mesozoic radiolarite of north eastern Iraq (Kurdistan region). The present book focused on the Mesozoic thick conglomerate that belong to Zagros mountain belt and cropped out along the Iran-Iraq border. It shows many different lithofacies, stratigraphic position, sedimentary structures and the first time discovering of angular unconformity between the conglomerates and Mesozoic radiolarite which are discussed in detail in the book. The discussions of these properties are used to refuse the previous ideas about the conglomerate and suggest new ones. The new ideas includes changing the age and tectonic setting with suggesting new stratigraphic position.