Source rocks of the ZFTB were deposited under different tectono-sedimentary environments and range in age from Paleozoic to Paleogene. The basal Sarchahan marine shales as the oldest source rock in the ZFTB are characterized with type B organofacies. The Jurassic source rocks of the ZFTB were deposited in intrashelf basins with limited clastic influence due to stable tectonic conditions. These source rocks include the Hanifa/Diyab and Sargelu formations and are characterized with type A organofacies. Important intrashelf basins existed also during the Cretaceous in the ZFTB but received relatively stronger clastic influences due to warm and humid climatic conditions. Major organic-rich intervals including the basal Garau shales (organofacies A/B), the basinal Kazhdumi marls (organofacies B), and the Middle Sarvak source rock (organofacies A) were deposited in these intrashelf basins. The Paleogene Pabdeh Formation is the youngest source rock in the ZFTB and is characterized with type D/E organofacies. During deposition of this source rock, compressional tectonic regime prevailed in the ZFTB due to the active subduction of the Neo-Tethys oceanic crust under the Iranian Plate.