Palynostratigrapgy of Hojedk Formation in the Mazino, Southwest Tabas; palaeoenvironment analysis

Diverse and moderately preserved palynofloras occur in the lower Middle Jurassic sediments of the Hojedk Formation in the Mazino, southwestern of Tabas, east central Iran. This palynofloras comprise thirty-six species including spores (fourteen species allocated to eleven genera), and various types of pollen (twenty-two species designated to ten genera). Vertical distribution of miospores allows erection within the Hojedk Formation of one biozone–Klukisporites variegatus Taxon Range zone– based on the first observed occurrence (FOO) and the last observed occurrence (LOO) of selected taxa. Moreover, this biozone compared with palynozones from ±coeval strata in Iran and elsewhere. Abundance of ferns and cycadophytes in parent floras implies that the host strata accumulated under a moist warm climate during the early Middle Jurassic in this locality. In addition, Based on various data of sporomorph ecogroups (SEGs) in Mazino, it should consider that there were several environments of upland, lowland, river, and tidally influenced delta. Besides, hygrophytes and megathermic eco-plants distribued in the Mazino area during this time interval.