Middle Jurassic plant macrofossils from Mazino, southwestern Tabas, Central-East Iran; Floral gradient analysis

The Middle Jurassic deposits of the Hojedk Formation are widespread in central and central east Iran. In this paper, the Hojedk Formation in Mazino, southwestern Tabas city, central east Iran was studied for palaeobotany and palaeoclimate. This formation contains well preserved plant macrofossils belonging to ۲۹ species assigned to ۱۵ genera of various orders, such as Equisetales, Filicales, Caytoniales, Bennettitales, Cycadales, and Pinales. According to the occurrences of Klukia exilis, Ptilophyllum harrisianum, Nilssonia macrophylla, and Elatides thomasii, an early Middle Jurassic (Aalenian-Bajocian) age is considered for this assemblage. Floral gradient score of this plant macrofossil assemblage is ۵۱.۷۵. Based on this score, it is confirmed that a warm temperate climate for this interval. Moreover, a comparing chart of floral gradient of several localities in the Tabas Block was prepared. It also indicates a nearly uniform palaeoclimate and vegetation occurred in these areas during the early Middle Jurassic.

Keywords:

Middle Jurassic , Plant macrofossils , Palaeoclimate , Mazino , Tabas , Iran