ABSTRACT Diverse and moderately to poorly preserved palynofloras occur in the lower Middle Jurassic strata of the Hojedk Formation in the Chahrekhneh, southwest of Tabas, east central Iran. The palynofloras comprise 56 species including spores (15 species allocated to seven genera), various types of pollen (30 species designated to 16 genera), dinoflagellate cysts (five representatives of three genera), and one acritarch. The vertical distribution of miospores allows the erection within the Hojedk Formation of one biozone, the Klukisporites variegatus—Callialasporites trilobatus Assemblage zone, based on the first observed occurrence and the last observed occurrence of selected taxa. Moreover, the vertical distribution of dinoflagellate cysts allows the erection within this formation of one biozone, the Nannoceratopsis sp. cf. N. gracilis Interval zone. These biozones are compared with palynozones from approximately coeval strata in Iran and elsewhere. Abundance of ferns and cycadophytes in the parent floras implies that the host strata accumulated under a moist warm climate during the early Middle Jurassic in this locality. Based on various data of ecogroups in Chahrekhneh, it is considered that there were several environments of upland, warmer lowland, wetter lowland, rivers and delta. Furthermore, based on the occurrence of dinoflagellate cysts it can be concluded that Chahrekhneh is located at the south coastal boundary of the Iran Plate, along the Tethys Ocean.

中文翻译：

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伊朗中东部塔巴斯地块西南中侏罗世孢粉学

摘要 在伊朗中东部 Tabas 西南部 Chahrekhneh 的 Hojedk 组中侏罗统下部地层中出现了种类繁多且保存较差的孢粉菌群。孢粉菌群包括孢子（15 种，7 属）、各种花粉（16 属 30 种）、甲藻囊肿（3 属的 5 种代表）和 1 种花粉菌等 56 种。小孢子的垂直分布允许在 Hojedk 组内建立一个生物区，即 Klukisporites variegatus-Callialasporites trilobatus 组合区，基于第一次观察到的事件和最后一次观察到的选定分类群。此外，甲藻囊肿的垂直分布允许在这种生物区的形成中勃起，Nannoceratopsis sp。参见 N。薄薄的间隔区。这些生物带与来自伊朗和其他地方大约同时代的地层的孢粉带进行了比较。亲本植物群中蕨类植物和苏铁类植物的丰富性表明，该地区早在中侏罗世早期，寄主地层在潮湿温暖的气候下积累。根据Chahrekhneh生态群的各种数据，认为存在高地、温暖低地、湿润低地、河流和三角洲几种环境。此外，根据甲藻囊肿的出现，可以得出结论，Chahrekhneh 位于伊朗板块的南部沿海边界，沿特提斯洋。亲本植物群中蕨类植物和苏铁类植物的丰富性表明，该地区早在中侏罗世早期，寄主地层在潮湿温暖的气候下积累。根据Chahrekhneh生态群的各种数据，认为存在高地、温暖低地、湿润低地、河流和三角洲几种环境。此外，根据甲藻囊肿的出现，可以得出结论，Chahrekhneh 位于伊朗板块的南部沿海边界，沿特提斯洋。亲本植物群中蕨类植物和苏铁类植物的丰富性表明，该地区早在中侏罗世早期，寄主地层在潮湿温暖的气候下积累。根据Chahrekhneh生态群的各种数据，认为存在高地、温暖低地、湿润低地、河流和三角洲几种环境。此外，根据甲藻囊肿的出现，可以得出结论，Chahrekhneh 位于伊朗板块的南部沿海边界，沿特提斯洋。