Abstract Palynological study of the Upper Triassic Bidestan and Howz-e-Sheikh members of the Nayband Formation of the Tabas Block, Central Iran, revealed relatively diverse and well-preserved assemblages of palynoflora dominated by dinoflagellate cysts and miospores. The two well-known interval dinoflagellate cysts zones of Hebecysta balmei Interval Zone and Rhaetogonyaulax rhaetica Interval Zone were differentiated based on the index dinoflagellate cysts recorded and confirmed the middle Norian-Rhaetian age for the members. The palynological content of these dinoflagellate cyst zones are quite comparable to the Upper Triassic zones of Australia. Biogeographically, the recorded palynomorphs are a mixture of both Eurasian and Gondwanan elements but the middle Norian to earliest Rhaetian elements are more closely related to Gondwanic flora. The co-occurrence of marine and terrestrial elements suggests a shallow marine environment for the members studied.

中文翻译：

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伊朗中部 Tabas 地块 Nayband 组（上三叠统）的孢粉学

摘要 对伊朗中部 Tabas 地块 Nayband 组的上三叠统 Bidestan 和 Howz-e-Sheikh 成员的孢粉学研究揭示了相对多样化且保存完好的孢粉菌群组合，主要是甲藻囊肿和小孢子。根据记录的指数甲藻囊肿区分了两个著名的间隔甲藻包囊带Hebecysta balmei Interval Zone 和Rhaetogonyaulax rhaetica Interval Zone，并确定了成员的Norian-Rhaetian 年龄。这些甲藻囊肿带的孢粉学含量与澳大利亚的上三叠统带相当。在生物地理学上，记录的孢粉型是欧亚和冈瓦纳元素的混合体，但诺里阶到最早的雷蒂亚元素与冈瓦纳植物群的关系更为密切。