Dinoflagellate cysts from the Upper Triassic (Rhaetian) strata of the Tabas Block, East - Central Iran

Document Type : Research Paper


1 Exploration Directorate of National Iranian Oil Company, Tehran, Iran

2 Department of Geology, Faculty of Sciences, University of Tehran, Tehran, Iran



Rhaetian strata from the Nayband Formation of the Tabas block, East- Central Iran, were studied palynologically. The material
examined contained moderately diverse and well-preserved dinoflagellate cyst assemblages which lead to the identification of
Rhaetogonyaulax rhaetica Zone. The assigned age of this dinozone (Rhaetian) is justified by plant fossils such as Equisetites
arenaceus, Scytophyllum persicum, Pterophyllum bavieri, Pterophyllum aequale and Nilssoniopteris musafolia recorded from these
strata. The dinoflagellate cysts show close similarities with assemblages reported from Australia, Northwest Europe, Arctic Canada
and Northern Iran. Furthermore, the associated marine palynomorphs (dinoflagellate cysts), accompanied by spores grain indicate a
nearshore depositional environment for the Late Triassic (Rhaetian) deposits in Tabas Block of Iran.


Article Title [Persian]

داینوسیستهای تریاس فوقانی (رتین) در بلوک طبس، شرق ایران مرکزی

Authors [Persian]

  • حسین صباغیان 1
  • ابراهیم قاسمی نژاد 2
  • محمد رضا آریانسب 1
1 کارشناس مدیریت اکتشاف، تهران
2 دانشیار زمین شناسی دانشگاه تهران
Abstract [Persian]

رسوبات به سن رتین مربوط به سازند نایبند در بلوک طبس، شرق ایران مرکزی مورد مطالعه پالینولوژی قرار گرفت. در بررسی نمونه ها، مشخص شد که داینوسیستها در این نمونه ها از تنوع و حفظ شدگی خوبی برخوردارند که منجر به شناسایی بایوزون Rhaetogonyaulax rhaetica در این رسوبات شد. سن بدست آمده برمبنای این بایوزون(رتین) در تطابق کامل با سن بدست آمده براساس فسیل های گیاهی نظیر Equisetites arenaceus, Scytophyllum persicum, Pterophyllum bavieri, Pterophyllum aequale و Nilssoniopteris musafolia می باشد که در این رسوبات گزارش شده اند. اجتماع داینوفلاژله های شناسایی شده شباهت زیادی با اجتماع داینوفلاژله های گزارش شده از استرالیا، شمال غرب اروپا، آرکتیک کانادا و شمال ایران دارند. همچنین همراهی پالینومورفهای خشکی(گرده و هاگ) با پالینومورفهای دریایی(داینوفلاژله) نشانگر محیط رسوبی نزدیک ساحل در رسوبات تریاس فوقانی بلوک طبس می باشد.

Keywords [Persian]

  • تریاس فوقانی
  • داینوسیست ها
  • پالئوبیوژئوگرافی
  • بلوک طبس
  • ایران
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