پالینواستراتیگرافی سازند کشف رود در برش سنجدک، جنوب شرق مشهد

Palynostratigraphy of the Kashafrud Formation in Senjedac Section, southeast of Mashhad

Abstract:

The palynological investigation of the Kashafrud Formation in Senjedac Section has been done. This section which is situated in southeast of Mashhad, east of Fariman, contains of shale, sandstone and Conglomerate with a thickness of about ۱۶۵۱ meters. ۵۰ samples of black shale and fine grain sandstone of this section selected and ۲۵۰ palynological slides were prepared. In this study ۴۷ species of spores (distributed among ۳۰ genera), and ۱۵ species of pollen (distributed among ۸ genera) are particulary abundant (in contrast with dinoflagellates and fungal spores associated with foraminiferal test lining). ۱۹ species of spore & pollen has been reported for the first time from Iran. Disappearance of Striatella seebergensis and appearance of Contignisporites burgeri indicate a Bathonian age for the upper part of the studied section and a Bajocian age for the lower part of the section, which corroborates the faunal (amonites contents) testimony. The presence of Converrucosisporites pricei, Osmundacidites senectus, Murospora florida, Retitriletes facetus, Sellaspora asperata, Concavissimisporites verrucosus Tuberculatosporites westbournensis testified this age determination. According to abundant presence of Klukisporites , Dictyophyllidites and compare with the zones which identified in Australia by Fillatof (Fillatof, ۱۹۷۵) with the name Dictyophyllidites Assemblage Subzone and in Iran & Afghanistan by Ashraf (Ashraf, ۱۹۷۷) with the name Ischyosporites variegatus - Duplexisporites problematicus zone a Middle Jurassic (Bajocian - Bathonian) age was proposed for this section. In Senjedac section ۲ biozones (Striatella seebergensis Range Zone & Contignisporites burgeri Range Zone) were regionally established.