Writers : Sajadi,Fereshte; Hadad Tavokli,Elham
Refference : 9th symposium of geological society of Iran, Tehran, Teacher Training university
Publishing Year : 1384

Abstract :

Diverse, moderately well preserved palynofloras, together with minor dinoflagelatecysts occur in the mainly shale sediments of the Kashafrud Formation at the Ghalesangi Section, east of Mashhad. A total of 83 spore and pollen species have been identified. Of these, the miospores are mainly radios symmetrical and triletes; wheras the pollen are represented by mnonosulcate and non_ striate bisaccate taxa. Dinofla ge/late and fun gal spores occur in minor proportions. The relative abundance of Klukisporites and Dictyophyllidites and comnparision with palynostratigraphic subdivision of Australia, iran and Aj!hanstan, indicate a middle Jurassic age for the stud>' section. Moreover disappearance of Striate/la seebergensis and appearance of Contignisporites burgeri suggest a Bajocian.. Bathonian age for this interval, in the stud>' .section, the two inter vision consisting of Striatella seebergensis and Contignisporites burgeri which previously established from Senjedac section of Kashafrud (in southeast of Mashhad) have been recognized. inferred natural relationships of the dispersed spore and pollen of Kashafrud palynofloras imply derivation mostly from Pterophyta (Ferns) and Coniferophyta, growing under moist and tropical to sub tropical condition during Bajocian.. Bathonian. The percentage of palynological group such as marine palynomorphs, Amorph organic matter (AOM) and palynomacerals signifies an open ,marine, near shore depositional setting with high content of oxygen for the study section. Comparing the yellowish orange color of the palynomorphs with standard color chart presented by Batten (1980), indicate that the Kashafrud palynofloras tolerated some chemical changes, marginally mature but not likely to have potential as a commercial source of petroleum. A detailed comparison of the Ghale_sangi palynoflora with the Senjedac suite indicate that the two assemblages feature significant quantitative and qualitative palaeofloristic similarities and suggest a similar depositional and climate conditions in the east and southeast of Mashhad during the Bajocian_Bathonians.

Subject List : Plants-fossil