Writers : Dehbozorgi, Afsaneh; supervisor: F. Sajadi, E. Ghaseminegad; advisor: M. Hosseiniun
Refference : M.Sc. Thesis _ Tehran university, Tehran;129p.
Publishing Year : 1383

Abstract :

The palynological investigation of the Kashafrud Formation in Senjeda 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 1651 meters. 50 samples of black shale and fine grain sandstone of this section selected and 250 palynological slides were prepared. This Formation lies unconformably on ophiolitic rocks (Late Permian - Triassic) and faulted against the Shurijeh Formation (Late Jurassic - Early Cretaceous). In this study 47 species of spores (distributed among 30 genera), and 15 species of pollen (distributed among 8 genera are particulary abundant (in contrast with dinoflagellates, fungal spores and acritarchs associated with foraminiferal test lining). 19 species of spores and pollen have been reported from the Kashafrud Formation in Senjedac Section for the first time from Iran. Disappearance of Striatella seebergens and appearance of Contoriles burgeri indicate a Bathonian age for the upper part of the section studied and a Bajocian age for the lower part of the section, which corroborates the faunal (amonite5 .contents) testimony. The presence of Con verrucosisporites pricei Osmundacidites senectus, Murospora florida, Retitriletes facetus ,Sellaspora asperata, Concavissimisporites verrucosus ,orites west bournens testified this age determination Tuberculato
The relative abundance of Kiukisporites, Dictyophyllidites and comparison with palynostratigraphic subdivision of Australian Mesozoic sequences indicate similarities between the Kashafrud palynofloras and the Dictyophyllidites Assemblage Subzone of Fillatof(1975) dated as Toarsian early Bajocian. The Kashafrud palynofloras are also comparable with - Ischyosporites variegatus - Duplexisporites problematicus zone of Ashraf 1977) from Iran and Afghanistan dated as Middle Jurassic. Two biozones (Striatella seebergenise reng and Contignisporite burgeri range zone) were regionally established in Senjedac Section .The association of marine palynomorphs (proximate dinoflagellates Michrystridium and foraminiferal test lining) with spores and pollen collectively indicate an open marine, neàrshore depositional setting for the Kashafrud Formation in Senjedac Section. Inferred natural relationship of the spores and pollen grains imply derivation from a diverse parental flora .of gymnosperms such as Bryophyta, Coniferophyta, Pterophyta Ginkgophyta and Cycadophyta growing under a humid, warm temperature ,conditions during Bajocian - Bathonian
The presence of some dinoflagellates such as Ltonium sub Chytroeisphaeridia chytroeides, Endoscrinium luridum and Gonyaulacysta co accompanied by fringal spores testified the warm conditions. Furtheremore the abundance of Dictyophyiiles Kiuk orites and at tes which are related to Pterophyta indicate the domination of Pterophyta suggestive of a moist warm climate during Bajocian - Bathonian. Kashafrud palynomorphs exhibit closely resemblance to Australian palynomorphs. This suggests similar terrestrial ,vegetation in Iran and Australia during Bajocian - Bathonian Palynomorphs are known to change colour with increasing temperature Comparing the yellowish orange colour of the palynomorphs, especially of the spores and pollen grains, with standard colour chart presented by Traverse (1988), it is clear that the Kashafrud deposits tolerated same chemical changes, marginally mature but not likely to have potential as a commercial source of petroleum. Shemshak group completely differs from .the Kashafrud Formation in this section because of the different lithology lack of coal, nearshore depositional setting and the Bajocian - Bathoniari ,age for the Kashafrud Formation in Senjedac Section.

Subject List : Palinostratigraphy