Document Type : Original Research Paper


1 Assistant Professor, School of Geology, College of Sciences, University of Tehran, Tehran, Iran

2 Associate Professor, College of Sciences, University of Zanjan, Zanjan, Iran


Jurassic deposits a section in south of Zanjan contain various taxa of macro and microfloras. Six plant macrofossil species belonging to five genera of various orders such as Equisetales, Cycadales, Bennettitales, and Pinales (Coniferales) are identified. This section contains seventeen species of palynomorphs in which six spore species allocated to six genera, eight pollen species allocated to five genera, and three dinocyst species allocated to two genera are present. Based on the occurrence of Index fossils such as Ptilophyllum harrisianum, Nilssonia sp. cf. N. bozorga, and Equisetites sp. cf. E. beanii, an early Middle Jurassic (Aalenian-Bajocian) age suggested for these sediments. Therefore, these deposits considered to belong to the Dansirit Formation. Moreover, based on the stratigraphic distribution of index fossils of plant macrofossils, miospores, and dinocysts, three assemblage biozones recognized. These biozones are Nilssonia sp. cf. N. bozorga-Ptilophyllum harrisianum, Klukisporites variegatus-Cycadopites crassimarginis,and Pareodinia ceratophora-Nannoceratopsis triceras Assemblage Zone, respectively. All these biozones are comparable to the other Known Iranian biozones. Therefore, it is concluded that uniform environmental conditions are dominant through North, Central, and East Central of Iran during this interval. Furthermore, because of the occurrence of dinoflagellates, this area was located at the margin of Tethys Ocean.


Aghanabati, A., 1998- Jurassic stratigraphy of Iran. Geological Survey of Iran Publication, Tehran, Iran (In Persian).
Alavi, M. H., Hajian, J., Amidi, M. and Bolourchi, M. H., 1982- Geology of Takab-Saein-Galeh, 1:250000. Geological Survey of Iran, Report No. 50: 99p.
Arjang, B., 1975- Die rato-jurassischen Floren des Iran und Afghanistans. 1. Die Microflora der rato-jurassischen Ablagerungen des Kermaner Beckens (Zentral Iran), Palaeontographica B, Vol. 152 (4–6), pp. 85–148.
Ashraf, A. R., 1977- Die räto-jurassischen Floren des Iran und Afghanistans. 3. Die Mikrofloren der ratischen bis unterkretazischen Ablagerungen Nordafghanistans, Palaeontographica B, Vol. 161 (1–4), pp. 1–97.
Assereto, R., 1966- The Jurassic Shemshak Formation in Central Elburz (Iran), Rivista Italiana di Paleontologia e Stratigrafia, Vol. 72 (4), pp. 1133-1182.
Babakhani, A. and Sadeghi, A., 2004- Geological map of Zanjan: 1:100000, Geological Survey of Iran.
Barnard, P. D. W. and Miller, J. C., 1976- Flora of the Shemshak Formation (Elburz, Iran), Part 3:  Middle Jurassic (Dogger) plants from Khatumbargah, Vasekgah and Imam Manak, Palaeontographica B, Vol. 155, pp. 31-117.
Barnard, P. D. W., 1965- The geology of the upper Djadjerud and Lar valleys (North Iran) II. Palaeontology. Flora of the Shemshak Formation Part 1. Liassic plants from Dorud, Rivista Italiana di Paleontologia e Stratigrafia, Vol. 71 (4), pp. 1123-1168.
Barnard, P. D. W., 1967- The geology of the upper Djadjerud and Lar valleys (North Iran) II. Palaeontology. Flora of the Shemshak Formation Part 2. Liassic plants from Shemshak and Ashtar, Rivista Italiana di Paleontologia e Stratigrafia, Vol. 73 (2), pp. 539-588.
Bharadwaj, D. C. and Kumar, P., 1986- Palynology of Jurassic sediments from Iran: 1, Kerman area, Biological Memoire, Vol. 12 (2), pp. 146-172.
Bolourchi, M. H., 1979- Explanatory text of Kabudar Ahang Quadrangle Map, 1:250000, Geological and Mineral Survey of Iran. Geological Quadrangle D5: 107p.
Bucefalo Palliani, R. B. and Riding, J. B., 2000- A Palynological investigation of the Lower and Lowermost Middle Jurassic strata (Sinemurian to Aalenian) from Yorkshire, UK, Proceedings of Yorkshire Geological Society, Vol. 53 (1), pp. 1-16.
Bunbury, C. J. F., 1851- On some fossil plants from the Jurassic strata of the Yorkshire Coast, Quarterly Journal of Geological Society of London, Vol. 7, pp. 179-194.
Corsin, P. and Stampfli, G., 1977- La formation de Shemshak dans l’Elburz oriental (Iran) flore - stratigraphie – paléogéographie, Geobios, Vol. 10, pp. 509-571. 
Davies, E. H., 1983- The dinoflagellate Oppel-zonation of the Jurassic -Lower Cretaceous sequence in the Sverdrup Basin, arctic Canada, Geological Survey of Canada Bulletin, Vol. 359, 59 p.
De Jersey, N. J., 1970- Triassic miospores from the Blackstone Formation, Aberdare Conglomerate and Raceview Formation, Geological Survey of Queensland publication number, Vol. 348, 41p.
Fakhr, M. S., 1977- Contribution a l'étude de la flore Rhéto – Liasique de la formation de Shemshak de l'Elbourz (Iran), Mémoire de Section de Science, Vol. 5, 178 p., pl. I-LI. Paris. 
Filatoff, J., 1975- Jurassic palynology of the Perth Basin, Western Australia, Palaeontographica B, Vol. 154 (1-4): 1-113.
Fürsich, F. T., Wilmsen, M. and Seyed-Emami, K., 2009- Lithostratigraphy of the Upper Triassic-Middle Jurassic Shemshak Group of northern Iran, Geological Society London, Special Publications, Vol. 312, pp. 120-160.
Gedl, P., 2007- Early Jurassic dinoflagellate cysts from the Kraków-Silesia Monocline, southern Poland: A record from the Blanowice Formation at Mrzygłód, Annales Societatis Geologorum Poloniae, Vol. 77, pp. 147–159.
Harris, T. M., 1961- The Yorkshire Jurassic Flora, I. Thallophyta-Pteridophyta, British Museum (Natural History), 212 p. London.
Hashemi-Yazdi, F., Sajjadi, F. and Hashemi, H., 2014- Palynostratigraphy of Hojedk Formation at the Eshkelli Stratigraphic section, North Kerman on the basis of miospores, Paleontology, Vol. 2, no. 1, pp. 111-127 (In Persian).
Helby, R., Morgan, R. and Partridge, A. D., 2004- Updated Jurassic-Early Cretaceous Dinocyst Zonation NWS Australia, Geoscience Australia Publication, ISBN: 1920871012. Chart 2.
Huault, V., 1999- Zones de kystes de dinoflagelles de l’intervalle Aalenien-Oxfordien sur la bordure meridionale du bassin de Paris:  Dinoflagellate cyst zonation of the Aalenian-Oxfordian interval on the southern margin of the Paris Basin, Review of Palaeobotany and Palynology, Vol. 107, pp. 145–190.
Ibrahim, M. I. A., Aboul Ela, N. M. and Kholeif, S. E., 2001- Palynostratigraphy of Jurassic to lower Cretaceous sequences from the Eestern Desert of Egypt, Journal of African Earth Sciences, Vol. 32 (2), pp. 269-297.
Ibrahim, M. I. A., Kholeif, S. E. and Al-Saad, H., 2003- Dinoflagellate cyst Biostratigraphy and Paleoenvironment of the Lower-Middle Jurassic succession of Qatar, Revue Española de Micropaleontología, Vol. 35, pp. 171-194.
Kilpper, K., 1968- Einige Bennettiteen-Blätter aus dem Lias von Karmozd-Zirab,Journal of the Linnean Society (Botany),  Vol. 61, pp. 129-135.
Kimyai, A., 1968- Jurassic plant microfossils from the Kerman region, The Bulletin of the Iranian Petroleum Institute, pp. 3-23.
Koppelhus, E. B. and Hansen, C. F., 2003- Palynostratigraphy and palaeoenvironment of the Middle Jurassic Sortehat Formation (Neill Klinter Group), Jameson Land, East Greenland, Geological Survey of Denmark and Greenland Bulletin, Vol. 1, pp. 777–811.
Koppelhus, E. B. and Nielsen, L. H., 1994- Palynostratigraphy and palaeoenvironments of the Lower to Middle Jurassic Bagå Formation of Bornholm, Denmark, Palynology Vol.18, pp. 139-194.
Navidi-Izad, N., Sajjadi, F., Dehbozorgi, A. and Hashemi-Yazdi, F., 2015- Palynostratigraphy and sedimentary palaeoenvironment of Dalichi Formation at the Dictash stratigraphic section, NE Semnan, Journal of Stratigraphy and Sedimentology Researches, Esfahan, Vol. 57 (4), pp. 21-46 (In Persian).
Phipps, D. and Playford, G., 1984- Laboratory techniques for extraction of palynomorphs from sediments, Department of Geology, University of Queensland, Vol. 11, pp. 1–29.
Pocock, S. A. J., 1970- Palynology of the Jurassic sediments of western Canada, Terrestrial species, Palaeontographica B, Vol. 130 (1-2), pp. 12-72, continued in (3-6), pp. 73-136.
Reiser, R. F. and Williams, A. J., 1969- Palynology of the Lower Jurassic sediments of the northern Surat Basin, Queensland, Geological Survey of Queensland, Palaeontology Paper, Vol. 339 (15).
Riding, J. B. and Thomas, J. E., 1992- Dinoflagellate cysts of the Jurassic System” In: Powel, A.J. (ed.), “A Stratigraphic Index of Dinoflagellate cysts, British Micropalaeontological Society Publication Series, Chapman & Hall, pp. 7-98.
Riding, J. B., Fedorova, V. A. and Ilyina, V. I., 1999- Jurassic and Lowermost Cretaceous dinoflagellate cyst biostratigraphy of the Russian Platform and Northern Siberia, Russia, American Association of Stratigraphic Palynologists Foundation.
Sajjadi, F., Hashemi, H. and Dehbozorgi, A., 2007- Middle Jurassic palynomorphs of the Kashafrud Formation, Koppeh Dagh Basin, Northeastern Iran, Micropaleontology,Vol. 53 (5), pp. 391-408
Schenk, A., 1887- Fossile Pflanzen aus der Albours-Kette, Bibliotheca Botanica, Vol. 6, pp. 1-12, 9 pls.
Schweitzer, H. J. and Kirchner, M., 1996- Die rhäto-jurassischen Floren des Iran und Afghanistans.  9.  Coniferophyta, Palaeontographica B, Vol. 238 (4-6), pp. 77-139.
Schweitzer, H. J. and Kirchner, M., 1998- Die rhäto-jurassischen Floren des Iran und Afghanistans. 11. Pteridospermophyta und Cycadophyta I. Cycadales, Palaeontographica B, Vol. 248 (1-3), pp. 1-85.  
Schweitzer, H. J. and Kirchner, M., 2003- Die rhäto-jurassischen Floren des Iran und Afghanistans 13. Cycadophyta. III. Bennettitales, Palaeontographica B, Vol. 264 (1-6), pp. 1-166.
Schweitzer, H. J. U., Kirchner, M. and Van Konijnenburg-van Cittert, J. H. A., 2000- The Rhaeto-Jurassic flora of Iran and Afghanistan. 12. Cycadophyta II. Nilssoniales, Palaeontographica B, Vol. 279 (1-6), pp. 1-108.
Schweitzer, H. J., Schweitzer, U., Kirchner, M., Van Konijnenburg-van Cittert, J. H. A., Van der Burgh, J. and Ashraf, R. A., 2009- The Rhaeto-Jurassic flora of Iran and Afghanistan. 14.  Pterophyta, Leptosporangiatae, Palaeontographica B, Vol. 279 (1-6), pp. 1-108.
Schweitzer, H. J., van Konijnenburg- van Cittert, J. H. A. and van Der Burg, J., 1997- The Rhaeto-Jurassic flora of Iran and Afghanistan. 10. Bryophyta, Lycophyta, Sphenophyta, Pterophyta-Eusporangiate and Protoleptosporangiate, Palaeontographica B, Vol. 243, pp. 103-192.
Seward, A. C., 1894- The Wealden Flora, Part I.- Thallophyta- Pteridophyta, Catalogue of the Mesozoic plants in the Department of Geology, British Museum. 179 pp. London.
Stöcklin, J. and Eftekhar-nezhad, J., 1969- Explanatory Text of the Zanjan Quadrangle Map, Geological Survey of Iran, report No D4, 61p. [with 1:250000 Geological map].
Stöcklin, J. and Setudehnia, A., 1991- Stratigraphic Lexicon of Iran, Geological Survey of Iran, Tehran, Iran, Report No. 18, 379 p.
Vaez-Javadi, F. and Abbasi, N., 2012- Plant macrofossils of Baladeh area (Central Alborz), dating and Biostratigraphy, Journal of Stratigraphy and Sedimentology Researches, Esfahan, Vol. 48 (3), pp. 37-64. (In Persian)
Vaez-Javadi, F. and Allameh, M. 2015- Biostratigraphy of the Bazehowz Formation at its Type section, South West Mashhad based on plant macrofossils, Geopersia, Vol. 5 (1), pp. 27-44.
Vaez-Javadi, F. and Ghavidel-Syooki, M., 2005- Systematic study of Spore and Pollen in Shemshak Formation, Jajarm area, Geosciences, Vol.12 (56), pp. 94-123.
Vaez-Javadi, F. and Ghavidel-Syooki, M. and Ghasemi-Nejad, E., 2003- Biostratigraphy of Shemshak Formation in Ozon Mountain, Jajarm, based on Dinoflagellata. Journal of Science, University of Tehran, Vol. 29 (1), pp. 141-160.
Vaez-Javadi, F. and Mirzaei-Ataabadi, M., 2006- Jurassic plant macrofossils from the Hojedk Formation, Kerman area, east-central Iran, Alcheringa, 30, pp. 63-96.
Vaez-Javadi, F. and Namjoo, S., 2015- Biostratigraphy of Hojedk Formation in the North Kouchekali, west of Tabas and its climate analysis with the other similar florizones, Paleontology. Paleontology, 3 (2), pp. 220-243.
Vaez-Javadi, F., 2006- Plant fossil remains from the Rhaetion of shemshak formation. Narges-Chal area, Alborz, NE Iran, Rivista Italiania di paleontoligia e stratigrafia, Vol. 112 (3), pp. 397-416.
Vaez-Javadi, F., 2008- Plant macrofossils of Iran. Department of Environment Publications, 256p.
Vaez-Javadi, F., 2011- Middle Jurassic flora from the Dansirit Formation of the Shemshak Group, Alborz, north Iran, Alcheringa, Vol. 35, pp. 77-102.
Vaez-Javadi, F., 2012- Plant Macrofossils from Tiar Area, South Amol, Dating and Correlation with the other Florizone of Iran, Journal of Stratigraphy and Sedimentology Researches,Esfahan, Vol. 21 (83), pp. 229-237 (In Persian).
Vaez-Javadi, F., 2014- Triassic and Jurassic Floras and Climate of Central-East Iran, Geological Survey of Iran, Rahi Publication, Tehran, 254p.
Vaez-Javadi, F., 2015- Plant macrofossils and Biostratigraphy of the Calshaneh section, NW Tabas and its palaeoclimate analysis, Journal of Stratigraphy and Sedimentology Researches, Esfahan, Vol. 61 (4), pp. 105-123 (In Persian).
Vaez-Javadi, F., 2016- Integrated Biostratigraphy of Plant Macrofossils, Miospores and Dinocysts of Hojedk Formation at the South Kouchekali, Tabas, 34th conference of Geosciences, Tehran, Geological Survey of Iran.
Vaez-Javadi, F., 2017- Palynostratigraphy of the Middle Jurassic sediments in Hojedk Formation, Tabas Block, East-Central Iran, Palaeobotanist, Vol.66, pp. 47-60.
Vaez-Javadi, F., 2018- Dinoflagellate Palynostratigraphy of Middle Jurassic of the Hojedk Formation, Tabas, Central-East Iran and its correlation to the other Palynomorph zones in Iran and elsewhere, Geosciences (In Persian).
Van Helden, B. G. T., 1977- Correlation of microplankton assemblages with ammonite faunas from the Jurassic Wilkie Point Formation, Prince Patrie Island, District of Franklin, Geological Survey of Canada, Vol. 77-LB, pp. 163-171.
Vijaya and Sen, K. K., 2005- Palynological study of the Dubrajpur formation in the Mesozoic succession, Pachambi Area, Birbhum Coalfiel, West Bengal, Journal of the Palaeontological Society of India, Vol. 50 (1), pp. 121-133.
Weiss, M., 1989- Die Sporenfloren aus Rät und Jura südwest-Deutscglands und ihre beziehung zur Ammoniten-Stratigraphie, Palaeontographica B, Vol. 15 (1-6), pp. 1-168.