Plant megafossil systematic studies from Shemshak Formation of Abyek area, Gazvin

The main formations with coal resources are Shemshak and Hojedk in Iran. They have special plant mega fossils that show Rrhetian- Liassic geological age for Shemshak formation. Studied region is located in the north of Abyek area. Shemshak formation with high development outcrops is formed of sandstone, siltstone, shale and claystone. Abyek coal resources lie in central Alborz. Biostrtigraphical characteristics of studied region belong to different ages. Outcrop of Precambrian formations torecent is available. The oldest formation is Kahar that lied down of Soltaniye formation. Paleoclimatologic investigations determined warm and humid ecology and semitropical environment for Shemshak formation. Most remaining of past plants are their leaves and main association contains 9 genuses and 1 species that follows:Zamites sp., Otozamites sp., Anomozamites sp., Nilssoniopteris sp. Ctenis sp., Cycadites sp., Nilssonia sp., Dictyophyllum sp., Cladophlebis sp., Pterophyllum bavieni.